No display on M527 control panel

[Byhtomit]

I have a customer who has the above titled printer, which powers on, but the display is blank and has no backlight or any indication that it is powered up.  I have replaced the formatter board, the control panel assembly, and the two cables which going between the two items.  None of which have solved the problem of the control panel being blank.

I searched the internet and found that replacing the formatter should fix the problem, but it didn't.  Since I understand that the formatter is supposed to control the display, I don't understand why this problem isn't fixed.  The only other mention of a possible fix was a brief mention of the possibility of the DC controller being faulty, but no one mentioned that it did or would solve the problem.  Would anybody be able to confirm that replacing the DC controller will fix this problem?  If not, is there any other component at fault that could be causing this problem?

Thank you,

Timothy

[Alex-TATS]

Hi Timothy,

When you power on the printer, do you hear any sounds from the printer (ie fans and/or motors spining)?

What colour is the light of the formatter (no colour, orange/red/ green)?

If the printer sounds like it is working, then do an engine test. You will have to press and hold a small button that is accessible from the rear side of the printer (via a little hole). What are the results of the test?

If the printer does not make sounds or it does not print the engine test at all, then you might have a faulty LVPS (low voltage power supply). Replacing the power supply unit would be the next logical step.

I hope this may help you,

Cheers!

[Byhtomit]

Hello Alex,

Yes, when the printer powers on, the gears engage and mechanics hum away as if there is nothing wrong.  The formatter light happens to be red, but since there is nothing on the display, I don't know if that's normal for what is wrong.

I ran the print engine test and it worked properly with 14 horizontal lines spaced about an inch apart on the paper, so it appears the print function of the printer is working.  Unfortunately, the display still doesn't. 😞

Any other ideas or suggestions?

Thank you,

Timothy

[Alex-TATS]

The engine test tell us that the printer's engine works fine.

Unplug all cables from the formatter and the DC controller and then reseat them back in.

Take a special look at the FFC (flexible flat cable) between the formatter and the DC controller at both ends of it for any signs of damage. Replace the FFC is necessary.

I hope this will help,

Cheers!