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

[iFixStuff]

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

I've got one in for repair that is receiving intermittent 9v to the power control ic.
Anybody have a schematic of Alpine MRP-M1000 or anybody know why I'm not getting a constant signalk to the pwm ic?

[vinceroger69]

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

that pic gives me

strange.

picture opens ok now i think its been edited.

[stj]

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

that pic gives me

Invalid Attachment specified. If you followed a valid link, please notify the administrator

strange.

[winner_dude]

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

Ive attached a pic of the circuit board let me know which component I can take a close up pic. I also marked the empty spot with a arrow not sure if theres supposed to be a transistor there if so whats the part number. Thanks

[winner_dude]

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

Which component I have one apart right now trying to fix no sound issue bought it used I can upload a pic let me know which component also if u can upload a pic of yours since mine was missing a mosfet in the power circuit dunno if its suppose to have one there or not in the first place.

[Deazy]

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

Does anyone happen to have an Alpine mrp-m1000, I was removing a broken component and scratched away the marking on it and need to know the specs of it.

[rdunnit]

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

I am new here and I ran into this post. I am an avid car audio enthusiast (have been ever since I bought my first car audio setup:a Kraco underdash 8 track unit and some surface mounted speakers).
I have repaired a lot of amps in the past but haven't repaired a class D yet.
One thing that I may suggest is look up Perry Babin on diyaudio.com. He is a guru when it comes to car audio amplifiers and has helped quite a few people on the diyaudio forum. I hate to see you trash an amplifier unless the board is burnt to a crisp as so often happens when people put amplifiers in a load not intended to be run. I have read of people placing amps down to as low as .125(.13 rounded) in competition!!! Crazy but then it's all about winning in competition.

Robert

[torpex505]

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

it might have been the RCAs, i had a similar problem, switched the RCAs resoldered the new one and POW worked like a charm

I actually had desoldered and disassembled them, pinched the internal connection prongs together(i noticed that they were not very tight) then resoldered them. I checked the continuity and everything seemed fine on that end. thanks for the suggestion though.

[daRk_Kon]

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

it might have been the RCAs, i had a similar problem, switched the RCAs resoldered the new one and POW worked like a charm

[torpex505]

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

I just wanted to give an update as the thread starter. I decided to trash the amp. I had a smaller one laying around and decided to go that route instead. Good luck to you dirtrider, hope you can figure your's out.

I did want to thank everyone who tried to help me though.


On a side note:
I find it amusing that such a pricey amp (if I remember right, I paid ~$900 for it) is being replaces by it's ancestor: Alpine MRV-T757 (which was ~$400 new).

[mbates14]

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

Go into the amplifier's menu, and make sure output is set to ON.

I ran into this mistake once.

[kaboom]

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

This is not an amplifier in the normal sense. It's a "class D' PWM switching amp. Not talking about the DC-DC converter here.

The final in that is to amplifiers what SMPS are to heavy linear supplies.
Fine for a sub amp where lots of power, less than full audio bandwidth, and relatively high efficiency are specified.

Those ICs will make it interesting... In the Memphis 16-500D and successors, their PWM ICs for the final had their part numbers sanded off.

Check the 7815/7915s for the opamp supplies.

-Paul

[cadiman]

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

Pictures always help!

[dirtrider383]

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

im new to all this hi tech stuff but my mrd is doing the same thing can u guys explain it the retard way lol it powers up fine and everything i had it working went inside came back out turend it on and nothing any help wud be nice

[cadiman]

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

Since you have the amp out of it`s shell it is easy to check the outputs and mosfets with your meter for any shorts. You can do a quick check and look for any base/collector shorts. If you find something then you will need to remove the outputs and check each one to find the bad transister. I don`t know anything about your amp, but It should go into protect mode with a light of some kind if this is the case.
after further inspection of your pictures that board is a double printed curcuit board same as the Delcos. Anywhere there are jumpers from one side of the board to the other is where you will have a bad solder joint. Also any heavy components will have to be checked where they solder to the board. My first scope came from a garage sale and had tubes in it. You don`t need much for audio even the driver ics only run around 44 khz for the power supplies in most car amps that I have worked on.

[torpex505]

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

Cool, I'll check craigslist and local pawnshops for a cheap scope to try that out. Thanks for the info. I was able to power it on with a cheap psu, but I didn't really get anywhere with it. I tried tracing with my voltmeter but couldn't find anything.

[cadiman]

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

I have bench tested all of my amps with an old vista power supply rated around 10amp.
as said above you only perform low level bench test for operation not a party.

Also do not ever run any amp on the bench without outputs mounted to heatsink. the mosfets in the power supply will burn up in a second (I was a punk kid then and made lots of mistakes).

I don`t like all the surfacemount ics on that amp ( never good in a car ) and can understand why to not jump into resoldering.
If you can signal trace the rca inputs with your ipod hooked up and the amp turned on ( to let the signal through). you should be able to figure out where the signal is missing.

All you need is an old cheap scope if you can find one.

[torpex505]

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

Here are some pics. I took close-ups of the more heavily populated areas.

[torpex505]

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

Awesome, I didn't think that there would be enough amperage. I have a cheap $10 PSU sitting in the closet that i picked up about a year ago as a backup. I'll get it hooked up tonight then.

Thanks!

[Th3_uN1Qu3]

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

You can just use a spare ATX PSU, it wouldn't be enough to drive it at full power but it should work for just starting it up.