Matrix Orbital Corp

Hello, I was hoping someone might be able to help me out with a problem that has started happening with my MX221 display.

I've had it for several months now, and recently it has started switching into extremely high contrast state. Setting the contrast to 0 (using the display touch utility on the driver CD, for example), would make it just about readable, but still a bit too high contrast. Anything above that would be just black.

After a while (and for no reason I can determine), it will switch back into normal contrast state, in which case 0 contrast is completely white, and I have to set the contrast back to middling to be readable. After a few hours (or sometimes even a day or so), it has usually flipped back to high contrast state, and I have to set the contrast to 0 again, and so on.

I am running Windows XP Pro SP2, if that helps, and I've tried uninstalling and re-installing the drivers and LCDC from the CD, and I've also tried LCD Smartie as an alternative control program, but nothing seems to have helped.

Does anyone have any suggestions on how I can stop this behaviour?

Thanks,

Alex

Hi Alex,

Can you leave it on with just the unmodified floppy power, and tell me whether the contrast varies?

If you get the same results, please email me at tlam@matrixorbital.ca for rma options.

Um, unmodified floppy power? I'm sorry, but don't understand.

As far as I can tell, my MX221 draws power from it's USB connection, and there are no further connections to it. I am using the display externally, and it is plugged into one of the USB sockets of the PC.

There is a connection below the fan headers for external power from your pc's power supply. The floppy power connection is for power the fan headers, and you can use it to power up the display. I wanted to power it with out any communication to isolate the problem to just the device. I think it is a display fault, but I want to make sure before we rush into anything.

Ah, OK, I understand now. Unfortunately the PC it is connected to is a Hush Mini ITX based PC, and has no floppy drive, or cables for attaching one. Could the same test be performed by uninstalling the drivers and leaving it plugged into the USB port perhaps? If not, I will have to try and get hold of another PC that can be left turned on for a day or two to test it.

If this is an uncorrectable hardware fault, and my only option would be to send it back to the USA (I live in the UK), I think I would have to just live with it and keep adjusting the contrast manually. Apart from the postage costs, I got stuck for customs charges when it came through the first time.

Alex,

You shouldn't have to live with that problem. Did you buy the unit directly from us or from Kustom PCs?

BTW we are from Canada.

Directly from you, KustomPCs didn't have any in stock, and I didn't realise it would cost me customs charges to buy it from you until it arrived with a bill. Otherwise I'd have probably waited! :-)

Can you give me the PCB revision?

Um, can you tell me how to determine the PCB Revision?

Looking at the back of the display, there is an IC with a white sticker with "V2.1" on it, would that be the PCB Revision?

It should be right on the back under PK202-24-USB lettering close to the top of the board. Your usb cable might be in the way, so you may need to take it off..

Ah yes, it was hidden under the USB cable. Mine says LK202-24-USB, though, not PK, and Rev 1.6, Canada

Would you be ok with sending the unit back to Canada?

Is this a known hardware problem with that revision of PCB or something, then? It hasn't done it again for the last 3 days, so I'm leaning more towards living with occasionally resetting the contrast rather than trying to arrange a return to Canada, particularly if I'd have to pay customs duties on the replacement.

Alex,

I have seen something similar, but it happened a lot quicker than 3 days. I wanted to test it here. I seen that you have reinstalled drivers, and reinstalled LCDC which still didn't work, so it led me to believe that it is a hardware problem. Can you test the unit on another PC, so we can eliminate the problem whether the issue comes from your PC or the unit?

OK, I've got hold of an alternative PC I can use for testing. I'm on holiday over the next week, so I'll leave it hooked up to the test PC while I'm gone, and if it hasn't happend by the time I return, I'll assume it was a temporary problem.

Thanks for your help with this