502/Repairs
Supply out of regulation
- Symptom: +350 V supply out of regulation (~300 V)
- Root cause: C751 10 nF "Bumble Bee" leaky
- Solution: Replace C751
HV very low
- Symptom: HV very low, oscillator tube V800 gets very hot
- Root cause: Black Beauty capacitors in HV circuit leaky
- Solution: Replace all 6.8 nF HV caps
No sweep at slower speeds
- Symptom: In 1 ms/Div and slower, no sweep − trace stationary on left
- Root cause: Bumble Bee capacitors in holdoff circuit leaky
- Solution: Replace C180B-D