K Service Source Macintosh Color Classic II/ Performa 275
K Service Source Basics Macintosh Color Classic II/ Performa 275
Basics Overview - 1 Overview This manual includes complete repair procedures for the Macintosh Color Classic II/Performa 275.
K Service Source Specifications Macintosh Color Classic II/ Performa 275
Specifications Configurations - 1 Configurations Standard Options 4 MB RAM, 256K VRAM, 3.5-in. hard drive (many sizes), internal 1.4 MB floppy drive, user-removable logic board, 9in. color display, built-in speaker and microphone, keyboard, mouse, ADB and power cables, system software installed on hard drive (requires System 7.
Specifications Processor - 2 Processor CPU Coprocessor Addressing Motorola 68030 microprocessor 33 MHz Built-in Paged Memory Management Unit (PMMU) 256-byte instruction and data caches Socket for optional Motorola 68882 floating-point coprocessor 33 MHz 16-bit data bus 32-bit address bus 16-bit internal registers
Specifications Memory - 3 Memory RAM 4 MB of dynamic RAM on board Expandable to 10 MB (100 ns or faster SIMMs) Dual SIMM expansion slot (two 30-pin connectors) Includes RAM disk software ROM 1 MB of main ROM on board; 2 MB maximum of main ROM PRAM 256 bytes of clock/calendar/parameter memory Long-life lithium battery
Specifications VRAM Memory - 4 256K of VRAM on board Expandable to 512K of VRAM with 256K VRAM SIMM (100 ns or faster VRAM SIMM) 68-pin VRAM SIMM connector
Specifications Disk Storage - 5 Disk Storage Floppy Drive Internal 1.4 MB Apple SuperDrive Hard Drive 3.
Specifications I/O Interfaces - 6 I/O Interfaces Serial Two RS-232/RS-422 serial ports; mini DIN-8 connectors SCSI One SCSI parallel port; DB-25 connector Connects up to six external SCSI devices Apple Desktop Bus Two ADB ports; mini DIN-4 connector Maximum of three ADB devices recommended Maximum current draw: 500 mA (Mouse draws 10 mA, keyboard draws 25 mA)
Specifications Sound Processor Direct Slot I/O Interfaces - 7 Sound-input, external microphone port, 8-bit monaural sound, sampled at 22 or 11 kHz Monophonic sound-output jack for external audio amplifier or headphones Macintosh LC-compatible, 96-pin PDS expansion connector
Specifications I/O Devices - 8 I/O Devices Keyboard Standard 80-key Apple keyboard with numeric keypad; ADB connector Soft power-on switch 2.
Specifications Sound and Video - 9 Sound and Video Sound Generator VRAM Video Display Monophonic 8-bit digital-analog conversion using 22 KHz sampling rate for sound input (capable of driving stereo headphones or other stereo equipment through the sound jack) Standard: 256K of VRAM on board; displays up to 256 colors; Supports 1, 2, 4, or 8 bits per pixel Enhanced: 512K of VRAM; displays up to 32,000 colors; Supports 1, 2, 4, 8, or 16 bits per pixel Built-in, 10-in. diagonal (254 mm), 9-in.
Specifications Electrical - 10 Electrical Line Voltage 90–240 VAC; Universal power supply Frequency 47–63 Hz, single phase Maximum Power 100 W
Specifications Physical - 11 Physical Dimensions Weight Height: 14.5 in. (37.0 cm) Width: 9.9 in. (25.2 cm) Depth: 12.6 in. (32.15 cm) 22.5–23.2 lb. (10.2–10.
Specifications Environmental - 12 Environmental Operating Temperature Storage Temperature 50–104° F (10–40° C) -40 to 116° F (-40 to 47° C) Relative Humidity 20–95% noncondensing Altitude 0–15,000 ft.
K Service Source Troubleshooting Macintosh Color Classic II/ Performa 275
Troubleshooting General/ - 1 General The Symptom Charts included in this chapter will help you diagnose specific symptoms related to your product. Because cures are listed on the charts in the order of most likely solution, try the first cure first. Verify whether or not the product continues to exhibit the symptom. If the symptom persists, try the next cure. (Note: If you have replaced a module, reinstall the original module before you proceed to the next cure.
Troubleshooting Symptom Charts/Video - 2 Symptom Charts Video Screen is black, too dark, or too bright; audio and drive operate 1 2 3 4 5 6 Screen is bright and audio is present, but no video information is visible 1 2 3 Adjust contrast button on front bezel. Adjust brightness. Use Brightness Control Panel. Check yoke cable connection. Perform video adjustments. Refer to “Video” in Adjustments chapter. Replace analog board. Replace CRT. Perform video adjustments.
Troubleshooting Symptom Charts/Video (Continued) - 3 Video (Continued) Single vertical or horizontal line is displayed 1 2 Replace analog board. Replace CRT. Predominant color tint or color cannot be adjusted 1 Perform video adjustments. Refer to “Video” in Adjustments chapter. Replace analog board. Replace CRT if red, green, or blue cannot be turned off using appropriate controls.
