need help w/ megatouch bad serial ports

[ponso]

I think I have a bad megatouch MB. It is not recognizing the serial ports (for the touch screen). I am out of ideas.

Anyone can point me in the right direction on repairing a serial port? I’ve spent way too much time on this board, maybe it's time to probe with the volt meter one last time.

Facts:
I’m average at electronics.
I have a Telco 486 Motherboard.
http://www.meritgames.com/Support_Ce...board%20id.pdf
Both ports seem to be bad.
The touch screens are LCD with built in controllers.
Tried 2 working touch screens (tested on another computer as working in Dos & 98) on the board on both ports. Not even the dos program drivers recognizes it.
The XL HD was tested on another computer and it seems to work.
Didn’t notice anything strange about the board like blown caps.
Ground is good on monitor and board.
When it is not plugged into the MB, the monitor controller light blinks green and solid green when touched; But when it is plugged into the board, it stays solid.
The XL boot states: No touchscreen controller found.
The game boots, but touch does not work.

[grantspain]

i worked on many older megatouch,the earth from the wall socket was extrememly important also if i remember correctly in bios there was an option to enable touchscreen
its a long time ago so i could be wrong
normally the touchscreen controller should be solid green led and when touched the led would blink
also check +12volts supply to controller-unless of course they are usb now

[Kevin Mullins]

The touch screens are LCD with built in controllers.
Tried 2 working touch screens (tested on another computer as working in Dos & 98) on the board on both ports. Not even the dos program drivers recognizes it.

What make/model touchscreen controller do you have ?

The problem you described is usually from incorrect drivers.
So it may not be that the serial port is bad, it's that the Megatouch software does not have the appropriate drivers for that particular micro-controller.

And only ONE port is actually looking/used for for the touchscreen. (COM1)
COM2 serial port was used for a networking adapter.

[ponso]

so I solved this problem by replacing the MB with another MB.  It's came off an old computer with the same slot that the megatouch board uses.  It was too much of a headache trying to figure everything out.  Everything works now.  Prob try to run dos mame or something witht the old mega MB.