Don, Managed to do a little diagnosis.
I pulled the MAX1406 chip KPA100 U4. I see proper continuity between pin 12 of U4 and pin 25 of the MCU, and pin 11 of U4 and pin 26 of the MCU. Going back, I checked out the Vdd, Vss an Vcc voltages on U4. Vdd is 14 volts Vcc is 5 volts Vss is -5 volts It looks like, from the specification of the MAX1406 chip, it needs more like -10 volts to work correctly. I measured these on the scope before, so I only got vague responses. I guess I’ll be investigating the Vss supply. > On Nov 19, 2021, at 11:25 AM, Bill Coleman <aa...@arrl.net> wrote: > > Serial Number 2548. > > The current MCU I have is version 2.04P. (latest) > > The unit I swapped in earlier was, I think 2.03. I don’t have it with me, and > I’m not sure. > >> On Nov 18, 2021, at 5:14 PM, Don Wilhelm <d...@w3fpr.com> wrote: >> >> Bill, >> >> What is the level of the MCU (before you changed it), and what level did you >> try putting in? >> And what is the serial number of your K2? Those may help to solve the >> problem. >> >> 73, >> Don W3FPR >> >> On 11/18/2021 3:55 PM, Bill Coleman wrote: >>> U6 is kinda expensive to just replace…. >>> >>> I do have an older revision of the firmware for U6. I did try before >>> substituting the KPA100 U4, and it didn’t address the issue. >>> >>> I guess this will require more sleuthing. >>> >>>> On Nov 16, 2021, at 12:35 PM, Don Wilhelm <d...@w3fpr.com> wrote: >>>> >>>> Bill, >>>> >>>> Plug the ribbon cable in and do an end to end continuity test - KPA100 U4 >>>> pin 12 to Control Board U6 pin 25, >>>> And KPA100 U4 pin 11 to CB U6 pin 26. That will check the board wiring >>>> and the ribbon cable. >>>> >>>> If all that is OK, try replacing CB U6. >>>> >>>> 73, >>>> Don W3FPR >>>> >>>> On 11/15/2021 7:28 PM, Bill Coleman wrote: >>>>> Well, I cut out the existing U4 MAX1406 chip on the KPA100 and soldered >>>>> in a 16-pin socket. Putting in a new MAX1406 chip in the newly installed >>>>> socket and … same problem as before. The radio does not respond to >>>>> commands, pressing the PORT TEST does not result in any data output. >>>>> >>>>> I haven’t had a chance to put a scope on the pins yet to see what is >>>>> happening. >>>>> >>>>> I do find it odd that the pulse trains were reaching the CPU earlier, but >>>>> it was not acting on the commands. (eg RT1; would not turn on the RIT, >>>>> RT0; would not turn off the RIT) >>>>> >>>>> Any suggestions or ideas on how to debug this further? >>>>> >>>>> >>>>>> On Nov 5, 2021, at 3:10 PM, Bill Coleman <aa...@arrl.net> wrote: >>>>>> >>>>>> Yes, Vss Vdd and Vcc all look like appropriate values. >>>>>> >>>>>>> On Nov 4, 2021, at 3:47 PM, Don Wilhelm <d...@w3fpr.com> wrote: >>>>>>> >>>>>>> Bill, >>>>>>> >>>>>>> Make certain you have +12 volts on U4 pin 1 and +5 volts on U4 pin 16 >>>>>>> and about -25 volts (-8 to -27 volts) on U4 pin 8. >>>>>>> If those are correct, replace U4 and it should work) >>>>>>> >>>>>>> 73, >>>>>>> Don W3FPR >>>>>>> >>>>>>> On 11/4/2021 3:29 PM, Bill Coleman wrote: >>>>>>>> About 10 days ago, I was having trouble with the K2/100, as it was no >>>>>>>> longer talking to WSJT-X correctly. I could get the audio running, but >>>>>>>> it would never contact the radio. >>>>>>>> >>>>>>>> Trying to set up for CQ WW Phone, I had the same trouble with N1MM. >>>>>>>> >>>>>>>> Tried to use the PORT TEST feature by going to the SEC menu, selecting >>>>>>>> PORT, going into EDIT, and pressing the DISPLAY button. It would say >>>>>>>> TEST, but I’d see no characters transmitted. >>>>>>>> >>>>>>>> Since I use USB serial adapters, I tried two of them, to no avail. >>>>>>>> Can’t get a peep out of the K2/100. >>>>>>>> >>>>>>>> Opening up the rig and digging out the scope, if I send characters on >>>>>>>> the serial port, I see pulse trains on KPA100 U4 - the MAX1406 chip - >>>>>>>> pin 11 (R3OUT). So, it would appear that characters are reaching the >>>>>>>> main CPU. >>>>>>>> >>>>>>>> If I put the scope probe on pin 12 (T2IN), it remains locked on >>>>>>>> ground, never moving, even when I do the PORT TEST. >>>>>>>> >>>>>>>> If I remove the P1 connector from the control board, and put the scope >>>>>>>> probe on pin 1 of that connector, I DO see pulse trains from the PORT >>>>>>>> TEST. This indicates to me that the CPU is OK, but something is wrong >>>>>>>> at the MAX1406 chip in the KPA100. >>>>>>>> >>>>>>>> In addition to not getting a response from the K2, it doesn’t appear >>>>>>>> to obey commands. If I send RT1; or XT1; it doesn’t turn RIT or XIT on. >>>>>>>> >>>>>>>> I tried using a different main CPU chip (I have one with older >>>>>>>> firmware), but that doesn’t appear to make a difference. I’m wondering >>>>>>>> if my problem is a blown MAX1406 chip. >>>>>>>> >>>>>>>> Any recommendations or advice? It’s a big pain to remove the KPA100 >>>>>>>> board, so I want to make sure what I’m replacing before I go after it. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>> Bill Coleman, AA4LR, PP-ASEL Mail: aa...@arrl.net >>>>>> Web: http://boringhamradiopart.blogspot.com >>>>>> Quote: "Not within a thousand years will man ever fly!" >>>>>> -- Wilbur Wright, 1901 >>>>>> >>>>> Bill Coleman, AA4LR, PP-ASEL Mail: aa...@arrl.net >>>>> Web: http://boringhamradiopart.blogspot.com >>>>> Quote: "Not within a thousand years will man ever fly!" >>>>> -- Wilbur Wright, 1901 >>>>> >>> Bill Coleman, AA4LR, PP-ASEL Mail: aa...@arrl.net >>> Web: http://boringhamradiopart.blogspot.com >>> Quote: "Not within a thousand years will man ever fly!" >>> -- Wilbur Wright, 1901 >>> >> > > Bill Coleman, AA4LR, PP-ASEL Mail: aa...@arrl.net > Web: http://boringhamradiopart.blogspot.com > Quote: "Not within a thousand years will man ever fly!" > -- Wilbur Wright, 1901 > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to aa...@arrl.net Bill Coleman, AA4LR, PP-ASEL Mail: aa...@arrl.net Web: http://boringhamradiopart.blogspot.com Quote: "Not within a thousand years will man ever fly!" -- Wilbur Wright, 1901 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