Troubleshooting Symptom Charts/Video (Continued) - 4 Video (Continued) Picture breaks into diagonal lines, or picture rolls vertically or horizontally Replace analog board. Out of convergence (color bleeds from text or lines) 1 Black screen spots (burnt phosphors) Replace CRT. 2 3 Perform convergence adjustment. Refer to “Convergence” in Adjustments chapter. Replace analog board. Replace CRT.
Troubleshooting Symptom Charts/Video (Continued) - 5 Video (Continued) Screen jitters or flashes 1 2 3 Out of focus 1 2 3 Verify that adjacent computer equipment is properly grounded. Move electrical devices away from monitor. Temporarily shut off all fluorescent lights in area. Check that all ground cables are secure. Replace analog board. Perform focus adjustment. Refer to “Focus” in Adjustments chapter. Replace analog board.
Troubleshooting Symptom Charts/Video (Continued) - 6 Video (Continued) Flashing or wavy screen or monitor emits high-pitched noise Replace analog board. Raster size too short/ tall or narrow/wide 1 Linearity bad (size of text/graphics differs at top, bottom, or sides of screen) 2 Adjust horizontal or vertical size control. Refer to Adjustments chapter. Replace analog board. Replace analog board.
Troubleshooting Symptom Charts/Video (Continued) - 7 Video (Continued) Raster tilted or shifted 1 2 3 4 Verify that distortion is not due to environmental conditions (move monitor to different location). Refer to “Monitor Distortion” in Basics chapter of any large-screen monitor manual. Perform appropriate geometric adjustments. Perform yoke adjustment. Refer to “Yoke” in Adjustments chapter. Replace analog board.
Troubleshooting Symptom Charts/Video (Continued) - 8 Video (Continued) Raster distorted (barrel-shaped, corners not square, stretched or compressed at top of display, or sides not perpendicular) 1 Raster not centered 1 2 3 4 2 3 Verify that distortion is not due to environmental conditions (move monitor to different location). Refer to “Monitor Distortion” in Basics chapter of any large-screen monitor manual. Perform appropriate geometric adjustments. Replace analog board.
Troubleshooting Symptom Charts/Floppy Drives - 9 Floppy Drives Audio and video are present, but internal floppy drive does not operate 1 2 3 Disk ejects; display shows icon with blinking “X” 1 2 3 4 Replace bad disk with known-good disk. Replace floppy drive. Replace logic board. Retain customer’s SIMMs, math coprocessor, and PDS card. Replace floppy drive cable. See “Flat-Cable Assembly” in Take Apart. Replace bad system disk with known-good system disk. Replace floppy drive. Replace logic board.
Troubleshooting Symptom Charts/Floppy Drives (Continued) - 10 Floppy Drives (Continued) Unable to insert disk all the way 1 2 3 Does not eject disk 1 2 3 To eject previously inserted disk, insert opened paper clip into hole beside floppy drive. Switch off system and hold mouse button down while switching system on (to complete eject cycle). Replace floppy drive. Insert opened paper clip into hole beside floppy drive.
Troubleshooting Symptom Charts/Floppy Drives (Continued) - 11 Floppy Drives (Continued) Internal floppy drive runs continuously 1 2 3 4 Replace bad disk with known-good disk. Replace floppy drive. Replace logic board. Retain customer’s SIMMs, math coprocessor, and PDS card. Replace floppy drive cable. See “Flat-Cable Assembly” in Take Apart.
Troubleshooting Symptom Charts/Hard Drives - 12 Hard Drives Internal or external hard drive does not operate 1 2 3 4 5 6 Works with internal or external SCSI device but does not work with both 1 2 3 Verify that SCSI loopback card is not attached. Verify that internal hard drive has all three terminating resistor packs on circuit board. Verify that external drive is properly terminated. Replace hard drive. Replace logic board. Retain customer’s SIMMs, math coprocessor, and PDS card.
Troubleshooting Symptom Charts/Peripheral - 13 Peripheral Cursor does not move 1 2 3 4 Cursor moves, but clicking mouse button has no effect 1 2 Check mouse connection. If mouse was connected to keyboard, connect it to rear ADB port instead. If mouse works, replace keyboard. If mouse does not work in any ADB port, replace mouse. Replace logic board. Retain customer’s SIMMs, math coprocessor, and PDS card. Replace mouse. Replace logic board. Retain customer’s SIMMs, math coprocessor, and PDS card.
