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Reverse Voltage

Posted: Thu Nov 08, 2007 2:08 pm
by tolrtd`
Hi all,

Before shouting "buy a new one", does anyone know what exactly would break if the voltage was reversed on a LK204? My power supply got set to negative.. and my system was powered up. It was 5v reversed.

Thanks.

RE: Reverse Voltage

Posted: Fri Nov 09, 2007 10:59 am
by Clark
Hi Tolrtd`,

Thanks for your question sorry to hear that your LK204 has gravely wounded. I have seen a few improper voltage casualties returned to Matrix Orbital, and I can tell you they usually aren't pretty. For starters, it would be more than likely that your micro controller, and possibly a couple other ICs including your RAM and EEPROM chips would have been severely damaged. This would probably result in a large current draw throughout the board that would destroy a capacitor or two, and hopefully a resistor that would create a dead short to end the carnage. In this process, your display screen itself may very well have been damaged as well; if it doesn't power up, when correct voltage is applied, it is no longer with us.

Although I really hate to say it, I would quietly suggest that you may indeed have to "buy a new one".

Thanks,

Troy

Posted: Fri Nov 09, 2007 9:05 pm
by tolrtd`
Thank you for your reply Troy. The backlight turns on but it doesn't respond to my I2C input. An identical screen (both have appropriate jumpers) works fine. I reset the default screen to be blank so nothing shows up on start up anyways. Is there any way I could possibly track it down, or send it in for possible repair?

Mike

Posted: Mon Nov 12, 2007 9:13 am
by Raquel
Hello,

This other identical display module, was it also subjected to reverse voltage?

The backlight of the display is still working because it is a simple LED that would have to meet the peak reverse voltage before it blows up, but the other electronics may have already given up (and as it seems, the uC has already bid good bye - ie. no more I2C communication).

If you are interested in repairing your display, please contact support@matrixorbital.ca

Best Regards,