Ive got this amp here with one of two channels blown. I clipped all FETs which all shorted i nthe bad channel, and the amp powered up and plays out of the good channel.
The output transistors are FQA36P15 and FQA46N15. I tried a few places and it looks like theres a few mis-matched parts available from different resellers. Arrow has the Fairchild FQA46N15 which is fine (and good price). They are out of stock on the FQA36P15 and no place seems to be selling the FQA36P15. Digikey comes close with an IXYS brand, IXTQ36P15P but they are pretty expensive and IXYS does not seem to have their branded counter-part.
Is there some other, better fet or retailer I can get replacement or substitute fets for this and other style, newer RF amps?
The output transistors are FQA36P15 and FQA46N15. I tried a few places and it looks like theres a few mis-matched parts available from different resellers. Arrow has the Fairchild FQA46N15 which is fine (and good price). They are out of stock on the FQA36P15 and no place seems to be selling the FQA36P15. Digikey comes close with an IXYS brand, IXTQ36P15P but they are pretty expensive and IXYS does not seem to have their branded counter-part.
Is there some other, better fet or retailer I can get replacement or substitute fets for this and other style, newer RF amps?
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I got the right outputs and installed, "FQA36P15" and "FQA46N15" into Q1024, Q1025, Q1026, and Q1027. now when the amp powers up, it draws my power supply down to protection and the cycles power about every 2 seconds. Previously, I had clipped 3 out of these 4 outputs, and the one which survived was playing 1/2 the waveform on the scope.
OK I did find R1065 which is a 0.10 ohm resistor totally open. I replaced all four in the amp but it still experiences the problem.
I turned the bias pot fully counter clockwise and the problem still happens. While the amp is power cycling, the voltage accross the source resistors is ~0.040 in the bad channel. Too high. 0.001 in the good channel.
I turned the bias pot fully counter clockwise and the problem still happens. While the amp is power cycling, the voltage accross the source resistors is ~0.040 in the bad channel. Too high. 0.001 in the good channel.
Rockford 500.2 Amp with same problem
I just replaced the MOSFET for the bad channel and the amp gets hot on that channel fast and draws significant current, but the potentiometer does not change anything. Fosgate is very secretive and will not help with schematic or advise. They only refer to 2 repair guys in hte US and will not even sell parts. How did you solve the problem with the T5002? Mine has the same voltage difference: Good channel 2+ Volt G-S, bad channel 4+ Volt G-S
I just replaced the MOSFET for the bad channel and the amp gets hot on that channel fast and draws significant current, but the potentiometer does not change anything. Fosgate is very secretive and will not help with schematic or advise. They only refer to 2 repair guys in hte US and will not even sell parts. How did you solve the problem with the T5002? Mine has the same voltage difference: Good channel 2+ Volt G-S, bad channel 4+ Volt G-S
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