JRC NRD 535D receiver.

[docwhiteuk]

Sorry to jump straight in with a question.
I have just replaced the lithium battery on my NRD 535D and for some reason the radio is not receiving anymore. I believe the loop synthesizer is unlocked there are now two red led`s lit on the boards within the radio. I have both user and service manuals but can find very little info.
I wonder if anyone here has had any experience with these radios.
Thank you
Steve

[SiriusHardware]

My first thought was that maybe the firmware was held in RAM and retained only by the battery you have replaced, but that does not seem to the the case with these as I see mention of firmware ROMs elsewhere on the 'net'.

Truthfully, if the receiver was working before you replaced the battery- which I imagine involved taking it apart to some extent, your first course is going to have to be to backtrack over what you did while replacing the battery, especially where connectors were disconnected to allow boards to be lifted. You really need to rule that out before looking for any new fault.

[majoconz]

According to the owners manual. the CR2032 lithium cell only backs up the memory. The cell is located on the CPU board - is the board reseated in its socket properly?

[docwhiteuk]

Sorry for the delay in replying powers was off since Friday last due to the storms bringing a tree down onto the overhead lines.
Thank you for the replies, as far as I can see the boards are all seated correctly.
Now the electricity is restored I will have to look further, I can see nothing obvious. It was a straightforward job to do so I am at a bit of a loss.

[SiriusHardware]

Is there a microprocessor reset / factory reset procedure for the set in the user manual, if so try that before trying anything else.

As well as the memories, the battery may also have been responsible for retaining the 'soft' parameters (the settings which are user-alterable, but retained during power-down) and if the memory which retained those settings has lost its contents while the battery was removed it may no longer contain sane values, so try a factory reset.

In the short time I spent looking I couldn't locate a factory reset procedure for the 535 but for the 545 the method appears to be, hold down the CLR button while powering on, with any luck this may also work for the 535.

[majoconz]

If there no factory reset and the memories are garbled, try loading a new station and data into memory number 1. Some scanning receivers s are like that, when you turn it on, it wants to scan but with nothing stored it doesn't know what to do so it just sits there, fat, dumb and happy!

[docwhiteuk]

Well ladies and gentlemen, I have to confess to probably being the biggest muppet around ! I sat down with the radio and repeatedly went over what I had done and then eureka. I had managed to knock two bridging links off the adjacent board, little bit of research and then replace them in the correct configuration and she's working again. This radio was my dad's and I am so pleased that its working again. Lesson learned, thank you for all the replies much appreciated.

[Andrew2]

Very glad to hear it! These are a nice receiver and IIRC it is the last 'all analogue' one before they adopted DSP. I think it was the 545 that John Wilson condemned for 'monkey chatter'.

[SiriusHardware]

Glad you got it working, and thanks for letting us know what the problem was - someday, someone with the same problem will surf onto this thread and they'll look at those links straight away because you were good enough to flag that up as a potential issue after battery replacement.

(Welcome to the forum, by the way).

[docwhiteuk]

Thank you I am quite relieved.

[docwhiteuk]

It was worrying for awhile, thanks for the welcome.

[HamishBoxer]

We have all been there.