I have an old Alpine 3543 that plays at low level, but when turned up it shuts of and on and the chicklet turns orange. I opened her up to check for bad transistors and found none, but the toriod is singing. I used the old listening through a screwdriver trick and it is definatly the toroid. Anyone up to repairing this? It is just a little more than I am willing to jump into with my meager repair experience. This is one I would like done right. 43's are kinda hard to find...
Which are... Where? 🙂
My repair experience boils down to replacing output transistors, bias resistors and powersupply diodes. That's about it.
My repair experience boils down to replacing output transistors, bias resistors and powersupply diodes. That's about it.
Near the output transistors, are there any white rectangular resistors with 3 legs on them? They stand vertically off of the board.
Are you sure you are not running too low of an ohm load on it? Also check the ground to car, a lack of power will do that often around 10v. You can put a meter on the amp terminals and see what it goes to when you crank it up....or sometimes you can run it for a little bit and find the hot spot in your power wiring. Often the power light will dim to the music a lot if not enough power, before it shuts down. Also a short in the speaker wires to the car might, if small, cause it to protect and a bad sub can do the same thing.
Amp is not in a car and has no load or music playing to it.
When it was in car, it would play low level and shut off at anything above clock radio volume. Was running 4 ohm stereo
On test bench with no load or input, power supply makes noise. It puts an obvious load on power supply and shuts off radio hooked to same power supply.
I have not had a chance to check resistors. Maybe this weekend.
When it was in car, it would play low level and shut off at anything above clock radio volume. Was running 4 ohm stereo
On test bench with no load or input, power supply makes noise. It puts an obvious load on power supply and shuts off radio hooked to same power supply.
I have not had a chance to check resistors. Maybe this weekend.
If you can't find bad transistors or other things, guess I'd pull the rectifiers and see if the fault is in the amp or PS. Otherwise you can test the pins on the PS IC; find what is making it protect.
Sorry to hijack my own thread, but my wife bought me an old HK CA260 for Christmas and it came in today. I put it on the test bench and checked her out. DAMN! No output to the right channel! Spaeker goes to full excursion and stays. 2.33 volts dc across right +/- terminal... Any ideas. If it is a simple fix, I would really like to keep it. I have ALWAYS wanted one of these.
You have to get down to the output transistors and see if one is shorted. It is a pain to work on compared to newer amps. When I get mine fixed I also will see how great they are...or not. The PS is acting strange in mine.
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