Troubleshooting Symptom Charts/Peripheral (Continued) - 14 Peripheral (Continued) Cannot double-click to open application, disk, or server 1 2 3 4 5 No response to any key on keyboard 1 2 3 4 Remove extra system files on hard drive. Clear parameter RAM. Hold down
Troubleshooting Symptom Charts/Peripheral (Continued) - 15 Peripheral (Continued) Known-good ImageWriter or ImageWriter II does not print 1 2 Known-good LaserWriter does not print 1 2 3 4 3 Make sure that Chooser and Control Panel are set correctly. Replace printer driver and system software with knowngood. Replace printer interface cable. Replace logic board. Retain customer’s SIMMs, math coprocessor, and PDS card. Make sure that Chooser and Control Panel are set correctly.
Troubleshooting Symptom Charts/Miscellaneous - 16 Miscellaneous Clicking, chirping, or thumping sound 1 Smoke/odor Replace analog board. No video, no audio, and no drive operation 1 2 3 4 5 2 3 Verify that logic board power cable is connected at J12 on logic board. Replace analog board. Replace logic board. Retain customer’s SIMMs, math coprocessor, and PDS card. Connect power cord. Switch power on. Replace power cord. Replace analog board. Replace logic board.
Troubleshooting Symptom Charts/Miscellaneous (Continued) - 17 Miscellaneous (Continued) “Sad Macintosh” icon 1 2 3 Replace bad disk with known-good disk. Replace RAM SIMMs on logic board. Replace logic board. Retain customer’s SIMMs, math coprocessor, and PDS card. Screen shows “Sad Macintosh” icon and black vertical lines; screeching sound 1 2 Replace RAM SIMMs on logic board. Replace logic board. Retain customer’s SIMMs, math coprocessor, and PDS card.
K Service Source Take Apart Macintosh Color Classic II/ Performa 275
Take Apart Logic Board - 1 Logic Board No preliminary steps are required before you begin this procedure. Caution: Follow proper ESD precautions: use a grounded workbench pad, and always wear a grounding wriststrap.
Take Apart Logic Board - 2 1 2 I/O Door If necessary, remove the two security screws from the I/O door. Push down the two latches until the I/O door snaps open. Remove the door from the rear housing.
Take Apart Logic Board - 3 3 Logic Board Grasp the logic board firmly with both hands and pull it straight out of the chassis. Place the logic board on a grounded workbench pad.
Take Apart Logic Board - 4 Replacement Note: If you are replacing a defective logic board, remove the RAM and VRAM SIMMs (if installed), 68882 math coprocessor, and PDS card. Install these components on the replacement logic board. Replacement Caution: After reconnecting the logic board, make sure there are no bent metal tabs on the chassis that could contact the bottom of the logic board and short out the board.
Take Apart Rear Housing - 5 Rear Housing Rear Housing No preliminary steps are required before you begin this procedure. Warning: This product contains high voltage and a high-vacuum picture tube. To prevent injury, review CRT safety and discharge instructions in Bulletins/ Safety.
Take Apart Rear Housing - 6 1 2 Using a long-handled Torx screwdriver, remove the four case screws. If necessary, remove the two security screws from the I/O door. Using a case spreader (pull-apart tool), separate the housing from the chassis. Carefully lift the rear housing and set it aside.
Take Apart Rear Housing - 7 The edges of the metal chassis may be sharp. When moving the computer with the rear housing off, be sure to handle the chassis carefully. ±Warning: Replacement Note: If you are replacing a damaged rear housing, first remove the fan (see the “Fan” topic in this chapter).
Take Apart Analog Board - 8 Analog Board Before you begin, • Remove the rear housing • Discharge the CRT • Remove the anode cap This product contains high voltage and a high-vacuum picture tube. To prevent injury, review CRT safety and discharge instructions in Bulletins/ Safety. ±Warning: Never use a grounding wriststrap until after discharging the CRT.
Take Apart Analog Board - 9 1 Ground Wire Unhook the video board ground wire from the CRT grounding strap. Replacement Caution: When replacing the analog board, be sure to securely reconnect the ground wire to the CRT grounding strap. Switching on system power without reconnecting the ground strap could damage components.
Take Apart Analog Board - 10 2 Video Board Note: If sealant holds the video board in place, cut the sealant with an art knife. Carefully pull the video board straight off the neck of the CRT.
Take Apart Analog Board - 11 3 Degauss Cable Microphone Cable 4 5 Yoke Cable Using a flat-blade screwdriver, release the connector latch and disconnect the degauss cable from analog board connector BP2. Disconnect the yoke cable from analog board connector BD1. Disconnect the two halves of the microphone cable.
Take Apart Analog Board - 12 6 Chassis 7 Analog Board Note: When removing the analog board in this step, be careful not to damage the speaker cable that is connected beneath the analog board. Pull out the analog board approximately two inches and align the edge of the board with cutouts in the plastic guide. Lift out the analog board and place it on the workbench pad.
Take Apart Analog Board - 13 8 9 Speaker Cable Disconnect the two halves of the speaker cable that are located beneath the analog board. Place the analog board on a grounded workbench pad.
