ICOM R71A Power Issues

[Dominic1967]

I have an ICOM R71A that seemed to "die" on me. On AC, turning the receiver on only resulted in a very faint glow from the meter lamp and nothing else- no display, no receive. Nothing. Suspecting the internal power supply section, I powered it via DC cable to an Astron power supply and it came to life. I thought it was fine.

On closer inspection, I realize now it's not fine. No power through AC and on DC, I get random frequencies on the display and in memory and no reception at all. Just background hiss. The meter doesn't move. The frequencies are all wildly out of range for the receiver, like 44MHz, 55MHz, 99MHz, etc.

It's as if I now have a separate issue of bad memory board but the battery reads 3.281 volts. (Seller claimed in the description the battery had just been replaced.) I ordered a replacement power supply from a working R71A (from a reputable eBay seller I trust) and am hoping that's all it needs. Can a bad power supply cause these issues, even when powering via DC cable?

 

[Blackswan73]

Most likely the memory backup battery died causing the radio to literally lose its mind. You can buy a pre-programmed non-volatile memory module for around $75. If the seller replaced the battery and didn’t have backup power to the module, then the factory operating system is gone. Same result as a dead battery

B.S.

 

[Dominic1967]

Most likely the memory backup battery died causing the radio to literally lose its mind. You can buy a pre-programmed non-volatile memory module for around $75. If the seller replaced the battery and didn’t have backup power to the module, then the factory operating system is gone. Same result as a dead battery

B.S.

The radio worked fine for three weeks and the battery measures 3.281 volts, so that seems odd to me. Anything is possible, of course. Just weird that out of the blue, on AC I get nothing but at least the receiver powers up on DC, so my brain is stuck on thinking it's PS-related. The seller later offered to swap the module out with a known good one in an email this evening, so I'll take him up on that if the replacement PS doesn't fix it.

 

[Blackswan73]

Ok, it’s been awhile since I’ve played with my R71, in fact I’ve been considering selling it since I have 3 other radios I consider superior to the R71, including my new(to me) Drake R8. Since you’ve tried both AC and DC, with no luck that pretty much eliminates the AC supply. The R71s like my R-70, and Drake are getting long in the tooth. Common problems are E-caps that have leaked or broken down. Look for any E-caps with brown residue around the bottom. It seems there was caps made in the 90’s that are prone to failure. But my guess is still the memory module.

B.S.

 

[IK2GNP]

Most likely the memory backup battery died causing the radio to literally lose its mind. You can buy a pre-programmed non-volatile memory module for around $75. If the seller replaced the battery and didn’t have backup power to the module, then the factory operating system is gone. Same result as a dead battery

B.S.

I saw many situations like that. Similar little "non-volatile memory" boards was built also here in Italy some years ago, and much much old Icom receivers and transceivers was brought back to life thanks to that modifiation.
I agree to try this if the power supply replacement fails.