Quote Originally Posted by mackrackit View Post
You could test the board by removing the PIC and VERY VERY carefully plug a jumper wire in across the PIC TX/RX pin sockets. That will give a loop back to the PC when something is sent.
Tried this and got no loop back to the PC terminal display. Also put an O-scope on the jumper and see no activity when typing characters on the PC keyboard. That tells me no transmissions are reaching the RX pin on the MCU on the EasyPic6...possibly MAX202 or USB-to-serial cable bad?

[QUOTE]
Jump pins 2 and 3 at the USB/serial converter and do a loop back test.
[\QUOTE]
Did this and type characters at the PC keyboard and no loop back characters on the RX side of the terminal. Also connected an O-scope to Pin-2 of the Male DB9 connector (TX from PC) and no activity when typing characters on PC keyboard. This test tells me that the UC232A cable (USB-to-serial) is probably not wired correctly for USB to serial conversion. It still doesn't eliminate the MAX202 as the problem.

.....Connect a DVM to zero and serial pin #2 of the EasyPic and see it the is any activity from the on-board inverter chip. If the DVM fluctuates then the inverter chip is probably working.
By this do you mean connect the DVM to check for voltage at the MCU's RX pin socket location on the EasyPic6 with the MCU removed? I don't undersand which serial pin #2 you are referring to. It seems to me that connecting to the RX socket location would also confirm whether the inverter chip is working as long as I know the cable is good. Would appreciate your clarification on that.