68kMLA Classic Interface
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| Click here to select a new forum. | | TDK LC supply still clicking after recap | Posted by: Bolacore on 2019-12-05 12:00:31
I recently picked up an LC that had a TDK power supply with lots of leaky caps. When powered on one of the big TO220 diodes would get red hot. The back side of the power supply is all black as well, presumably from being run when shorted. I've replaced all the caps, resoldered all the joints on the low voltage side, and now it longer heats up, but just clicks.
If I put the output on a scope it rises and falls with the clicks, but all 3 rails hit the right voltage before the click. Does it once every 1.5s or so. Under load it does it every ~1s and the output sags down to a couple volts. Not really sure what else to replace on this, as I can't find any schematics for it. Any ideas on what to try next?
| Posted by: LaPorta on 2019-12-06 06:51:18
I forget the proper name (brain fart), but the little cutoff switch that prevents over-voltage may be damaged and Cutting off the flow inappropriately.
| Posted by: techknight on 2019-12-10 08:27:59
@LaPorta Definite brain fart ol buddy...
Check the opto-isolators.
| Posted by: ravuya on 2019-12-22 15:20:54
Is the LC motherboard itself shorted?
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