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 ______________________________________________________________ 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
