IC-R7000 problem

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tk5ep

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Hi all,

I've been given an IC-R7000 that has been stored since several years and is not working...

I opened it and the RAM battery has been removed. I replaced it and have tested the receiver.

The VFO and keypad have no action on the RX, no valid frequency can be strored. The VFO has absolutely no action and with the keypad i can enter a frequency which is correctly displayed on the display. But when i press the ENT key, it changes to some garbage on the display.

This barbage can be stored in memories and be reset. So at least some parts are working.

I looked with a scope on several CPU pins and something is happening.. When i turn the VFO, i can see datas coming thru...

Where is the software saved ? Is it in the RAM or in the CPU ? Could it be corrupted ?

Any (good) idea is welcome... I would like to bring the baby back to live...

73, Patrick TK5EP
 

majoco

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Hi and welcome.

I assume that you have downloaded the service manual - I don't remember where I got mine from but it was definitely a download so Google should find it.
IMHO the first thing to do is to go to the section 9 voltage diagram and check every voltage regulator on every board - many of the boards have their own regulators, sometimes more than one. Look for ripple on the rails too - hopefully you have a scope.
The logic unit holds the firmware in RAM so unless there has been a catastrophic failure it should be good. Unplug and replug every connector you can find - be aware though that some look like PC board connectors but they are actually soldered in - don't pull too hard on them!
If the radio has been in storage for quite a while, then some of the electrolytics will be suspect. Many people have shotgunned the capacitors - there are capacitor kits available from some guy in Canada.
Join the Yahoo group, there are many on there with more experience than I!

Good luck, it's a great radio - eventually! My display board is still in it's trial period although it hasn't gone wrong for three months now!
 

tk5ep

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Hi,

Thanks for the reply.
Yes, i have the manuals and i used it to track some voltages. Mainly on the PLL and LOGIC boards, both been concerned by my frequency problem.

But you're right, i should start with the voltage diagram...

When you say that the firmware is in RAM. What RAM do you mean ??

I already joined the Yahoo group. No answer so far...

73, Patrick
TK5EP

Hi and welcome.

I assume that you have downloaded the service manual - I don't remember where I got mine from but it was definitely a download so Google should find it.
IMHO the first thing to do is to go to the section 9 voltage diagram and check every voltage regulator on every board - many of the boards have their own regulators, sometimes more than one. Look for ripple on the rails too - hopefully you have a scope.
The logic unit holds the firmware in RAM so unless there has been a catastrophic failure it should be good. Unplug and replug every connector you can find - be aware though that some look like PC board connectors but they are actually soldered in - don't pull too hard on them!
If the radio has been in storage for quite a while, then some of the electrolytics will be suspect. Many people have shotgunned the capacitors - there are capacitor kits available from some guy in Canada.
Join the Yahoo group, there are many on there with more experience than I!

Good luck, it's a great radio - eventually! My display board is still in it's trial period although it hasn't gone wrong for three months now!
 

majoco

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IMHO IC8 on the logic board is the RAM and IC7 talks to it. Both of them are kept alive by the 3volt battery BT1.
 

tk5ep

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I looked on the processor datasheet and the RAM is only 128 bytes and ROM 4kbytes.
The firmware is certainly in ROM and the RAM is only for the firmware pointers ...

The memories and stored in the external RAM.

It would be very surprising if the ROM is corrupted...

The previous owner told me that the receiver worked before being stored...

No clue what can be wrong. Everything i checked is OK. (so far)

73, Patrick

IMHO IC8 on the logic board is the RAM and IC7 talks to it. Both of them are kept alive by the 3volt battery BT1.
 

majoco

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I probably got the memory RAM as IC7 then - especially as it is kept alive by the backup battery.
 
D

DaveNF2G

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I have read that, on the older Icom receivers (R-7000, R-71a, etc), once the onboard battery goes completely dead, the onboard memory is wiped and the chips have to be reprogrammed. As Icom no longer services those models, this is a practically impossible recovery.
 

KA1RBI

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I have read that, on the older Icom receivers (R-7000, R-71a, etc), once the onboard battery goes completely dead, the onboard memory is wiped and the chips have to be reprogrammed. As Icom no longer services those models, this is a practically impossible recovery.
Wrong again, Dave. The R71 does have this problem, but not the R7000. The R7000 backup battery is only for memory retention. And, re: the R71 you can still (afaik) purchase an after market plugin board that fixes the memory loss issue (piexx?) for that receiver.

As for the problem that the OP reported with his R7000, I bought one at a hamfest a few years ago that had symptoms very similar. I brought the unit back to life by replacing all the electrolytic capacitors ($25 or so in parts). This was a very common problem in the R7000's. No guarantee this will fix the problem Patrick is having, but that's definitely where I'd start. Unless there is an actual fried component, the radio should come back to life. The toughest ones to replace are in the VCO board, as it's a bit tricky to remove and replace!

73

Max
 

majoco

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Here's an EPay listing for all the electros...

Icom IC-R7000 Receiver Capacitor Replacement Kit | eBay

...and somewhere I have seen a YouTube of someone showing all the procedures. I understand that the DC-DC board is a prime candidate for replacing capacitors but fortunately (touch wood) the only ones I have had problems with were the ones on the display board - that little board runs quite warm.
 

tk5ep

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OK, i might consider changing all caps...
Until now, all my measures didn't put me on a track...

I finaly got some answers on the Yahoo mailing list...

73 Patrick
Accueil
 

tk5ep

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I just ordered a set of caps. I found a cheaper offer by the same guy !
Now waiting and heating the solder iron...

Patrick


OK, i might consider changing all caps...
Until now, all my measures didn't put me on a track...

I finaly got some answers on the Yahoo mailing list...

73 Patrick
Accueil
 

KA1RBI

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I just ordered a set of caps. I found a cheaper offer by the same guy !
Now waiting and heating the solder iron...

Patrick
I shall be interested to hear how you make out. **If** I recall (not 100%) but I did the boards one at a time with a powerup between each one (as a regression test) expecting the "logic" board would be the one that made the difference but it was another unit (display board?) after replacing the caps the radio started working OK just with lingering problems with tuning frequencies above 512 MHz. There are two electrolytics on the VCO board and the one on the VCO > 512 MHz was leaking (semi shorted) which was causing that fault. Also, separately don't even consider doing this without a copy of the service manual (should be able to find online)!

73

Max
 

iMONITOR

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The older ICOMs, IC-R7000, as well as the IC-R71 are known for solder joints going bad, in addition to the capacitors failing.
 

tk5ep

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Apr 6, 2017
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OK,

Yes, i will change the caps board after board starting with the LOGIC and the PLL boards.
I hope this will bring them back to live...

I will check every cap dismantled to get an idea, and check if they are leaking or getting dry.

On my spectrum analyzer, they were leaking and corroding the tracks.

I will also look for dry joints.

While waiting for the caps, i will open the R71E i've been given at the same time and which is also silent !

73, Patrick.
 
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