Gold Pic 3 Questions

[WesP]

Has anyone built a Gold Pic 3. I bought the bare board and chip and assembled it but have never been able to get it to work.I get the proper display on the LCD screen but it doesn't respond to metal. Any starting points to check would be appreciated.

Wes Pearson

I am not an electronics wizard but do have a digital meter and a PC based oscilloscope.

[Qiaozhi]

Has anyone built a Gold Pic 3. I bought the bare board and chip and assembled it but have never been able to get it to work.I get the proper display on the LCD screen but it doesn't respond to metal. Any starting points to check would be appreciated.

Wes Pearson

I am not an electronics wizard but do have a digital meter and a PC based oscilloscope.

Presumably you've checked that all the power supply voltages are correct?
i.e. the +5V and -5V. You can measure these on pins 7 and 4 respectively of IC3.
If the display is working, then it's probably quite a simple problem.
Have you examined the circuit around Q1 which drives the coil? This transistor is switched by the PIC via Q3.
It might also be good to double-check that you have all transistors inserted correctly, and all diodes with the correct polarity.

[Max]

Has anyone built a Gold Pic 3. I bought the bare board and chip and assembled it but have never been able to get it to work.I get the proper display on the LCD screen but it doesn't respond to metal. Any starting points to check would be appreciated.

Wes Pearson

I am not an electronics wizard but do have a digital meter and a PC based oscilloscope.

Hi,
could be a good idea to trace out the pulses coming from the pic and then used to sync transmitter ( the one that goes to mosfet gate)...and (if I remember well) ADC08xx or something similar sync pulses.
This way maybe you could end up with finding the error...e.g. maybe there is no good tx pulse drive or not a good timing for it.
Look for something 50-150 us pulse for tx...and trace the rest apart the lcd connections.
If you can't get any tx pulse or too strange timing there is the problem !
Sometimes PIC programming could be subtle...too...e.g. writing configuration bit on the fly missing something or making something wrong (e.g. Watchdog timer on) but would be strange that the supplier missed that point!
Maybe your problem is in pic mcu or, more probably, in adc or in amplifier or pcb connections/solderings. Have you used new parts ? Sometimes recovered parts e.g. ADC have burned pins ...
Another good issue could be soldering. Are they right soldered ??? Cause if a broken point exist...take a good look at your board with a lens.
If anything doesn't work...show here your traces of sync signals...maybe someone knows exact timing for it.

Best regards,
Max