Exchange tips and tricks for the Akai MPC4000
By JesseHolmz Thu Oct 11, 2012 11:55 pm
I got a used 4000 on ebay, it seems to be in working order, except for some lines in the LCD, and when adjusting the contrast knob, it cuts the LCD in and out. You have to get the knob at the perfect spot for it to display.

Any suggestions on going about troubleshooting this? It seems as though there'd be 2 parts to replace:

1. a new LCD screen obviously, or
2. http://www.mpcstuff.com/1a820602x.html - Contrast adjuster POT

Any suggestions?
By szr Fri Oct 12, 2012 12:06 am
Was it advertised as having lcd issues...if not get in touch with them and get them to pay for a tech to fix it... If they refuse, start a paypal dispute.

If you bought it as faulty, upload a pic so we can diagnose it easier.
By MPCdawk Fri Oct 12, 2012 12:25 am
Sounds like you are on the right track.

Lines dropping out on the LCD almost always means that the tiny electrical contacts at the edges of the LCD are failing; causing some lines not to respond to the input signals.

When the LCD goes out from turning the knob is it just the backlight that goes off or the actual display of the characters (screen remains lit up but displays nothing)?

You might have to shine a torch on the LCD screen to see if there's any characters visible if the backlight is going off.
By JesseHolmz Fri Oct 12, 2012 1:32 am
szr wrote:Was it advertised as having lcd issues...if not get in touch with them and get them to pay for a tech to fix it... If they refuse, start a paypal dispute.

If you bought it as faulty, upload a pic so we can diagnose it easier.

Yeah I bought it knowing it had issues. I got it for $385 shipped so either way I'm getting a deal. As far as I can see, everything else is in working order.

I took some short video, sorry for file size. At the end, you'll see it cutting in and out, and during that time I'm applying pressure to the knob, which will bring the screen back, until I lower pressure and it goes away. Here's the video: https://dl.dropbox.com/u/4645660/IMG_0701.MOV
By szr Fri Oct 12, 2012 11:50 am
Looks like it's just the lcd that's failing...inverter and backlight look good.. same with the pot.
Send the vid to mpcstuff to confirm this, mpc4k lcds aren't so expensive.. will still have been a good deal with that on top of the price.

When you replace it keep the old unit.. old inverter and backlight might come in handy in 10yrs time again ;)
By Clint Fri Oct 12, 2012 1:18 pm
You check all the connectors are seated nice and tights, contacts are clean?
By JesseHolmz Fri Oct 12, 2012 1:24 pm
clint246clint wrote:You check all the connectors are seated nice and tights, contacts are clean?

I haven't done anything yet, I'm just researching the possibilities first. I was planning on doing this before I spent money on anything.

Any particular tips or advice for going about it?