Sega PSU 400-5149 audio whine/black bars

[Texas_Funnyhair]

Hey there y'all, so took the PSU in my Sega Aero city out to recap it and reflow the connectors. Unfortunately putting it back in though I found that it was now causing an audio whine and some wavy black bars to scroll down the screen with my U.N. Squadron PCB, no sign of those with the Neo Geo board I have in the same cabinet.

Did confirm that the PSU is showing proper voltages at the edge connector ~+5V, ~-5V, ~+12V. I do have another PSU so I swapped that in and and the issue went away. So definitely something I did or a cold solder joint I managed to give a knock. Has anyone run into an issue like this? I'm thinking it might be something introducing a ripple into one of the voltages.

 

[Retro Mecano]

Check this thread out for caps references. Specially the voltage rating and compare it to the one you used. Then check cap orientation, it happened everyone before to mpunt it reversed polarity..
resolder anyway the job you did.

Thread 'Aero City PSU capacitor maps (400-5081, -5149 & -5198)'

Jun 3, 2020

Recapped a few of these the other day. Quite a few caps had started leaking. One actually broke off when I pulled on it leaving a leg behind. So if you have one these in original state, I suggest putting some new caps on it.

Anyway,


400-5081, 400-5149 & 400-5198 (same PSUs basically, components just differently laid out and a different set of connectors)

Input: 90-138VAC
Output: +5V 7A, +12V 1.5A, -5V 0.1A



(400-5081 on top, 400-5149 / 400-5198 at bottom)

Capacitor     Diameter  Qty  Location

0.47uF 50V    5mm       1    C11
3.3uF 50V...

• nem
• Replies: 12
• Forum: Other Sega Hardware

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