Problem Centipede Cocktail High Pitched Whine

[eccentric-nut]

Hi,

Long story short, Looks like I have just sold my Atari Centipede cocktail, it had been moved recently and then put into storage, I have just powered on to test, and all seems well game plays fine, except now it has a noticable high pitched whine, after a bit of logical deduction it is coming from the games PCB, it is not from the CRT screen as I disconnected the CRT screen's power with the game running and the whine is still present.

Power supply has already been rebuilt by myself in the last three years, including replacment of the big blue.

Any ideas what could be causing it on the PCB and where to begin trouble shooting?

My hearing is good, but sadly not good enough to pinpoint exactly where it is comming from on the PCB.

Cheers.

 

[BigP_BigP]

A few ifs and buts in this reply.
Its highly likely its either coil whine (from memory there is a blue inductor at the back of the pcb, but its a shady memory) or cap squeal.
Two things to determine, 1- is it a new noise or has it always been there? 2 - does it change pitch under different loads.
If its new and dosent change pitch under load its likely cap squeal.
If it always been there and does change pitch under load its likely coil whine.
Coil whine is annoying but typically not a sign of a fatal problem.
Cap squeal on the other hand is likely a sign that one or more of the caps is either leaking or close to leaking.

Also check that its not coming from the PSU because coil whine on older PSUs is pretty typical. Hope this helps.

 

[eccentric-nut]

Thanks for the tips, very sure it is a new noise as I certainly do not remember it at all being present before.

Going to do a full check of the AR board over the weekend, however the caps on those are nearly alway still in excellent condition, then I will move onto the game PCB.