MPC3000 not work LCD

Hi.

MPC3000 not work LCD...
but button and pad work on.
I've tested Top pannel[Buttons & Pads, Slide, LCD] from other mpc3000.
and ad/da no problem.

http://blog.naver.com/jycrew/150044256465

not work lcd and ad/da relay now.

why not work?

Please your advice.

Maybe you need a new lcd screen? I am pretty sure that the s3000 uses the same size lcd unit.

thanks for your reply.

But i replaced to other mpc3000's LCD from my mpc3000's LCD, PAD, Buttons.
no problem. everything works fine.

but not work in my mpc3000.
Maybe cpu board is bad.

check also all the connections....
sometimes it's a connection problem...

if not probably motherboard

Do you have a voltmeter? There is a wire going from the LCD to the power supply of the MPC. You should measure around 130 V (AC). I currently have the same problem. The LCD is fine but the power is missing. I only measure 0V but I haven't found the problem yet.

Can someone tell me whether the background light is connected to the switch labeled "Display Contrast"?

seymorskinner wrote:Do you have a voltmeter? There is a wire going from the LCD to the power supply of the MPC. You should measure around 130 V (AC). I currently have the same problem. The LCD is fine but the power is missing. I only measure 0V but I haven't found the problem yet.

Can someone tell me whether the background light is connected to the switch labeled "Display Contrast"?

backlight inverter is broke

Thank you Manilla.
Where is the backlight inverter located?
Thanks.

Manilla. I actually did replace the inverter already (didn't know it was called inverter) but the lcd still doesn't work. The guy who sold me the MPC sent me the repalcement inverter. Maybe its a faulty one? Is there a way to check it out with a ohmmeter? Or anything else on that board which could be faulty?

Thanks.

The inverter powers the backlight not the LCD. You should still be able to read the LCD without the backlight, though it will be very dark.

If you can't read the LCD, then check the voltage at the connector of the LCD, you should see -12V on one of the pins (can't remember which one). If you can't find the -12V, then the LCD is not getting power.

Thanks MPCHunter.

The LCD works indeed, its just dark. Sorry, I meant the backlight not the LCD.

seymorskinner wrote: Or anything else on that board which could be faulty?

What brand is the replacement inverter you received? What does it look like? Is it a drop-in replacement for the Nichia inverter on the Filter Board or is it an after market one?

It's really hard to put the Nichia inverter incorrectly -- it only fits on one way. So if that's the one you've put in, then check you solder joints to make sure they are good.

The other aftermarket inveters have leads hanging off of them, so you may have wired it up incorrectly. There is a thread here about installing an aftermarket inverter in a MPC 3000. I don't have the link off hand, but if you use the search you should be able to find it.

Thanks. I actually got the exact same inverter, its a Nichia. No way this one could have been wrongly installed, just works one way. But I do remember that I had problems with the soldering (I did this a couple of weeks ago), the iron didn't seem to lay down properly. Maybe this is the whole problems, the connection itself. Need to have another look at it.

I have this same problem and my friend is coming to check the voltage with a voltagemeter in a few days. From where I should measure the voltage?

Have you tried pressing down on the contrast dial until it clicks, it doubles as an on/off switch for the backlight.