I have had the audio stop working in the right channel with

OK, I bought my 2000 classic years ago and it worked fine back then as long as I had it. I traded it to a friend some time ago for about a year and just traded a week ago to get it back.
After setting up I found when sampling in from multiple sources their is no sound coming from the right channel. When monitoring the sample source on the MPC I'm not getting sound from the right channel out of the main-outs or headphones. I plugged into the digital-in to sample, and still heard no right channel. I am working with a 1/2 dead screen so I can't see the bottom vu meter bounce(which is the right channel I think)if it were, I say that to say I am worried about the input stage as much as the output stage. When monitoring the sample I switch from MONO R to MONO L to STEREO and no difference in any of the signals on my headphones or speakers. The right side is just gone. I initialized all parameters and checked everything I could think of on the O.S but I'm pretty sure that''s not the problem. I think it's some kind of circuit mabye. There is a different hiss & a humm coming from the L and R channels when you crank the input gain and volume knob. I mean it's still quiet and it sounds almost normal but the right channel has something going on with it.

If anyone knows something about this problem please tell me what you think. I can get by with working it in mono and with the 8 outs but I'd rather not. I'm still not sure if I am capturing stereo samples yet. Just nothing but the left channel, no-matter what.

had this problem recently.

i thought it was a bad potentiometer (probably the most likely suspect).

opened her up to see about replacing it, unscrewed it, wiggled it around (it's tough to get at from the top)...made some sort of inquisitive scientist faces...put it back in, screwed it all back up.

it works now.

if you don't get that lucky, you could still try replacing the pot for the main output.

chuckling at your mad scientist faces.

well, that sounds like a good place to start & easy enough.


thank you tapedeck

I'm pretty sure you have to have the volume pot replaced. mpcstuff.com charges this parts for $25! but I tried to find it elsewhere, but I couldn't find it elsewhere.
Order it from MPC stuff, and get your soldering iron ready!

somebody school me...
now, physical size might be an issue, but if it's rigged up as a voltage divider...actual pot value shouldn't matter, right?

Yesterday I opened my classic up to do what tapedeck did with his It was too hard for me to get at the underside of the pot where the circuit board and wires are. I was not able to unplug it so I just jiggled it around a little and gave a few grunts as if my hard work would pay off. It did not change a thing. However, pen I pushed on the display ribbon cable a little to try to revive a few lines in my LCD display by chance. I think I got 2 more lines back mabye... but one of the lines was where the right VU meter(bottom one)jumps on sampling screen. It was moving up so I know that my input stage is OK.

JVC is probably right. I need to buy a new volume pot and have it soldered in by someone who is skilled at soldering. I would not trust myself to do it.

I don't understand your latest post tapedeck. What do you mean?

well sorry you didn't get lucky...nice try though.

my post is a question to anyone with some electrical knowledge. the way the volume pot is wired, you can probably get by with a wide variety of replacements, so long as it fits into the physical size limits - im sure you've noticed now that it's tight in there.

im just wondering if im right or wrong about that.

Ok, I understand you now. It looks like a floppy-style power cable running into the potentiometer plug.
I don't know much about that technical side of electronic components. I just learned today that pot is short for potentiometer.

Thanks for the help tapedeck and JVC. I feel more comfortable now with the problem

Dougzaster wrote:Ok, I understand you now. It looks like a floppy-style power cable running into the potentiometer plug.
I don't know much about that technical side of electronic components. I just learned today that pot is short for potentiometer.

the pot is just a basic pot attached to a circuit board that easily plugs into the rest of the machine. so the board basically provides easy access to the pins on the pot.

you could probably save money by desoldering the pot and replacing it on the circuit board, vs buying an entire new pot+board assembly.

also, what im hinting at is that which pot you replace it with technically shouldn't really matter, it's just dealing with the physical size and extra work involved (for example you could convert it to a slide fader ... not that you would ;] ).

if you're not too confident in your electronic skills, forget i said anything

I don't think I understand...completely, the process of desoldering and soldering straight to the circuit board? I will keep it in mind though as I research buying NOS part. Interesting idea of retro-fitting a different pot from another piece of equipment.

tapedeck wrote:... the way the volume pot is wired, you can probably get by with a wide variety of replacements, so long as it fits into the physical size limits - im sure you've noticed now that it's tight in there.

The place is very tight. I actually replaced pots for both volume and gain on 2000 classic - that was over $50 for two pots! (I even did internal CF reader hack on the machine, it was most daunting soldering job I've ever done. I sold the MPC on eBay, no, I did NOT make any profit.)
Anyway, other potentiometers can be used, but it would be easier to just replace the same pots. I didn't like how MPC-2000 classic is designed, PCB board inside is not easily accessible compared to 2000XL.

Hmmmm.... I have another question I thought of before trying(or have someone else do) to replace the volume pot.

I have digital connections on my MP...I am not getting right channel out on the digital either. I was thinking volume-pot is NOT used for the transmission of the digital out signal(cause it transmits the volume of the source). Was also thinking that the digital connections are right where the volume pot is so mabye it is wired through the volume pot even though it does'nt apply with digital signal.

Does anyone know if the digital output is wired into the main volume pot? If I replace the volume pot to regain the right channel back, will it fix the digital out right channel too.

Oh, and JVC would you mind giving me a quick step by step on the pot replacement. I realize i's simple for even the novice to do but I am afraid I can't figure it out by what has been said so far.

Dougzaster wrote:.I am not getting right channel out on the digital either.

this makes me think it's not your volume pot.

I wonder what it could be then. Anyone ever heard of losing right channel audio on main out and digital out ?

Something up the line before the volume pot I guess?

thanks for everyone's interest and input so far, its been a good help.

I am wanting to bypass the D/A conversion of the MPC with the digital out plugged into my SP-808. But, with no stereo signal it's kinda useless. I can still use it the way it is now but was hoping to revive it to 100% one day. It needs a new screen too but I can handle that after reading the screen replacement post.