Take Apart Speaker - 14 Speaker Before you begin, • Remove the rear housing • Discharge the CRT • Remove the anode cap • Remove the analog board Warning: This product contains high voltage and a high-vacuum picture tube. To prevent injury, review CRT safety and discharge instructions in Bulletins/ Safety.
Take Apart Speaker - 15 Never use a grounding wriststrap until after discharging the CRT. ±Warning: Remove the speaker from the two hook loop fasteners on the chassis.
Take Apart Floppy Drive - 16 Floppy Drive Before you begin, • Remove the rear housing • Discharge the CRT • Remove the anode cap • Remove the analog board • Remove the speaker This product contains high voltage and a high-vacuum picture tube. To prevent injury, review CRT safety and discharge instructions in Bulletins/ Safety.
Take Apart Floppy Drive - 17 Never use a grounding wriststrap until after discharging the CRT. ±Warning: Floppy Drive 1 2 Floppy Drive Cable Disconnect the floppy drive cable and push it through the hole in the plastic chassis. Depress the mounting tab and pull the floppy drive straight out of the chassis mounting channel. Note: The mounting tab may catch beneath the front of the drive mount.
Take Apart Floppy Drive - 18 back and it will pop over the tab. Replacement Note: If you are replacing a defective floppy drive, remove the four carrier mounting screws and separate the drive from the plastic carrier. Remove the shield from the drive mechanism.
Take Apart Hard Drive - 19 Hard Drive Hard Drive Before you begin, • Remove the rear housing • Discharge the CRT • Remove the anode cap • Remove the analog board Warning: This product contains high voltage and a high-vacuum picture tube. Hard Drive To prevent injury, review Power Cable CRT safety and discharge instructions in Bulletins/ Safety.
Take Apart Hard Drive - 20 Hard Drive Never use a grounding wriststrap until after discharging the CRT. ±Warning: 1 2 Hard Drive Data Cable Disconnect the hard drive data and hard drive power cables. Push the cables through the hole in the plastic chassis.
Take Apart Hard Drive - 21 3 Raise the mounting tab and pull the hard drive straight out of the chassis mounting channel. Replacement Note: For information on removing the hard drive from the carrier and returning drives, cables, and carriers to Apple, refer to Additional Procedures in the Hard Drives manual.
Take Apart Chassis - 22 Chassis Chassis Before you begin, • Remove the rear housing • Discharge the CRT • Remove the anode cap • Remove the analog board Warning: This product contains high voltage and a high-vacuum picture tube. To prevent injury, review CRT safety and discharge instructions in Bulletins/ Safety.
Take Apart Chassis - 23 Chassis Never use a grounding wriststrap until after discharging the CRT. ±Warning: 1 2 Bezel Open the two release tabs on one side of the chassis and raise that side of the chassis. To keep the side of the chassis raised, insert a small flat-blade screwdriver between the chassis and the bezel.
Take Apart Chassis - 24 3 4 Chassis Using a small flat-blade screwdriver, pry open the two release tabs on the other side of the chassis and raise the chassis. Lift the chassis straight out of the bezel. Replacement Note: If you are replacing a damaged chassis, first remove the speaker, floppy drive, hard drive, logic board, pushbutton board, and flat-cable assembly. Refer to the appropriate topics in this chapter.
Take Apart Pushbutton Board - 25 Pushbutton Board Before you begin, • Remove the rear housing • Discharge the CRT • Remove the anode cap • Remove the analog board • Remove the chassis This product contains high voltage and a high-vacuum picture tube. To prevent injury, review CRT safety and discharge instructions in Bulletins/ Safety.
Take Apart Pushbutton Board - 26 grounding wriststrap until after discharging the CRT. 1 Chassis 2 3 Mounting Tabs Metal Tabs Bottom Shield Cable Raise and push out the mounting tabs along both sides of the bottom shield. Remove the bottom shield from the chassis. Set the shield aside. Replacement Caution: When replacing the bottom shield on the chassis, make sure none of the metal tabs along the bottom (rear) edge of the shield is bent up (toward the logic board).
Take Apart Pushbutton Board - 27 could contact and short out the logic board. 4 Push-Button Board 5 Connector Using a T-8 Torx driver, remove the two screws that secure the pushbutton board to the chassis. Disconnect the pushbutton board from the cable connector. Replacement Note: Reconnect the cable to the pushbutton board before reinstalling the board on the chassis.
Take Apart Flat-Cable Assembly - 28 Flat-Cable Assembly Flat-Cable Assembly Before you begin, • Remove the rear housing • Discharge the CRT • Remove the anode cap • Remove the analog board • Remove the chassis • Remove the logic board • Remove the speaker • Remove the floppy drive • Remove the hard drive • Remove the pushbutton board
Take Apart Flat-Cable Assembly - 29 This product contains high voltage and a high-vacuum picture tube. To prevent injury, review CRT safety and discharge instructions in Bulletins/ Safety. ±Warning: 1 Small Connector Bridge Analog Board Cables 2 3 Release the plastic latch and remove the small connector bridge (to the analog board) from the chassis. Turn over the chassis.
