PLEASE HELP badly distorted sound problem

hey everyone.
i just purchased my second mpc4000 of of ebay.
im very familiar with this model considering this is my second unit.
they guy said everything functioned properly (even made a video for me) and that it looked perfect cosmetically.
i get it in and everything looks great.
THEN....
i plug it up and it wont output any sound at all even thru the headphone jack. and even when i load sounds.
so i open up the unit and everything looked ok.
but just to be sure i disconnected and reconnected all reachable wires and cables.
turned it back on and got some highly distorted sounds. sometimes ok out of the left channel. and sometimes it would sound completely fine on both.
so i keep wiggling wires trying to get it right and nothing.
it sounds highly distorted out of one or both channels at all times. even when i play a cd in the drive. it cuts in and out, and sometimes makes a very high pitched screetchiby sound.
any ideas? can anyone help me out? any help would be greatly appreciated. i can take pictures or anything i need to do to help get this resolved.
please help me out fellas.
thanks!
-clockwork-

send it back.

return it

lol seriously guys can anyone help me out?

You could try re-seating the RAM.

Pop it out and then put it back in. The DIMMs need a surprising amount of downward pressure on them to go in properly, so be careful. Try to support the edge of the PCB with fingertips of one hand while pushing down on the DIMM.

You could also firstly try running the MPC without the RAM DIMMs at all, then it will use the 16mb that is hardwired into the motherboard somewhere. It's enough to do a test of sampling and playback with a few samples.

Just try not to stuff anything up (at least that can be seen), then the seller would have grounds for refusing the return.

Good luck!

thanks mpcdawk
im gonna try right now and ill let u know how it goes!

ok, i popped the ram out.
made a short drum sequence.
thought it was doing somewhat better but its still cutting in and out and static coming in.
sometimes i get 20 seconds where it sounds perfect like my other unit!
then i went to the internal cd sampler page and it said one channel was full and the other looked like it was going up and down in level correctly but i couldnt hear a thing!
whats the deal!?!?!!??
someone anyone please help me out
thanks again

now after lettting it play like that for maybe twenty minutes the soubd of the drum pattern is gone and all u hear now is a hiss and a high pitched whine.
someone please help. it has to be a loose cable. which one. or what is the problem?!?!!?

should i try the ram in slot #2?

You using headphones or listening to the main outs?

Can I confirm that you removed all the RAM and just used the onboard 16mb?
You recorded a new sample from CD or the analog/digital inputs?

Next things to try is leaving the RAM out and re-initializing the MPC, then maybe re-installing the OS, and pulling the memory back up battery for 60 seconds (replace with a new one to be sure) then re-initializing, and maybe also doing a re-install of the OS.

I hate to say it but this sounds... bad.

ive used both headphones and tried the main outs. same result on both.
and yes, this unit only has one ram installed and i took it out.
recording a sample would be useless because when listening to samples it does the same thing. or even worse sometimes it won't even play from the cd.
where is the memory back up battery?????
and which version of the OS should i install? and how do i go about that?
i've never had to do anything like that on my other 4000, let alone even open it up.
i greatly appreciate any help you can give me.
please let me know
thanks again

bad motherboard

return it ASAP

are you positive its a bad motherboard?
and how much does that cost to repair?
im positive before this was put in the mail to ship to me that it worked....
lemme know fellas

is this the ad/da pcb output board?
someone please help me out!
i would like to get this fixed asap
thanks again

clockwork wrote:is this the ad/da pcb output board?
someone please help me out!
i would like to get this fixed asap
thanks again

same problem here

it could be the output board but you have to make sure. I'm in the process of swapping ad/da out from a good MPC4000. Its not always the motherboard because i notice everything else works fine just distortion on output. when i sample nothing. new/used AD/DA board about 2 bills.