Service manual

Madrigal Audio Laboratories
P.O. Box 781
Middletown, CT 06457-0781
[phone]
FAX [phone]
TECHNICAL SERVICES
INFORMATION SHEET
PX-600 SRAM R
EPLACEMENT
DECEMBER 8, 1999 Page 1 of 2
PX-600 SRAM Replacement.doc Page 1
DOC# AA12899 WB-DW / FB-DW
O VERVIEW
This procedure will guide you through the steps needed to replace the SRAM in the PX-600. Read the procedure
carefully before beginning the SRAM replacement.
I NSTALLING THE SRAM
WARNING:
Follow Anti-static Procedures!
A static-free workspace with conductive mat and wrist-strap or equivalent precautions must be used to protect static
sensitive parts on the control board from damage. Before touching any of the boards inside the MRX, if you're not
using the mat and wriststrap, discharge any static you may be carrying by touching something metal, preferably
something that is grounded like the wallplate screw on a grounded electrical box. You should re-ground yourself often
throughout the procedure and certainly whenever you are about to handle a board, or when you have walked away
momentarily and come back.
What is Needed
 Philips Screwdriver
Procedure
1. Turn OFF the PX-600 main power on the rear panel and disconnect the AC cord.
2. Remove the top cover of the PX-600.
3. Carefully remove the IC at location U804.
This is next to the EPROM (Vx.xx). It can be found on the mid left side of the printed circuit board when
looking downward from the front of the unit.
Note that the correct SRAM should be Benchmarq BQ 4011. If a Benchmarq BQ 4010 is installed in
this location, it should be replaced with the BQ 4011.
4. With the FRONT of the PX-600 towards you, Carefully place the new SRAM into the socket with the dimple
on top of the IC in the upper right hand corner and give a slight push down to ensure the SRAM is properly
seated in the socket.
There is a dimple on the IC designating pin 1 as well as a notch designating the front end of the IC. The notch
is also visible on the IC socket and on the PCB silk-screen. And give a slight push down to ensure the SRAM
is properly seated in the socket.
5. Replace the top cover with the original screws.
6. Hook up the programmer and power up the PX-600 from the main power switch on the back panel.
7. Go to the main programming menu and choose TEST MENU, scroll to DATA RESET and press ENTER.
8. This will clear the memory of all IR codes and reset the controller to factory default settings.
9. You are now ready to configure the system to your client’s needs. After you have finished programming,
check each zone for correct operation. If you have questions please contact our Customer Support
Department at the above numbers.