Ben,
Thank you for the word of caution concerning the capacitors. I do make
sure that the capacitors are discharged whenever soldering them out before
testing.
Robert,
The reason I asked for schematic diagrams is because I don't understand the
way it works. I understand AC transformers and power regulators but a
computer power supply surprisingly baffled me. I will try to explain.
The flow of current is pretty straight forward in the power supply
travelling from the left side (input voltage 110/220 VAC) of the circuit
board to the right side (output voltage Gnd/-12V/-5V/5V/12V). In the
middle is the transformer. To the right are regulator ICs that produce the
different DC voltages. What baffles me are the bunch of capacitor / filter
circuitry on the left side of the transformer. It seems to filter the AC
line voltage then bridges it to produce a DC voltage (this is the part I
don't understand) **before** the primary side of the transformer. How does
the transformer then work with a DC input? How does it produce the
magnetic flux? I noticed that the multi voltage outputs secondary) of the
tranformer are all also DC voltages. It doesn't make sense to me at all.
That's why I was wondering if anyone has a schematics so I can try to
understand what's going on.
BTW, I also took apart a good desktop computer power supply and came out
with the same findings. The input before the transformer is already DC
voltage. Can someone explain this to me? ... a schematics would even be
better!
totally confused ... Oliver
>Unload the outputs. Fire it up. See if you have sorta proper voltages on
>the outputs now. If so, replace small electrolytic capacitors in that
>"back end" that has you confused until it will supply a voltage under
>load. If not, replace the +5 and perhaps the +12 output ripple filter
>capacitors (your post tells me you can understand this).
>
>If there are any blown fuses, forget I said anything and consult a tech
>near you. (a REAL one, not the guy at the computer store)
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