Ac voltage at controlled lamps

[steph300]

I have a stern big game with about 15 flickering lamps (incandescent). Leds do the same thing.

Those flickering controlled lamps have a dc voltage fluctuating about 5 times a second front 2v dc to 5.6v dc. The normal working ones are steady 5.6v.

I decided to measure ac voltage, and on the normal light, it's at 0.3v ac.

The flickering lights (controlled) have 3.2v ac.

Why do I have so much ac voltage at controlled lamps...

 

[MrMikeman]

My guess would be a crappy capacitor on the rectifier board.

 

[steph300]

New caps (c23, c24, c26) were just installed on the solenoid board.

 

[sylvain]

Assuming you already checked the DC voltage from the power-supply for the controlled lamps,
issue could be on the MPU board on the zero-crossing detector circuit, e.g. U14 and signals/components around it.
Good luck!

 

[steph300]

I found a fix!

Seems my alltek mpu needed a vintage cd4049 (u12) for big game and stars. Other game I testing in like seawitch was fine. Odd indeed. I had also tried 3 other new cd4049ube but only a vintage one fixed it.