QUOTE(JFreezus @ Mar 31 2010, 11:54 PM)
where to start....first off there's a transformer in the psu the converts 120 to something like 26v....that might need replacing....
A SMPS doesn't work that way, that's how a Linear PSU works.
I am a professional technician and even I wouldn't start trying to fix a power supply that I did not have a schematic for and the engineer who designed it with me there.
That's a contradictory statement, if you were a professional technician you wouldn't really need a schematic to troubleshoot the preregulator stage of an SMPS, and if you did you'd just make one up for it or the circuit in question as you go thru it, that's what I do.
@ linsonchan - With all of the different versions of PSUs that are out now, as well as multiple versions of each one of those, it's still not worth it to get in there and go messing around unless you know what you're doing and have the time/money to spend on tinkering with it That's provided you can even find replacements for some of those components as that's one of the main hurdles you'll run into when repairing things now, there's no way to cross reference some parts, or you'll find very little documentation on them. So you're left with knowing what the part pretty much is, but can't get the specifics on it, and while tossing in some generic replacement in a Linear PSU isn't going to fry it up like an egg, with an SMPS that's just asking for something to blow up in your face when it's plugged back in.
No one here is trying to talk you out of learning something new, but an SMPS really is not a good place to start out, because of the complexity of it as well as the danger in working on one.This post has been edited by RDC: Apr 1 2010, 11:19 AM