PCR RS-232 failure

[N9BNN]

I have a PCR-100 that worked fine for years but now cannot be found by the PCR-100 software. I have tried it on another PC with an RS232 port that works fine with my FT-857D. Could it be the RS232 chip in the PCR-100? It is a PD4723 and is no longer available. Any thoughts on this?
Mike N9BNN

 

[KE5MC]

Having worked with RS232 comm ports in the past a number of "Dominos" have to be lined up. Operating system have reassigned comm port numbers for reasons not clear. I find than's not so much the case now. Is it possible to manually 'help' the software to find the device. Yes, the chip could be bad and static discharge can take out chips via there connector contacts. Personally I have had more problems with software setup, dip switch settings and using cables not wired correctly. Bad chip would be at the very bottom of my list. Not really much help, but good luck!
Mike

 

[RFI-EMI-GUY]

That chip probably has an on board DC-DC convertor(s) to drive the transmit line voltage. (+/- 25Volts) . You might find a weak cap and it is not outputting.

 

[RFI-EMI-GUY]

If it is the chip, you can always graft in a different RS232 driver.

 

[N9BNN]

Having worked with RS232 comm ports in the past a number of "Dominos" have to be lined up. Operating system have reassigned comm port numbers for reasons not clear. I find than's not so much the case now. Is it possible to manually 'help' the software to find the device. Yes, the chip could be bad and static discharge can take out chips via there connector contacts. Personally I have had more problems with software setup, dip switch settings and using cables not wired correctly. Bad chip would be at the very bottom of my list. Not really much help, but good luck!
Mike

Thanks, Mike, for the post. I set the COM 1 port to 9600,8,N,1,N in both PCs and no response. How can I "help" the software find the device?
Mike
N9BNN

 

[N9BNN]

That chip probably has an on board DC-DC convertor(s) to drive the transmit line voltage. (+/- 25Volts) . You might find a weak cap and it is not outputting.

If it is the chip, you can always graft in a different RS232 driver.

Do you have any recommendations?

 

[KE5MC]

Thanks, Mike, for the post. I set the COM 1 port to 9600,8,N,1,N in both PCs and no response. How can I "help" the software find the device?
Mike
N9BNN

Open device manager. Find serial port items. It should show you comm port number assignments that might help. It’s been awhile since I worked with real RS232 port. Typical USB devices when plugged in will pop up with their number assignment. I’m not sure if that works for 9 & 25 pin connections.

 

[bagmouse7]

The PCR-1000 is nice because it starts sending on the RS232 as soon as you turn it on.
You can use any terminal program (PUTTY for example) to open the com port to the PCR and see the output.
Power the PRC off then on, connect to it with a terminal program at 9600:N:8:1.
You should see the PCR sending:
H100
H100
H100
H100
H100

If you see that, at least you know it is alive.
Good luck!

 

[RFI-EMI-GUY]

Do you have any recommendations?

I would first try a couple different computers that have RS232. Failing that, a USB-RS232 interface and a couple computers. If you have an RS232 tester with lights, you can see if the RX and TX data lights are flashing.

If the radio is not replying with TX data, then i would suspect the capacitors used for the DC-DC converter(s, +/- 25 V). Change those caps.

Also look to see if the TTL data on the radio side of the RS232 chip is toggling (use a scope). Maybe the problem is the uProcessor???

Failing that:

Do an exhaustive search for the OEM part. A PCR-100 was pretty cheap a few years ago. If it were my PCR-1000, I would try to find an OEM chip, or a substitute chip same pin out, failing that find a chip tah is close and graft it in.

 

[N8YX]

A quick eBay search for uPD4723 shows a number of listings. If these are in Taiwan or Hong Kong you -may- be good to go with them. Worth a try if all else fails.

 

[N9BNN]

Thanks, I will check it out.
Mike

 

[N8YX]

Speaking of PCR-100s:

Does ANYONE have the EX-2206 diagnostics software for this unit? I have one which communicates to the host computer but appears dead. Have the service manual but will probably need the software to align it after repair.