Ricoh MPC2500 Panel Contrast Adjustment

[captain1976]

Hi Gang,

Can anyone help me with this? I just changed the touch panel and its really dark. Of course on this model they decided to get rid of the panel contrast control so I'm cooked.

I can get into the service modes using a flashlight but need to know where I go from there to adjust it.

The old screen was bright as it should be but the touch function didn't work.

Please Help

Thanks

[totoro]

I have never had to adjust the contrast on this model. I don't even know if it's possible. You said you changed the touch panel, do you mean the entire control panel ass.? The touch screen itself is all you have to change if the touch function does not work. Usually the LCD is what goes bad if it is dark. If you did change the whole unit then just get the LCD out of the old unit or pull the touch screen out of the new unit and swap into the old unit. If you mean you changed the touch screen and then the LCD went dark then make sure that you plugged everything back in when you changed the touch screen. Otherwise your LCD went bad.

[captain1976]

Thanks for your reply,

I only changed the touch screen and I did plug everything in, but I will have to check it again tomorrow. There was a white paper or something on one side of the little plug that comes off the touch panel and plugs into the panel circuit board. It might be that this is some kind of protector and must be removed first.

[teebee1234]

Thanks for your reply,

I only changed the touch screen and I did plug everything in, but I will have to check it again tomorrow. There was a white paper or something on one side of the little plug that comes off the touch panel and plugs into the panel circuit board. It might be that this is some kind of protector and must be removed first.

Do not attempt to remove the "white paper". That is a layer of the ribbon cable and indicates that that is an updated touchscreen (originally were brown). The touchscreen will have no bearing on the backlight of the lcd. The backlight is part of the lcd and is powered by the plug with 2 white wires. Confirm that it is fully seated, but maybe you damaged something during removal (I've been known to break things once in awhile, and not always intentionally!).

[dfs]

I have changed many of the updated touch panels and yes it does look a little darker when the panel is replaced, but the LCD is visible with no issues.

Did you perform a touch panel calibration after you replaced the touch panel ?

[zed255]

Based on your description it sounds like the backlight isn't coming on. Ensure you have connected the two lead connector to the panel's HV supply.

[captain1976]

Thanks for the info, I will check it over this morning and report back.

[captain1976]

Thanks all who replied. It was my error. I had a connection unplugged and I missed it because it was hidden under a piece of plastic.

[teebee1234]

Thanks for the followup and admitting what have all done at some point (missing a connector).