Hi,
I've just recently bought a LK202-24-USB PCB 1.3 to replace my another 202-24 that I managed to kill by accidentally shorting +5 and GND (electricity 1, me 0).
Anyhow, I'm looking at the GPO 4, 5 and 6 pins on the 1.3 and notice that it lacks the NC key that my older module had, and also that there is no revision 1.3 PDF manual. My guessing is that the NC column wasn't included in the 1.3, and I'd want to know if this would be an accurate depiction of the GPO outputs:
++++
456G
(+ = +5v; 4,5,6=GPO; G = ground)
A clarification would be appreciated. Thank you.
LK202-24 PCB Rev 1.3 GPO Pins
Hi Billious,
Thank you for posting at the forums.
It looks like you are hitting the spot. The following link gives this explanation in a little more detail.
http://www.lcdforums.com/forums/viewtopic.php?t=2898
Best Regards,
Thank you for posting at the forums.
It looks like you are hitting the spot. The following link gives this explanation in a little more detail.
http://www.lcdforums.com/forums/viewtopic.php?t=2898
Best Regards,
After the topic of *this* GPO question is sorted, I'd wonder if the Matrix Orbital people can tell me what effects on the board I killed would have bee. In essence, the 5v and Gnd of the GPOs were shorted 
(Won't do that again).
Would the effect be limited to a small number of (hopefully replaceable) components, or a general catastrophic failure of the board?
An electrical engineer friend had a look and noticed surface defects on one of the components (a transistor in the region below the USB connector, Rev 1.4) but I guess the damage is much more widespread. Also, the mounting of the PCBs makes it a little harder to survey any damage to components caused by the shorting.
Anyhow, I was prepared to throw the unit in the bin - but my friend's engineer mind is inquisitive and wonders what the effect would have been.
(Won't do that again). Would the effect be limited to a small number of (hopefully replaceable) components, or a general catastrophic failure of the board?
An electrical engineer friend had a look and noticed surface defects on one of the components (a transistor in the region below the USB connector, Rev 1.4) but I guess the damage is much more widespread. Also, the mounting of the PCBs makes it a little harder to survey any damage to components caused by the shorting.
Anyhow, I was prepared to throw the unit in the bin - but my friend's engineer mind is inquisitive and wonders what the effect would have been.
Billious,
The affects of shorting power and ground can be quite damaging. I had instances where the actual trace blows on the board. There will be a FET on the board that most likely blown too. There is a fuse right next to the unmodified floppy power connector that has also most likely blown. There is a possibility you may have damaged other components like the pic microcontroller, and the display. It's hard to tell unless some testing is done on the unit.
Are you still able to power up the display with the unmodified floppy power cable and the usb cable plugged in?
If your display doesn't work anymore, you can email me at support@matrixorbital.ca, and I can give you a couple options.
Best Regards,
The affects of shorting power and ground can be quite damaging. I had instances where the actual trace blows on the board. There will be a FET on the board that most likely blown too. There is a fuse right next to the unmodified floppy power connector that has also most likely blown. There is a possibility you may have damaged other components like the pic microcontroller, and the display. It's hard to tell unless some testing is done on the unit.
Are you still able to power up the display with the unmodified floppy power cable and the usb cable plugged in?
If your display doesn't work anymore, you can email me at support@matrixorbital.ca, and I can give you a couple options.
Best Regards,
With the USB cable connected, the display itself illuminates to what I'd estimate to be about 40-60% of its original brightness. Although Windows detects the insertion of a USB device and lists it as a COM, it doesn't display its boot screen nor does it respond to LCDC. It appears to be well and truly toast.
But never-the-less, I now have my newly purchased replacement unit and I cannot complain (but for my own stupidity).
But never-the-less, I now have my newly purchased replacement unit and I cannot complain (but for my own stupidity).