MTX Thunder 4202 Question

[midnightg35x 10+ year member]

Does anyone have one of these amps they would be willing to open the case up to find 4 component values for me? I am looking at repairing one, but 4 resistors have been burnt with no visible markings and they all measure as open when I removed them. The resistors are labeled R628, R636, R629, R637. They are right next to one of the main power supply capacitors. If anyone can help me out, that would be great!

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[infamous_e46 5,000+ posts]

ampjunkie might know

 

[Grinder1989 5,000+ posts]

Chances are that there is more damage than the resistors. Just because a part doesn't look bad, doesn't mean it isn't bad.

 

[midnightg35x 10+ year member]

Chances are that there is more damage than the resistors. Just because a part doesn't look bad, doesn't mean it isn't bad.

Yea, the power supply FET's are blown also. I can read the labels off those though //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Those resistors all test open and looked slightly burnt. I would assume they were the resistors associated with the power supply. There was no label on the resistors, so finding their values is tricky. The output FET's all tested fine.

I design and test amps (RF, not audio) for a living, so I can certainly relate to what you're saying about a part looking/not looking bad.