Take Apart Flat-Cable Assembly - 30 4 Large Connector Bridge 5 through the access hole in the chassis. Release the three plastic latches and remove the large connector bridge (to the logic board) from the chassis. Remove the drive cables from the plastic cable retainers, and remove the flat-cable assembly. Replacement Note: The plastic cable retainers on the chassis fit the width of the drive cables.
Take Apart Microphone Assembly - 31 Microphone Assembly Before you begin, • Remove the rear housing • Discharge the CRT • Remove the anode cap This product contains high voltage and a high-vacuum picture tube. To prevent injury, review CRT safety and discharge instructions in Bulletins/ Safety.
Take Apart Microphone Assembly - 32 Never use a grounding wriststrap until after discharging the CRT. ±Warning: 1 Microphone Cable 2 Disconnect the microphone cable between the microphone and the analog board. If necessary, cut the tiewrap that secures the microphone cable to the degauss coil.
Take Apart Microphone Assembly - 33 3 Microphone Assembly Open the two plastic latches and remove the microphone assembly from the bezel. Replacement Note: You may need to use a flat-blade screwdriver to press the microphone gasket back into the chassis.
Take Apart CRT - 34 CRT CRT Before you begin, • Remove the rear housing • Discharge the CRT • Remove the anode cap • Remove the analog board • Disconnect the microphone cable This product contains high voltage and a high-vacuum picture tube. To prevent injury, review CRT safety and discharge instructions in Bulletins/ Safety.
Take Apart CRT - 35 Never use a grounding wriststrap until after discharging the CRT. ±Warning: 1 2 Remove the four selfthreading screws that secure the CRT to the bezel. Never touch the anode or grasp the neck of the CRT to remove it from the bezel. The neck of the CRT breaks easily and the anode may retain high voltages.
Take Apart CRT - 36 CRT facedown on the protective workbench pad. If you need to dispose of the CRT, refer to CRT disposal instructions in Bulletins/Safety. ±Warning: Replacement Note: If you are replacing a defective CRT, first remove the degauss coil (see the next topic).
Take Apart Degauss Coil - 37 Degauss Coil Before you begin, • Remove the rear housing • Discharge the CRT • Remove the anode cap • Remove the analog board • Disconnect the microphone cable • Remove the CRT This product contains high voltage and a high-vacuum picture tube. To prevent injury, review CRT safety and discharge instructions in Bulletins/ Safety.
Take Apart Degauss Coil - 38 Never use a grounding wriststrap until after discharging the CRT. ±Warning: Ground Strap 1 2 Remove the degauss coil cable from the tie-wrap at the side of the CRT yoke. Lift the degauss coil with attached brackets over the neck of the CRT. Replacement Note: When replacing the degauss coil, be sure to reattach the ground strap to the degauss bracket.
Take Apart Bezel - 39 Bezel Bezel To remove the bezel, • Remove the rear housing • Discharge the CRT • Remove the anode cap • Remove the analog board • Remove the chassis • Remove the microphone assembly • Remove the CRT
Take Apart Fan - 40 Fan Before you begin, remove the rear housing.
Take Apart Fan - 41 Open the two latches and pull the fan straight out of the rear housing.
K Service Source Upgrades Macintosh Color Classic II/ Performa 275
Upgrades VRAM SIMM VRAM Upgrade - 1 VRAM Upgrade Before you begin, remove the logic board. Caution: Review the ESD precautions in Bulletins/ Safety.
Upgrades VRAM Upgrade - 2 Note: The Color Classic II/ Performa 275 has 256K of video RAM (VRAM) soldered on the logic board. You can increase the amount of VRAM to 512K by installing a 256K VRAM SIMM in the SIMM slot (connector J9). Use only 100 ns or faster VRAM SIMMs.
Upgrades VRAM Upgrade - 3 1 J9 SIMM Slot VRAM SIMM 2 Grasp the VRAM SIMM by its edges with the contacts pointing down. Insert the SIMM at an angle into SIMM slot J9. Push back on the SIMM until it snaps into place.
Upgrades Math Coprocessor - 4 Math Coprocessor Before you begin, remove the logic board. Caution: Review the ESD precautions in Bulletins/ Safety. Math Coprocessor You can add a Motorola 68882 math coprocessor to the logic board in the Color Classic II/Performa 275, thereby increasing overall system performance.
Upgrades Math Coprocessor - 5 1 Math Coprocessor J13 Connector 2 Beveled Edge Position the math coprocessor over socket U9 with the beveled edge of the chip toward the large contact connector (J13) at the front of the board. Align the pins in the socket and gently press down the chip.
