(Car Audio) Alpine MRD-M1000 amp no errors, but no sound

[torpex505]

Re: (Car Audio) Alpine MRD-M1000 amp no errors, but no sound

Thanks, I'll try to get some pics tonight. It is definitely on the audio end. I am able to turn the amp on and even adjust settings through the optional "remote" mounted in the dash. I had another amp at one point that did the same thing and after re-soldering the RCA inputs it started working again. That was a cheap Jensen amp though. Being that this is a higher end amp, I didn't just want to start re-soldering anything without being sure.

Also, any suggestions on how I can get a solid 12V to this thing on my workbench without running a set of jumper cables to my car battery?

Thanks for you help

[cadiman]

Re: (Car Audio) Alpine MRD-M1000 amp no errors, but no sound

I had a couple of alpine amps but I never had to work on them. Car amps have a switching power supply driven by a modulation chip. This is half of any car amp.
If you can verify the power supply is working you can move on to the audio end.

Sometimes these run around 100v or more. Look for small mosfets on both sides
If you have a scope there should be a 40khz signal feeding the mosfets to fire the inverter from the ic (14 or 16 pin). If I remember correctly the alpine amps were
built very well. As for a car that sits I would go after board issues. I had an Alfasonic
amp in my 65 Buick and I only drove it in the summer. I had the same problem you are
having. I wasn`t getting the audio signal through the preamp. I had to crank up the input signal (1v) then It would start working. I re-soldered the preamp curcuits and that fixed it. Hot and cold ( worked on warm days) not in the morning.

A picture would help alot here.

good luck!

Cadiman

[torpex505]

I just found that my Alpine MRD-M1000 amp is not putting out any sound.(I never use the car that it is in, so I have no idea when it went out) It is a Single-Channel (Sub) amp. When the amp is connected and on, I don't receive any error lights, there is just no sound coming out. I thought it may be faulty RCAs or speaker wire, but I swapped a different amp in it's place and everything works as it should. I opened the back panel, and everything looks to be ok. Any advice on what I should start checking?

Thanks