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Another IFR 1500 story

Posted: Sat Jan 28, 2017 6:45 pm
by manutea
Hi there

Got one with eBay with no video ,could buy a refurbished board with KG electronics ($ 300)and all was OK.
I didn't use it regularly and one day she partially quited with some functions still working.

-All power supply voltages are OK
-CRT is bright & clear
-Keyboard is inoperative !
-LCD display is frozen
-2 Analog meters working
-Volume/squelch are OK and also speaker ( can hear WWV on the stuck 10 Mhz and also the tones 1 & 2 on 1000 hz)
-Central commutator works on : "scope"/"analy"/"track" & "sweep" (trace on CRT) but not for "freqs", "tones","meters", "help"
-CR 2325 battery & 2 caps found dead on the CPU_memory pc board ,replaced without improvements.

Downloaded the troubleshooting manual but don't know where to commence my investigations .
If somebody could just show me a path or some points to check, that would be greatly appreciated

Thank you

Patrick FO4MM

Re: Another IFR 1500 story

Posted: Sun Jan 29, 2017 5:44 pm
by Andy Corbin
Might try pulling and re-seating the boards, cleaning the contacts with some De-Oxit while its out. The CR2325 battery only holds the memory values such as programmed frequencies, PL tones, etc. If the battery goes dead you get a "Check Sum Error" or something like that. Doesn't affect the operation other than you have to enter your data each time. Beyond that, perhaps some other folks here can help.
Andy
W4KDN

Re: Another IFR 1500 story

Posted: Mon Jan 30, 2017 5:25 am
by jry
you may have lost one of the bus driver/receivers on either the processor or I/O card if re-seating doesn't fix it.

I usually swap those tow cards to isolate and trouble shoot from there

Re: Another IFR 1500 story

Posted: Mon Jan 30, 2017 9:51 pm
by manutea
Thank you very much for your posts, guys.
i did the re-seating job already and ESR some electrolytics; found 2 that were dead on the CPU board, thats why i have suspicions for this board.

Thank you again
73s FO4MM