Hantarex US250 whining under load

mourix

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My Electrocoin 6-slot neo geo didn't like being stored in an unheated shed for many years. Since putting it away I've repaired the MV6 motherboard to a point where it's playing with half the slots. The Hantarex US 250 power supply didn't work when I plugged it in. It only made a high pitched sound and the monitor didn't even get power.

After reading info on this forum I reflowed all the solder joints on the PSU. After this it was silent and perfectly regulating without load. However when I connected the Neo Geo pcb however it booted up but the US250 supply still made this high pitched sound that rarely goes away.

Yesterday I replaced all the capacitors but the big one with Nippon 105C low esr ones. When I plugged it in today the problem remained the same: a working arcade game with a screaming power supply.

I'm a bit stuck here. Can anyone give me some advice on how to proceed?

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