my screen is dead

ok .... i just fired the 3K on, the screen flashes up an a millisecond later the light was off.

is still can see the OS is running ..... bud the screen is dark.

licks like the back light foil or do I need a new display ?

Did you try clicking the contrast button to turn the backlight back on?

First, definitely try pushing in the contrast switch as suggested above.

If that doesn't help, and you find that the display only lights up for a short time after powering up the MPC, this does sound like a problem with the inverter. The inverter is the circuit that sends power to the backlight. You can test it yourself if you are confident opening up your MPC, or you can send the MPC (or just the part containing the inverter) for repair.

To test the inverter you will need a multimeter or voltmeter. Anything that is capable of measuring up to 200 Volts AC and DC. Any cheap $10 digital multimeter will be perfect for this. Let me know if you want to test it, i'll tell you what to do.

Whatever happens, you won't need a new display. Worst case, you need a new inverter, or backlight.

ok thanks guys !!

OK, here is how to check the inverter circuit on your MPC3000. You need a screwdriver, and a multimeter, a cheap digital multimeter will do.

Turn the MPC3000 power switch off. Disconnect your MPC3000 from the mains power supply also.

On the rear, remove the 4 screws shown. Do not remove any other screws.


Remove the data knob, push the hinged display so that it is fully down, and turn your MPC3000 upside down, on a soft surface. Remove the 6 screws shown below. Do not remove any other screws.


Turn your MPC3000 right side up. Now you can swing open the top half of your MPC. Locate the circuit board called the FILTER PCB, as shown below. This is the lower of the two circuit boards nearest the mains power inlet:


Looking closely at the FILTER PCB, this shows the area we are interested in. Look for the connector labelled 'P855' and unplug that cable/connector. Here is how it looks with the cable / connector removed from P855:


So, looking at the two 'pins' of P855 - a.k.a. the 'backlight power header'. You will need to test the voltage between these two pins.

......instructions to follow in part 2.......

.....part 2.....

When the circuit is operating properly, the voltage across these two pins is 150 volts AC. Remember - this is AC, not DC. So the first step is to set your multimeter to measure AC voltage in the 200 Volt range. How to do this varies between multimeters, but remember, each meter can measure AC and DC voltage. You need to set it to measure AC.

Now, connect the MPC3000 to the mains and flick the power switch on. Safety advice here - Do not touch components with your bare hands. Be advised that some parts of the Filter PCB carry mains voltages that are high enough to cause serious injury. So don't poke your fingers in there

More safety advice: You will soon need to touch the probes of your meter to the pins of P855. Be careful not to touch BOTH pins with the same probe at the same time, and also be careful not to touch the metal part of the probe while it is touching the pin - because the probe will be live, and you will get zapped

Your meter will have two probes connected, one red and one black. Touch the black probe to one leg of P855, touch the red probe to the other leg. And now take a note of the reading on your multimeter's display. You should see a reading close to 150, which means 150 Volts AC.

If you see a very low or zero reading, it could be because the backlight power is switched off. To switch it on, PUSH the contrast knob, very firmly, one time, until you feel the 'click' of the switch. Now take the measurement again.

If you see a reading of 150VAC, or somewhere close to that (a few volts higher or lower is fine) then this tells you that your inverter circuit is working properly. So, a replacement backlight will brighten up your display

If you get a very low reading, or a zero reading, you have a problem with your inverter. This will need to be fixed before your backlight illuminates.

From his response I figured that he'd fixed it by pushing in the contrast switch.

THANK YOU ALL it works nicely !!!

First of all, thanks so much Misterwhite for the great hints on checking the inverter.
I came upon this thread through a search because my display light is going on and off randomly. The backlight foil I have is the non-solderable one from ebay and is still quite new, so I then suspected the inverter.
I checked the voltage with the meter and is giving me a stable reading of 142V, so I guess that means that the inverter is good! The display contrast switch is also working fine... I also checked the conectors
What else could it be? Any other components (capacitors...) on the filter pcb that should be replaced?
Again, sometimes the screen flashes rapidly and sometimes the light goes to sleep and it comes back on after a while. It's driving me crazy!
Any help would be much appreciated

Carlos