ZX750.1 up in flames.

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Ok I went over the board with a magnified lamp and the only thing I found was a possible bad connection on a blue rectangle close to 4 capacitors marked 105K100, I resoldered it, should I put the rectifiers back in and try it or should I wait. My dad mentioned my grandfather had an old scope in the basement would that possibly work? Im not sure how old it may be.
 
amp pic

Ok heres a pic of the component. Its the little blue rectangle.

As far as the scope goes Ill try to get more info.
 

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Post a photo of the front panel of the scope you have after confirming that it works.

That scope would do everything that you'd need for most all repairs. Do a completed item search to see what they sell for. I'd expect it to sell for over $200.

As a side note, that's a TAS475. It's much different than the older 475.
 
Ok I installed the rectifiers and removed the outputs and lo and behold 2 shorted outputs, How did I miss that? Is it because I checked them in circuit? or did I make a rookie mistake?

I lost the bid on the scope, Im still on the hunt, is there anything specific I should be looking in for a scope?
 
Did you check them properly? If you don't discharge the gate/source, they may appear shorted. The following page has a section for testing FETs:
Basic Amplifier Repair - Transistor Test Applet Link

A simple analog scope is all you need. Either post auction numbers or email me directly. The used BK Precision 2120B scopes go for about $150 and at that price, they're a good deal.
 
All three pins of one irf9640 and one irf640 and a dead short. Boards all cleaned up ready to go. Now on to the KX2500 with the same problem.

Ill purchase a scope when payday comes, I plan on repairing more amps, I figure after repairing a few that I should start progressing in the troubleshooting department.
 
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