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My IC7000 no workin at 50 mhz and uhf

pub1969@...
 

Hi Jim, my ic7000 has problems, when I change band with the up or down button and step from the bands hf to vhf it stops working and crashes. Switching from 29.999 mhz to 30 mhz the monitor goes off and everything stops, nothing works anymore. If I turn off the power supply and turn it on again it will work in the lowest band I was operating. In vhf everything works correctly. Same problem in uhf, nothing dead everything works. Is it a software problem? I looked at the wiring diagram, it could be the up pins 51 - 52 of ic1302 failures that enable via ic2151- ic2152 and ic901 MST MCK and MDT. Or one of these failure? Maybe L7 and L9 are not enabled? Can you help me ? Sorry for my english, I'm Italian ...
Stefano

Steve W3AHL
 

What are the visible symptom details when it "stops working and crashes"?  Is the display panel blank?  If you switch to a programmed memory channel in the 6M band instead of using the UP band button does it still fail?  Does it always do this or only after being used for a while (heat  related?).

In UHF does it have the same problem as when going to 50 MHz?  Your sentence says "same problem" but then also "nothing dead everything works".  I assume you meant "everything dead, nothing works" maybe?

It sounds like a Logic board problem or flex cable problem.  Has the unit been modified or serviced recently?  Have you tried doing a CPU reset (page 25 of English user manual, erases all memory channels)?

Your English is much better than my Italian!

Steve, W3AHL

pub1969@...
 


Hello Steve thank you for answering me,
I answer with the same sequence of your questions:

the details visible when it stops working are black screen and a continuous whistle and everything is blocked nothing works, to restore the functioning I have to physically remove the power to 13.8 volts .

If I switch to a memory channel programmed in the 6-meter band, it makes the same fault.

It is not a problem related to heat, the defect is manifested both on hot and cold radio.

Yes uhf the problem is the same, same defect.

I do not think it's a problem with the flexible cable, the radio has never been opened, never repaired until now.

I have already tried to reset the cpu as described on page 25 of the user manual, but unfortunately the problem remains.

These are my answers. What do you think if I replace the cpu? I am a process technologist and I work in an electronic board assembly company, I have all the technology available for electronic board interventions also bga step 0.4 mm qfn qfp, all electronic components in general. I also have the possibility of doing x-ray, so it does not scare me to replace the components in my radio. The CPU has the firmware inside? Is it possible to read it before replacing the cpu? Is the firmware protected by reading? Thanks again for your patience, I send you a bottle of Italian wine !!

Ciao, Stefano
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Inviato da Libero Mail per Android

Lunedì, 27 Agosto 2018, 04:32PM +02:00 da Steve W3AHL w3ahl@...:

What are the visible symptom details when it "stops working and crashes"?  Is the display panel blank?  If you switch to a programmed memory channel in the 6M band instead of using the UP band button does it still fail?  Does it always do this or only after being used for a while (heat  related?).

In UHF does it have the same problem as when going to 50 MHz?  Your sentence says "same problem" but then also "nothing dead everything works".  I assume you meant "everything dead, nothing works" maybe?

It sounds like a Logic board problem or flex cable problem.  Has the unit been modified or serviced recently?  Have you tried doing a CPU reset (page 25 of English user manual, erases all memory channels)?

Your English is much better than my Italian!

Steve, W3AHL

Helmut Wabnig <hwabnig@...>
 

On Tue, 28 Aug 2018 14:09:41 +0300, you wrote:

I send you a bottle of Italian wine !!
For a bottle of wine I give the following advice:

Open the unit and remove and reseat the CPU box.
This flat tin can on top, fastened with 2 screws only.

If the error remains do the obvious,
wiggle and reseat all connectors and cables.
Careful when moving the flat cables, they easily go broke.

OE8UWW

John Rupprecht K3NOQ
 

I have similar problems, i found my 6mtr-vhf-uhf antennas are too close to my radio desk and rf trips the 12 volt supply. Antennas about 10 ft away on roof of shack. Try with reduced power or dummy load and see what happens. Ciao! // John K3NOQ

Steve W3AHL
 

I don't see any obvious signals or IC that might cause the problem.  If it were my radio I would remove the Logic board from its shielded enclosure and inspect the solder joints.  I have seen two older units from early 2006 that eventually failed intermittently (in 2015 I think).  When I inspected under a stereo inspection microscope (10-20X) with a ring light, using a micro-pick to apply pressure to each lead, I found about 40 joints that were pasty and would move under light pressure.  I could plug the Logic board into the Main, turn on the radio and get it to fail by slightly flexing the PCBA.

To repair, I had to clean the old flux off the joints first, apply new flux, then reflow each problem lead with a fine-tipped iron and just a little solder.   Normal hot air reflow wouldn't work.  After the rework the intermittent Logic board problem was fixed, although there were other problems in the UHF mixer circuit.  I didn't find any problems with the BGA IC's. 

Let us know what you finally find the problem to be and how you fixed it (hopefully).

Steve, W3AHL