Upgrades RAM SIMMs Memory Upgrade - 6 Memory Upgrade Before you begin, remove the logic board. Caution: Review the ESD precautions in Bulletins/ Safety. Note: The Color Classic II/ Performa 275 has 4 MB of RAM soldered on the logic board which can be expanded to 10 MB of RAM. The Color Classic II/ Performa 275 includes one SIMM expansion slot with two 30-pin connectors.
Upgrades Memory Upgrade - 7 system requires 100 ns or faster RAM SIMMs. For additional information, refer to Hardware/Memory. 1 RAM SIMM J10 SIMM Connectors Note: Both connectors in the J10 SIMM slot must be filled or both must be empty; you cannot install a SIMM into just one of the two slots. Grasp the RAM SIMMs by the edges with the contacts pointing down. Insert the SIMMs at an angle into the J10 connectors.
Upgrades Memory Upgrade - 8 2 Push back on the SIMMs until they snap into place.
Upgrades PDS Upgrades - 9 PDS Upgrades Before you begin, remove the logic board. Note: The 96-pin processor direct slot in the Color Classic II/Performa 275 is compatible with the PDS slot in the Macintosh LC. Currently Apple offers two PDS expansion cards for the Macintosh LC and Color Classic series: the Apple IIe emulation card and the LC Ethernet card.
Upgrades PDS Upgrades - 10 Caution: Review the ESD precautions in Bulletins/ Safety. Rear Housing 1 2 Lock Plate Squeeze together the latches and pull the lock plate off the inside of the access cover. Remove the access cover from the rear housing.
Upgrades PDS Upgrades - 11 3 J8 PDS Connector Connect the expansion card to the 96-pin PDS connector (J8) on the logic board.
K Service Source Additional Procedures Macintosh Color Classic II/ Performa 275
Additional Procedures Battery Verification - 1 Battery Verification Before you begin, remove the logic board. If handled or discarded improperly, the lithium battery in the computer could explode. Review battery handling and disposal instructions in Bulletins/Safety. ±Warning: Battery Caution: Review the ESD precautions in Bulletins/ Safety.
Additional Procedures Battery Verification - 2 1 2 Negative Probe Positive Probe 3 Set the voltmeter to the 10 volts DC scale. Hold the positive probe of the voltmeter to the positive end of the battery and the negative probe to the negative end of the battery. If the battery voltage is below 3.0 volts, replace the battery. Refer to “Battery Replacement” in this chapter.
Additional Procedures Battery Replacement - 3 Battery Replacement Before you begin, remove the logic board. If handled or discarded improperly, the lithium battery in the computer could explode. Review battery handling and disposal instructions in Bulletins/Safety. ±Warning: Battery Caution: Review the ESD precautions in Bulletins/ Safety.
Additional Procedures Battery Replacement - 4 1 Cover 2 Battery Holder Insert a small flatblade screwdriver into the top of the battery holder cover and gently push down and out with the screwdriver to release the tab. Repeat on the other end and remove the cover from the battery holder.
Additional Procedures Battery Replacement - 5 3 4 Grasp the battery and remove it from the holder. Return the battery to Apple for proper disposal. For battery packaging and labeling information, refer to the instructions in Bulletins/Safety.
K Service Source Adjustments Macintosh Color Classic II/ Performa 275
Adjustments Geometry - 1 Geometry Before you begin, remove the rear housing. This product contains high voltage and a high-vacuum picture tube. To prevent injury, review the CRT safety instructions in Bulletins/Safety.
Adjustments Geometry - 2 Note: The controls on this monitor require a short hex-head plastic tool to make adjustments. If the tool is long or too thin, it will be too flexible, which will make fine adjustments difficult. Use a short, rigid, hex-head plastic tool to minimize flexing. Warning: Do not use metal alignment tools—they are a shock hazard.
Adjustments Geometry - 3 board. Before switching on system power, make sure the chassis is not touching the logic board. To prevent the bottom of the chassis from buckling and touching the logic board, you may want to support the rear corners of the chassis. All-White Screen 2 Switch on system power. Using Display Service Utility from the Utilities folder of the MacTest Pro CD, display the AllWhite Screen test pattern.
Adjustments Geometry - 4 Vertical Center All-White Screen Vertical Center Using a hex-head plastic adjustment tool, adjust the vertical center control until the raster is centered (top to bottom) in the display area.
Adjustments Geometry - 5 Horizontal Center All-White Screen Horizontal Center Using a hex-head plastic adjustment tool, adjust the horizontal center control until the raster is centered (side to side) in the display area.
Adjustments Geometry - 6 Vertical Size 1 All-White Screen 2 Vertical Height Using a hex-head plastic adjustment tool, adjust the vertical height control until the raster height is 4.9 inches (± 1/16 inch) or 124.5 mm (± 1.5 mm). Verify this height. If it is off, repeat the vertical size adjustment and, if necessary, the vertical center adjustment.
Adjustments Geometry - 7 Horizontal Size All-White Screen Horizontal Width Using a hex-head plastic adjustment tool, adjust the horizontal width control until the raster is 6.7 inches (± 1/16 inch) or 168.5 mm (± 1.5 mm).
