Quote:
Originally Posted by zeno
At this point I would see if IC601 is oscillating. Should be large
waveform at primary of T605. IC601 may have been damaged
or defective new. 99% they dead short BUT you never know.
Dont forget this may have been self inflicted so look for things
you dont expect. Dont feel bad it happens to everyone.
So use a scope & ISOLATION TRANSFORMER & get that thing
oscillating............ Then you can fix the real problem.
BTW I had HUGE advantages with a problem like this.
I fixed TV's from 1970 til a few yrs ago. Tens of thousands of
them. We were Sony ASC so I could call Sony. The TV was in
front of me. I could order a board (usually) & return it if need be.
I belonged to a pay site with tips & techs. I had both OEM &
Sams hard copy manuals, PDF manuals SUCK !!! I had training
manuals & went to seminars easily 5 times a year. Top notch
newer test eq. Other techs, if self inflicted this is key.......
Stick with it & let us know how you do
73 Zeno
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Dang that was the good ole days ey
I've been a Guitar Amp Tech for 25 years now but this ain't tube gear although I understand some of it and work on some monitors every now and then so I get the circuit just never worked on a switching supply this complex. But if you guys hang with me I 'll do what you say. TWbranch brought me here and said he had a lot of respect for you all so it's all good.
I'll post what I find. I have an isolation tranny and will scope the transformer. Where should I set the voltage and frequecy sweep and how large voltage wise am I looking at ?
One thing though that the double transistor IC-601 is not shorted and is diode checking pretty well. The last one I took out wasn't shorted either but was mismatched in resistance from trasistor to transistor. This supply was working when I took it out and not sure what went South when I put it back in but that chip is getting way to hot to run for any amount of time. When I find the problem the heat issue will go away I think or maybe it does run that hot. That is a monster heat sink