RF punch 125.2 problem

[chrisw91 10+ year member]

i bought one of them from the local flea market for $10 and figured it would be worth it even if it wasnt working. so it powers up fine. but when i went to power it up with speakers connected it blew my fuse in the distro block. so a short? nothing on the board is burnt. whats going on here?

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[Spooney 10+ year member]

probably has some shorted or leaky output transistors. Just because nothing looks burnt doesn't mean a component can't be defective. I've seen tons of blown fets that looked perfect. If you have a multimeter you could set it to the lowest resistance range and check between the three legs of each output transistor(usually found near the large resistors on the rca end of the amp). If you are getting very low resistance readings between any of the three legs of each output transistor then you most definitely have some bad outputs. if you find the amp to be bad and don't want to mess with it PM me and I would probably buy it from you.

 

[chrisw91 10+ year member]

well i see there are a bunch of transistor on both sides of the amp that are glue to separate boards, but soldered to the main door. is that them? i got a bunch of different readings from them. some had k ohms and others were down to single digits. what is spec on these things?

 

[Spooney 10+ year member]

I'd really need to see a pic of what transistors you probed to be able to help you properly. You should have been testing the fets on the outermost edge of the amp and probably looking for the 4-8 fets that are closest to the rca input end of the amp near some large resistors( most likely green with colored bands). Are your fets attached to another little green board on the backside of them? sounds like your amp has the mehsa system which can be a pain to work on especially if you have never done anything like this. Without knowing exactly where you tested the ohm readings you gave me are basically useless.