Fuse blowing is due to excessive current drain and the the first clue is the blown fuse itself. If the fuse blows with a flash a bang and splatters copper across the inside of the glass you have a hard blow caused by a dead short on the power supply, check for power switch flashing over internaly. Short circuit main filter capacitors. Shorted turns in power transformer primary winding. If fuse just separates check for short on output transistors C to E. Try isolating fault by disconnecting LT pos/neg supplies to output stage. Also check for partial shorts on speakers and speaker wires using an analog ohm meter on low ohms setting.
Now that you have isolated the fault to the output ic you need to isolate the cause of it's failure. Did it fall or was it pushed ? Since you have replaced the ic and this resulted n further failure, it was pushed. The TDA7294 operates from a +40v & -40v supply rails, are these voltages present and correct ? This ic has short circuit protection and thermal shutdown. You say the ic was fried, I assume you mean it got very hot, very quickly and self destructed.
The most likely cause may be that the ic has gone into parasitic oscillation. Check the supply rail decoupling capacitors from pins
7, 13, 8 & 15 for o/c or low capacity. Inparticular any 0.1uf decouplng caps & high value (1000uf ) caps. Check the feedback resistor in the closed loop circuit from pin 14 to pin 2 is not o/c. Measure the resistance from pin 14 to chassis for short circuit. Sorry, but I do not have a schematic for this model so I'm unable to be more specific. Good luck from Vintie.
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turns out it was a fried tda7294 amp. my new problem is that it keeps frying the 7294's.
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