Hello I got an alpine 3544 amplifier and it doesn´t work.
The problem is, that the amplifier doesn´t turn on.
There is no voltage at the µPC494C and the transistors in the amplifier area hasn´t got there voltage.
The only voltage that i can measure is at the transistor in the power supply area. with 12,80V.
I have got an 13,9V with 10A power supply to connect it to the 3544 alpine amplifier.
And I conact the remote cable, but nothing happen.
Does somebody has got an idea. If you want photos I can upload someone.
Anybody a service manual for this amplifier?
Regards Jörg
The problem is, that the amplifier doesn´t turn on.
There is no voltage at the µPC494C and the transistors in the amplifier area hasn´t got there voltage.
The only voltage that i can measure is at the transistor in the power supply area. with 12,80V.
I have got an 13,9V with 10A power supply to connect it to the 3544 alpine amplifier.
And I conact the remote cable, but nothing happen.
Does somebody has got an idea. If you want photos I can upload someone.
Anybody a service manual for this amplifier?
Regards Jörg
Q813 is the switching transistor that delivers power to the 494. That would be the first place to check for voltage.
Email me and I'll send you the schematic.
babin_perry@yahoo.com
Email me and I'll send you the schematic.
babin_perry@yahoo.com
Perry you are great!!!!!! 
The q813 was defect but it was not to 100% defect. The way B und C was defect. B and E works.
I must order a new transistor and than i hope it will work.
Regards Jörg
The q813 was defect but it was not to 100% defect. The way B und C was defect. B and E works.
I must order a new transistor and than i hope it will work.
Regards Jörg
Hi, Perry do you still have a schematic around for this amplifier. Mine basically starts up, indicator light goes from orange to green and then a second later blows both onboard 30A fuses. I have it opened up, but I don't see anything obvious...
Anything I should check for or any tips would be great.
Anything I should check for or any tips would be great.
It sounds like it has shorted output transistors.
Email me if you want the schematic diagram.
babin_perry@yahoo.com
Email me if you want the schematic diagram.
babin_perry@yahoo.com
Thanks for the schematic, so looking at it... the output transistors would be under "Power Stage," labeled: "Q505-Q516" (2SC3421, 2SC3182, 2SA1358, 2SA1265 devices).
Awesome, will checking them while in the circuit via a DMM (diode check) be sufficient?
Yes look for shorts, if you don't find any check the outputs...the other large transistors on the sink. Note the rectifiers may normally show a short.
Well, I pulled all the output transistors and 1 output transistor tested bad (shorted), good thing I removed them because in circuit they all tested bad 😱
The other transistors on the heat-sinks tested fine, but the diode rectifiers show a short in two positions. For one, they both are shorted on the outside pins A-C (my understanding that's normal due to being connected to the transformer). Second, on D802 & D801 there's a short A-B.
If the diode/s blew wouldn't it cause more damage?
The other transistors on the heat-sinks tested fine, but the diode rectifiers show a short in two positions. For one, they both are shorted on the outside pins A-C (my understanding that's normal due to being connected to the transformer). Second, on D802 & D801 there's a short A-B.
If the diode/s blew wouldn't it cause more damage?
D801 and D802 shouldn't show a short across legs 1 and 2. They should show a short (in the board) from 1-3. Out of the board, no legs should be shorted together.
If the diodes are not shorted, reinstall all of the transistors except the defective one, clamp all semiconductors down and power it up through a 10 amp fuse. Does the fuse blow?
If the fuse doesn't blow, does it produce audio (at a low volume level)?
If the diodes are not shorted, reinstall all of the transistors except the defective one, clamp all semiconductors down and power it up through a 10 amp fuse. Does the fuse blow?
If the fuse doesn't blow, does it produce audio (at a low volume level)?
Okay, the diodes tested fine when removed (no shorts)... however the board still has shorts. Been are the readings at the pads of the diodes:
Pads 1-3: 0.4 ohms
Pads 2-3: 0.0 ohms
Pads 1-4: 0.4 ohms
Pads 4-6: 0.4 ohms
Pads 5-6: 0.0 ohms
(Pads X-Y is a pair)
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2-3 and 5-6 shouldn't be shorted. Clean the flux off of the board to see if you have a solder bridge between pads.
If I'm not mistaken, the rest are connected through traces or transformer windings so they will read as a short.
If I'm not mistaken, the rest are connected through traces or transformer windings so they will read as a short.
Yea, it's messy, but their not connected with a solder bridge. Those were the same pins that were shorted when the diodes were still in place along with another pair of pins (that connect through the transformer).
You could have a shorted rail capacitor. Another possible cause could be a transistor that's shorted to the heatsink. Confirm that no tabs of any audio transistors read anything near 0 ohms to the heatsink.
I'm assuming that you don't have the amp connected to anything.
I'm assuming that you don't have the amp connected to anything.
Nope the PCB is pulled from the amp, and here's the schematic with the pins highlighted, attached. When I measured the diodes, ALL of the audio power transistors were removed, the only ones remaining on the board are: Q507, Q503, Q505, Q508, Q504, Q506, and Q801-810.
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I would suggest that you remove the rail caps to eliminate them from the possible causes. The rarely short but there's not much left that could cause a short between those terminals.
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