R.I.P. Icom R75?

GB46

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I'm still thinking a bad cap though but somewhere in the radio between the power jack and the processor and related power switching circuits.
Yes, that was actually my first thought, but the radio's circuitry is very complex, and I don't have the technical know-how, the proper test equipment, or the patience to track the culprit down. Even if I knew exactly which capacitor it was, I'm not adept at soldering or de-soldering tiny, tightly mounted components on PC boards. I've now stored the radio away again; it's gone into retirement after 21 years of faithful service to its owner. :)
 

GB46

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... Even if I knew exactly which capacitor it was, I'm not adept at soldering or de-soldering tiny, tightly mounted components on PC boards. I've now stored the radio away again; it's gone into retirement after 21 years of faithful service to its owner. :)
My apologies for updating a rather old thread, but my R75 is back in action, and has been working flawlessly for about a week now, with no more of that weird cycling between on and off. I'm really enjoying it! The Sangean ATS-909x is still in use and working fine as well, although I only use it with the whip (the long wire is on the R75), so signals are a bit weaker, while still quite readable.
 

GB46

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Glad to see that! Albeit with the mystery bug hanging but hey-we'll take it.
And I still have no idea what caused the problem in the first place! I have several other devices around here that went on the fritz in the past, but then seem to have repaired themselves for good without any help from me.
 

VK3RX

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I had this exact same problem i.e. one day it wouldn't power up. I'd see a faint and very brief flash on the display, and that was it.

Tried all the above too i.e. checked the internal fuse, tried a different PSU, replaced backup battery, checked the ribbon cables, no change.

Sent it off to an RF tech who specialises in amateur, CB & SWL gear, and the report was "replaced a faulty crystal on the logic PCB".

Been fine ever since.

FWIW to avoid supply power-on transient spikes, I used to first power up the PSU, then turn on an in-line switch in the DC cable then turn on the receiver. That should have been fine and is probably unrelated to the fault , but ever since I've left DC feeding the receiver 24/7.
 

GB46

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I had this exact same problem i.e. one day it wouldn't power up. I'd see a faint and very brief flash on the display, and that was it.

Tried all the above too i.e. checked the internal fuse, tried a different PSU, replaced backup battery, checked the ribbon cables, no change.

Sent it off to an RF tech who specialises in amateur, CB & SWL gear, and the report was "replaced a faulty crystal on the logic PCB".

Been fine ever since.

FWIW to avoid supply power-on transient spikes, I used to first power up the PSU, then turn on an in-line switch in the DC cable then turn on the receiver. That should have been fine and is probably unrelated to the fault , but ever since I've left DC feeding the receiver 24/7.
Interesting! I suspected that it had something to do with logic circuits. The symptom you've described is what happened here at first. Eventually I got no flash on the display at all; the radio was dead as a doornail. I put it aside for a while and used my portable instead, but after a month or so the R75 powered up just fine and was fully operational. After a few more months, however, it started that strange rapid off/on recycling I described earlier. This was at random times, often in the middle of monitoring something I really wanted to hear. Back in the storeroom it went, this time for a longer period, until I tried it again about a week ago. It's been behaving itself since then with not even a hint of a problem.

There are no qualified technicians available where I live. I would have had to send it off to Icom Canada and pay the heavy shipping charges both ways, as well as a minimum $50 for analysis on the bench, since the radio is so many years beyond the warranty period. That's why I've never had it serviced.

As for the power supply, I can see your point. My R75 has always been connected to a live power supply, even when the radio is off. Unless, of course, I've put it away somewhere -- out of sight, out of mind. :)
 

ridgescan

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Gee I have two much-missed radios sitting here in limbo that quit running-my Telefunken Opus-7 and the R71a that I wish the RF angels would sprinkle some pixi dust on bringing them mysteriously back to life like that:( but alas, these beasts have hard troubles that need my direct action if I want to see them live again. Oh well.
 

GB46

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A bargain - see what Icom Australia charge "NON-WARRANTY REPAIRS FOR PRODUCTS 10 YEARS OR OLDER ":

Icom Australia | Everything in Radio: Service and Repair Information

Thankfully we still have a few good RF techs around.
Ouch! :eek: That's truly exorbitant! It's certainly cheaper here, but imagine if you paid all the shipping and service fees, only to find out that the radio worked fine once placed on the test bench.

By the way, I have the PDF of the R75 service manual. The diagrams are nearly impossible for me too follow, as all that scrolling back and forth gives me a headache. However, I did find two logic board crystals, one of which must have been the part replaced in your radio:
X111 6050009460 S.XTAL CM200S SMD (32.768KHZ)
X112 6050009870 S.XTAL CR-567 (9.8304 MHz)

X111 uses the same frequency as commonly used in clocks and watches with quartz movements, so I imagine X111 is for the receiver's clock.
 

MisterLongwire

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Hmmm...I might have 1 I just might be selling soon.....what's the going rate nowadays, $500.00 ? Unit is immaculate, power supply, paperwork, and box. But I am out here on the west coast
 

VK3RX

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Ebay tends to indicate current market value.

There are a couple on offer there right now.
 

mbott

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The IC-R75 is about the only receiver I've sold and there is sellers remorse with that. However to make room for an IC-R71A there was no choice. I could not justify putting another receiver in the closet and I know this one has found a good home where if will be used.

--
Mike
 

n5rv

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The IC-R75 is about the only receiver I've sold and there is sellers remorse with that. However to make room for an IC-R71A there was no choice. I could not justify putting another receiver in the closet and I know this one has found a good home where if will be used.

--
Mike
Had been considering to sell mine the past week, but having second, third, fourth thoughts..... Been going through all my stuff for the swap meet in March and that puts me in the mood to put anything and everything on the pile to go. But doing it early allows me to rethink. Will put it back on the bench and keep it for a while longer...
 

GB46

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When I bought my R75 back in 1998 it was my "dream radio" -- and to think that I nearly gave up on it! It's been back in service and used heavily for about 3 weeks now, with no malfunctions whatsoever, just like out of the box. Now if there were only some decent propagation ...
 
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