star wars amplifone went out....again

Mcc313

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I had had this same problem before. it's been about 8 months since I had it repaired. I'm sure this is common with these. my guess is Q6 and Q7 fried? smoked some resistors too. R7, R3, and C2 look burnt. any idea what could of went wrong? I don't want to change all of the fried parts for it to happen again.

 
It's hard to know exactly which parts are fried just from looking at it. You will need to replace all obviously burned parts, then test all of the transistors, including the ones that are bolted to the large heatsink (all 8 of them, the big ones and the small ones). Google how to test a transistor with a DMM.

Also, you only need to post in one forum. (Monitors forum in this case.)
 
ok i will do that. i just replaced the transistors on the heat sync less than a year ago. thanks.
 
look at the schematic and see what those resistors feed. I'm guessing the u57 or u07. Also check the bottle caps for that channel as well.
 
If you are changing values by using the diagram of the deflection board with the printed values, you are in for a rude surprise. That page is full of mistakes.

R8,13,31,36 are 3.3 ohm not 3.3K ohm

R7,12,30,25 should be 10 ohm not 10K ohm. Although I have found 15 ohm factory resistors in those locations. Check all your transistors. What's with the red wire to the resistor?
 
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