cheesestraws
Well-known member
Another slightly odd one for people's information.
Symptom: SE AB with badly-adjusted height image: while adjusting the potentiometer the screen collapsed to a single line in the middle of the screen and turning the pot had no effect.
Cause: Turned out that the height potentiometer itself had failed—the analogue board must have had a hard life. It took very close examination to see it, but there was a hairline crack all the way across the substrate, and it was reading open circuit. On desoldering it, it fell in half. A new potentiometer was installed and it's working fine now.
Symptom: SE AB with badly-adjusted height image: while adjusting the potentiometer the screen collapsed to a single line in the middle of the screen and turning the pot had no effect.
Cause: Turned out that the height potentiometer itself had failed—the analogue board must have had a hard life. It took very close examination to see it, but there was a hairline crack all the way across the substrate, and it was reading open circuit. On desoldering it, it fell in half. A new potentiometer was installed and it's working fine now.
