I'm helping a friend troubleshoot a KX1. Unit was fine after build. Took unit apart and installed 30m/80m. Then 3rd digit did not work on display. He re-flowed some pins on the unit (I do not know which ones and he does not recall) and now the display is not functional at all.
I started him checking through the resistance checks on page 26 of the document. Pins 1 & 20 of U1 has about 500 ohm on it, whether U1 is installed or not. We have been all through the voltages with D3/D2, U8, and U9. All the regulators seem good. Though I did caution him about running from a wall wart. His 12v seems a bit low. Around 11.5v. As a result of this, the voltage on pin 4 of U1 is a bit low at 3.5v. Also pin 14 is at 2.5v where it is supposed to be low. I find little odds and ends here that are not right, but if the display is not functional I would expect bigger issues. Some voltage off on clock inputs wouldn't seem the culprit. Also the ATU was not plugged in. We have worked through the troubleshooting tree, problem 00, I need to review with him where he is on problem 20. We looked through problem 26. No pins are bent on U1. All of the voltages were good except the 2 mentioned. I have not built a KX1, but built a K2. My thoughts are to go through the various resistance and voltage checks for the 3 build sections and see if we can make any sense of it. Am I headed in the right direction? Am I missing anything obvious since I am not familiar with the KX1? I'm hoping my friend (John, K6OWD) got setup on the list today. Dave Wilburn NM4M K2/100 S/N 5982 K3/100 S/N 766 _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