Adjustments Geometry - 8 Focus 1 Focus Focus 2 Using Display Service Utility, display the Focus test pattern. Using a hex-head plastic adjustment tool, adjust the focus control until the Focus test pattern is as clear as possible.
Adjustments Video - 9 Video Before you begin, remove the rear housing. This product contains high voltage and a high-vacuum picture tube. To prevent injury, review CRT safety and discharge instructions in Bulletins/ Safety.
Adjustments Video - 10 Caution: With the rear housing removed, the metal chassis could short to the bottom of the logic board. Before switching on system power, make sure the chassis is not touching the logic board. To prevent the bottom of the chassis from buckling and touching the logic board, you may want to support the rear corners of the chassis. Replacement Note: Perform the cutoff video adjustment whenever you replace the analog board.
Adjustments Video - 11 Cutoff Gray Bars Bezel Contrast Note: Perform the cutoff video adjustment prior to adjusting white balance. Switch on the system at least 10 minutes prior to performing these adjustments. 1 2 Using Display Service Utility, display the Gray Bars test pattern. Press the contrast up button and set screen contrast to maximum.
Adjustments Video - 12 3 4 Red Background Green Background Blue Background Select the Brightness Control Panel from the Apple menu. Drag the brightness control to midrange. Using a hex-head plastic adjustment tool, set the red, green and blue background controls to the full counterclockwise positions.
Adjustments Video - 13 5 6 Sub-Contrast Green Drive Blue Drive Set the green and blue drive controls to their 3/4 position by turning the controls to their full clockwise position and then turning back 1/4 turn counterclockwise. Set the sub-contrast control to its full clockwise position.
Adjustments Video - 14 7 Gray Bars 8 G2 Sub-Contrast Using a hex-head plastic adjustment tool, adjust G2 until the first bar in the test pattern is completely black and the second bar is barely discernible. Set the sub-contrast control to the center position.
Adjustments Video - 15 White Balance Gray Bars Bezel Contrast Note: Before adjusting white balance, perform the cutoff video adjustment. Make sure that • The Gray Bars test pattern is displayed. • Contrast is set to maximum. • Brightness is set to midrange.
Adjustments Video - 16 1 2 Gray Bars Red Background Green Background Blue Background Note the predominant color. Using a hex-head plastic adjustment tool, alternately adjust the red, green, and blue background controls until there is no predominant color in the four darkest bars. Note: The darkest bar must remain completely black throughout the rest of the procedure.
Adjustments Video - 17 appropriate background control. 3 Gray Bars Green Drive Blue Drive If necessary, adjust the blue and green drive controls until there is no predominant color in the four brightest bars.
Adjustments Video - 18 4 Gray Bars Red Background Green Background Blue Background Check the four darkest bars. If necessary, adjust the red, green and blue background controls until there is no predominant color.
Adjustments Video - 19 5 All-White Screen Sub-Contrast 6 Using Display Service Utility, display the AllWhite Screen test pattern.
Adjustments Video - 20 Important: Over time, light tolerances can vary. If you doubt your meter’s accuracy, verify the readings with a known-good light meter or photometer.
Adjustments Convergence - 21 Convergence Before you begin, remove the rear housing. This product contains high voltage and a high-vacuum picture tube. To prevent injury, review CRT safety and discharge instructions in Bulletins/ Safety. ±Warning: Convergence Controls 1 Logic Board Chassis Warning: High Voltage Areas Support Caution: With the rear housing removed, the metal chassis could short to the bottom of the logic board.
Adjustments Convergence - 22 sure the chassis is not touching the logic board. To prevent the bottom of the chassis from buckling and touching the logic board, you may want to support the rear corners of the chassis. Crosshatch I 2 3 Convergence Control Switch on system power. Using Display Service Utility, display the Crosshatch I test pattern.
Adjustments N/S Correction Control E/W Correction Control Convergence - 23 4 Crosshatch I E/W Amp Control 5 for best overall convergence. Using a hex-head plastic adjustment tool, adjust the N/S correction control for best convergence of horizontal lines at the top and bottom of the screen. Adjust the E/W correction control for best convergence of vertical lines at the left and right sides of the screen.
Adjustments Convergence - 24 6 Adjust the E/W amp control for best convergence of horizontal lines at the left and right sides of the screen.
Adjustments Geometric Distortion - 25 Geometric Distortion Before you begin, remove the rear housing. This product contains high voltage and a high-vacuum picture tube. To prevent injury, review CRT safety and discharge instructions in Bulletins/ Safety.
Adjustments Geometric Distortion - 26 Caution: With the rear housing removed, the metal chassis could short to the bottom of the logic board. Before switching on system power, make sure the chassis is not touching the logic board. To prevent the bottom of the chassis from buckling and touching the logic board, you may want to support the rear corners of the chassis.
