Aztec LC PSU still ticking after recap

[CompuNurd]

I just recapped an Aztec PSU from a Mac LC, and when I go to turn it on, it just ticks. The solder connections look fine, is there something I am missing?

The voltages I am getting are: ~4.5 from the blue wire, ~1.25 from the yellow wire, and ~.60 from the orange wire.

 

[360alaska]

Are you plugging it into the board when your testing it? It must be connected to the logic board?

 

[techknight]

That. and make sure none of your rails are shorted to ground. 

Last thing is the optocoupler. 

 

[CompuNurd]

Are you plugging it into the board when your testing it? It must be connected to the logic board?

Yes

That. and make sure none of your rails are shorted to ground. 

Hmm. All colored wires show continuity with the two black wires. I don't see a solder bridge anywhere....

 

[techknight]

umm put it on diode check. Red lead on all the rails, 1 by 1, black lead to black. 

What are you readings? 

 

[CompuNurd]

What's it supposed to read? My meter has the diode and 2Kohm functions together. When I measure, the reading is ~.200 then rises up to ~1.700, and keeps going.

 

[techknight]

Then there are no shorts on the rails. 

So, as long as the power supply is connected to a load, it should run. You may need to change the opto-coupler. 

 

[CompuNurd]

I have tested the optocoupler and it seems to be fine (unless I tested it wrong?).

I guess it never hurts to try. The model is CNX82A, Mouser and Digikey do not stock it, but I found some on eBay.

 

[CompuNurd]

The optocoupler seemed to fix it, but there was a humming, presumably from the transformer, and a lifted pad. I don't trust it, so I will be scrapping it.

 

[techknight]

humming is normal, as long as its soft/subtle, thats the analogous sound of the power supply regulating itself. 

 

[CompuNurd]

It was audible from several feet away. If you want it, I'll send it to you for the cost of shipping, shoot me a PM. Better someone make use of it than it being trashed.