Service manual

East/West Drive.
At pin 3, the E/W-drive is available. Pin 4 is a feedback input for the EHT-info and is
used to prevent pumping of the picture. EHT varies also dependent of the beam current.
Frame Rotation.
For frame rotation, a control voltage is used from pin 25 of the HOP. This voltage can
vary from 0.4V to 4V.
Guarding Protections:
Flash detection:
When a flash occurs, the EHT-info will become negative very fast. Via
D6303/D6304/R3316, TS7303 starts to conduct. This makes pin 5 of HOP high. When
pin 5 of HOP is high, then the output (pin 8) is immediately stopped. If the H-drive stops,
then also pin 5 will be low again, which will reset the flash detection. A bit (FLS) will be
set in an output status register, so via the Painter it can be seen when there was a flash.
This FLS-bit will be reset when the Painter has read that register.
HFB protection:
If the HFB is not present then this will be detected via the HOP. The Painter puts the TV
into protection and an error code will be generated.