Adjustments Horizontal Bow (PB) Pin Phase (KS) Vertical Angle (PR) Geometric Distortion - 27 Note: Perform the following geometric adjustments to correct distortions other than geometric center, size, and focus problems (see “Geometry”). ±Warning: The entire yoke assembly has very high voltage. To prevent electrical shock, do not touch the yoke assembly, the anode wire, or the yoke wires. 1 To determine which control to adjust, compare the display with the distortions shown.
Adjustments Geometric Distortion - 28 2 3 Pin Phase Horizontal Bow Vertical Angle Using a hex-head plastic adjustment tool, adjust the control that is appropriate for the distortion.
Adjustments Geometric Distortion - 29 4 5 Analog Board If the display is still distorted, repeat the vertical angle and pin phase adjustments. If you can’t correct the distortion, replace the analog board. See “Analog Board” in the Take Apart chapter.
Adjustments Yoke - 30 Yoke Before you begin, remove the rear housing. This product contains high voltage and a high-vacuum picture tube. To prevent injury, review CRT safety and discharge instructions in Bulletins/ Safety. Plastic Yoke Collar ±Warning: Yoke Clamp Screw Because you must make yoke adjustments from the rear of the computer, use a mirror to view the computer screen.
Adjustments Yoke - 31 Do not reach around the computer to adjust collars and rings. Yoke Clamp Screw Replacement Note: If you replace the CRT, you will probably have to adjust the yoke. 1 2 Using an insulated cross-tip screwdriver, loosen the yoke clamp screw two or three turns.
Adjustments Yoke - 32 board. Before switching on system power, make sure the chassis is not touching the logic board. To prevent the bottom of the chassis from buckling and touching the logic board, you may want to support the rear corners of the chassis. Plastic Yoke Collar 3 Switch on the computer.
Adjustments Yoke - 33 Plastic Yoke Collar Yoke Clamp Screw 4 5 6 7 the top and bottom of the bezel. Switch off and unplug the computer. Discharge the CRT. Hold the plastic yoke collar in position and carefully tighten the yoke clamp screw so that the collar cannot slip. Do not overtighten the screw. Replace the rear housing and switch on the computer.
Adjustments Yoke - 34 8 Verify that the top and bottom edges of the picture are parallel with the top and bottom of the bezel.
Adjustments Light Meter Setup - 35 Light Meter Setup This topic covers setup for three light meter models: R77, L-248, and 246. Model R77 (Apple part number 076-0310) is the newest model available. Model R77 The R77 light meter is capable of reading luminance from 10 to 1,000 footcandles (fc).
Adjustments Light Meter Setup - 36 from the lens. Three scales are shown on the light meter: • 200-1000 fc • 50-250 fc • 10-50 fc Because display screen luminance typically ranges from 10 to 50 fc, take readings from the bottom scale only.
Adjustments Light Meter Setup - 37 To measure a display screen’s luminance, 1 2 Set the scale switch to the bottom position (to set up the 10-50 fc scale). Place the lens against the middle of the screen and read the bottom scale. Note: When the light meter is not in use, slide the scale switch to its top position, and store the meter in its protective case.
Adjustments Light Meter Setup - 38 readings, verify the readings with a known-good light meter or photometer. Also check the age of the R77 light meter by its four-digit manufacturing date stamp (such as 0398 for March 1998). Caution: Dropping the meter can permanently damage its accuracy. A shock-damaged meter might read incorrectly or its pointer may not drop to zero.
Adjustments Light Meter Setup - 39 Lens Model L-248 1 Side Switch Read Button 2 3 Red Area Scale 4 Press the red button on the back of the light meter. If the reading is out of the red area, replace the battery. Move the side switch to its upper position so that the scale reads 10 through 18. Uncover the lens of the meter. Place the lens against the middle of the screen and press the read button to read the scale.
Adjustments Light Meter Setup - 40 Model 246 Lens Swivel Head 1 2 3 Scale Remove the metal slide, if installed, from the top of the light meter. Install the white lens with the red dot. Rotate the swivel head so the lens of the meter faces the monitor. Place the lens against the middle of the screen and read the scale.
K Service Source Exploded View Macintosh Color Classic II/ Performa 275
Exploded View 1 Exploded View CRT 661-0004 661-0024 (Australia) 661-0022 (Europe) Internal Microphone 922-1802 Degauss Bracket 922-1818 Degauss Coil 922-1816 Rear Housing 922-1814 Front Bezel 922-1811 Name Plate 922-1813 Fan 922-1803 Screw (4) Screw (4) Analog Board/ Power Supply 661-0732 Floppy Drive 661-0474 I/O Door 922-1815 Access Cover Shield 805-0137 Security Screws Access Cover Rear Case 815-1154 Speaker Assembly 922-1801 Logic Board 661-1830 Floppy Drive Carrier 922-1807 Hard Drive 661-02
