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That would certainly work. I use an old RCA Viz model. You can also just get a isolation transformer - the transformer itself, not the whole piece of gear - and wire it up to an outlet on your bench, or put it in a box like the tenma piece. Then again, $100 isn't bad.
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Education is what you're left with after you have forgotten what you have learned. -
Put a cover over it and stand back?Originally posted by lowell View Post
Sorry but SMPSs don't take to variacs or lamp limiters very well.Comment
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Ok so there isn't an "isolate the stage" approach? IE "disconnect or lift this or that first to see if fuse blows. If it doesn't blow, reconnect."
I know these SMPS are so intertwined that they wont really work unless everything is working...but not 100% on that...particularly with this one.Comment
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I had wondered the same thing. The PLX3102 uses exactly the same clamp and component values so my guess is adding the zener would be good insurance here too. The lack of it may be the sole reason for the failure. I guess you will get some indication of that if you find that is the only issue.Originally posted by Jazz P Bass View PostExperience is something you get, just after you really needed it.Comment
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Guess I'll be firing this thing up.....no pun intended.Comment
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Tryin to figure this out. I'll post my progress...hopefully it'll help someone else in the future.
This is pretty informative.
Notes on the Troubleshooting and Repair of Small Switchmode Power Supplies
Seems as I can pull both IGBTs and check related circuitry before installing the new ones.Comment
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And another here (see post #3):
http://music-electronics-forum.com/t23974/Originally posted by Enzo
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I've replaced the PWM, both IGBTs (they both fell apart upon removal, clearly fried), The relay K1, modified per service notes with diode, replaced a couple resistors and diodes that read wrong.
I've powered it on with a bulb limiter. Looks good, bright upon throwing power switch, quickly changes to very low glowing.
Do I just throw it on? I haven't purchased an ISO transformer yet, just can't afford it right now.Last edited by lowell; 01-08-2016, 10:09 PM.Comment
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If you also cant afford a torched amp I'd vote for WAIT but maybe you're the daring type... good luck!Originally posted by lowell View PostComment
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Wait a minute. Won't my variac work as an ISO transformer?Comment
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Ok it is not the same thing. Just read online that a variac shares primary/secondary windings. Well, I don't believe an iso will stop the amp from destructing but simply be a safety precaution. Being that this amp has a plastic power switch and I won't be touching it, and will have the lid on, I think I'll just fire it up.
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No. Variacs are usually auto-transformers. The point of the isolating transformer it to allow you to probe the SMPS to use test equipment such as a scope to debug it. Seems that you've have already fired it up with the light bulb limiter. Now since this thing is on one big board doesn't that mean that you already powered the entire system? Did you check the PSU output voltages? If they are OK I think you'd be good to test it without the bulb limiter.Originally posted by lowell View PostExperience is something you get, just after you really needed it.Comment
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I tried but I get no readings. I think it's one of those SMPS that doesn't startup with a limiter.Comment
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Threw it on. Nothing. Main fuse is good. I read that it could be an open startup resistor. Anyone know where that is in this pic?
Screen Shot 2016-01-09 at 1.45.00 PM.PDFComment
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Originally posted by lowell View Post
The startup is internal to the TOP210. It is a flyback converter that drives T1. Once that is happening then +16V is supplied to the rest of the PSU. Check D62 cathode for 18V.Experience is something you get, just after you really needed it.Comment
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