Re: [Elecraft] [K2] KIO2 Malfunction
Hello Don, Thanks for the insight. I checked D4 and it seemed to be ok. I went ahead and removed U1 and the voltage on the D1 anode rose from -3.3 to -11.5! U1 must be bad. The only question is what made it that way? I'm going to order a couple of 1406's from Mouser and see if that indeed fixes the problem. If the original chip suffered from a latent defect (in other words, was the proverbial time bomb waiting to go off), then I should be ok. If the failure was due to another faulty component then at least I've got a spare... Anything else I should look for before I proceed? Thanks again! Larry, KT4G -- View this message in context: http://n2.nabble.com/KIO2-Malfunction-tp4213518p4214968.html Sent from the [K2] mailing list archive at Nabble.com. __ 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
Re: [Elecraft] [K2] KIO2 Malfunction
Larry, Other than that negative voltage supply, the 5 volt regulator, and the 12 volt line, there is just not other places to look for a problem. The MAX1406 just handles two RS-232 signals in this application, TXD and RXD, so there is nothing on the board to stress the chip. 73, Don W3FPR KT4G wrote: Hello Don, Thanks for the insight. I checked D4 and it seemed to be ok. I went ahead and removed U1 and the voltage on the D1 anode rose from -3.3 to -11.5! U1 must be bad. The only question is what made it that way? I'm going to order a couple of 1406's from Mouser and see if that indeed fixes the problem. If the original chip suffered from a latent defect (in other words, was the proverbial time bomb waiting to go off), then I should be ok. If the failure was due to another faulty component then at least I've got a spare... __ 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
Re: [Elecraft] [K2] KIO2 Malfunction
Don, That's indeed good to know. I went ahead and cut the pins to the original 1406 so I wouldn't screw up the PC board. The 1406's are on order now. I'll let you know how it goes when they get here. Thanks again! Larry KT4G Larry, Other than that negative voltage supply, the 5 volt regulator, and the 12 volt line, there is just not other places to look for a problem. The MAX1406 just handles two RS-232 signals in this application, TXD and RXD, so there is nothing on the board to stress the chip. 73, Don W3FPR -- View this message in context: http://n2.nabble.com/KIO2-Malfunction-tp4213518p4215023.html Sent from the [K2] mailing list archive at Nabble.com. __ 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
