Hello friends! Once again I try to repair an alpine brand amplifier and with different symptoms than the other 2 that I had to work on... this time there is audio, only the current consumption is excessive, it reaches 2.5 amps without audio and it starts to heat up 2 transistors Q306 and Q901.... remove all the output fets as well as ic 303, 304, 305, 307 and 308, to rule out that these were shorted and forced any of the Q306 and Q901 but no improvements, note that the voltages in Q306 are from B: 0v C: -21.4v and E: -21.9v those should not be the voltages according to the service manual but I cannot find which components are lowering it and forcing these transistors in advance I thank you for your help greetings
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With the black probe on the negative rail, what are the base and emitter voltages?
Is the Zener diode connected to the base shorted/leaking?
Is the Zener diode connected to the base shorted/leaking?
Does it still draw the same current as in the original post?
This regulator feeds the driver ICs. The corresponding IC in the MRP-M1000 is known for running very hot. The terminals on the transistor will actually turn colors from the heat, so... it's normal to run hot but I don't know just how hot, in that amp. It would definitely get too hot to touch, very quickly, if not clamped to the heatsink.
This regulator feeds the driver ICs. The corresponding IC in the MRP-M1000 is known for running very hot. The terminals on the transistor will actually turn colors from the heat, so... it's normal to run hot but I don't know just how hot, in that amp. It would definitely get too hot to touch, very quickly, if not clamped to the heatsink.
yes, in current it still consumes 2.5 amps and after a while it blocks with the CUR announcement.
Has any work been done on this amp before you received it?
Does any group of output transistors heat more than the others?
Does any group of output transistors heat more than the others?
thanks, it would be very helpful, tomorrow I'll try it in the car... today I injected audio and it worked for a long time, then I left it without audio and after 3 minutes it showed CUR again, I did this on my workbench I'll see what is the reaction in the car. Cheers