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R2001D issues with CPU

Posted: Thu Aug 06, 2015 9:18 pm
by n0czv
Hello!
After lowering the front panel on a non printer R2001D and reassembling after checking the RF connector, I've ended up with a problem with the LED's jumping every other one, even though the function screens are all accessible. The next LED will not light up, even though the screen is one. The generator position is also non functional.

I checked for a pinched ribbon cable or something unseated - everythin looks good.

Is there a Full Reset that I can try?

I lifted and reseated all boards, no change

The self test also only lights up every other LED's on all three vertical rows.

I still have my original low sensitivty problem.

Anyone seen this type of problem?

Thanks

Steve

Re: R2001D issues with CPU

Posted: Fri Aug 07, 2015 4:18 am
by jry
sounds like a connection problem .

Check the two DIP cables between the FP Display Kyboard and FP interface ....you may bent or have snapped off pin . If you are lucky maybe its just a seating problem.

The gen switch and LED's are on different paths so both of those cables may not be fully seated.

If the cables are good you are going to have to drop the FP assembly and troubleshoot /trace.

Would start with the GEN function first and then go to the LED's

Re: R2001D issues with CPU

Posted: Fri Aug 07, 2015 4:47 am
by jry
PS It is not a CPU issue at all.

Re: R2001D issues with CPU

Posted: Fri Aug 07, 2015 11:23 am
by n0czv
I pulled the FP apart again - nothing obvious on the ribbon connectors. I had not unplugged them when I pulled it away yesterday. I marked and removed them for now. One possibility would be that something happened internally, so I'll check continuity on the pins end to end and see if something pulled apart.

Before I lowered the FP, the unit was functional, generate/receive and all keyboard and LED functions. Low sensitivity was the issue, with the original fused BNC connector having been removed. The fuse on the wattmeter board that was added was a 7 amp fuse. Most likely something was damaged further upstream due to too much applied RF and too large of a fuse.....

Re: R2001D issues with CPU

Posted: Fri Aug 07, 2015 4:53 pm
by n0czv
Update: I lowered the FP once more and pulled the ribbon cables. No bent pins or loose connections. I ran a pin to pin continuity check between the two ends if each cable. Everything was solid.
I plugged everything back in an began refastening the FP to the chassis. When I powered the unit up with the FP loose, the self test completed normally. I was also able to go into generate mode.

With each screw that I replaced, I powered the unit up to function test.
While facing the unit, there are two side panel screws on the side into the gray side frame. One screw was longer than the other. Even easier, one was anodized black, the other silver. When I got to these, the longer screw made contact with three pins on the front panel. I did not attempt to recreate the problem. Swapping the screws took care if the clearance issue. Most likely, screws were swapped around over the years.
I am also able to receive signals over the air.
Next step is to replace the 7 amp fuse with a 1/4 amp fuse and then check receive sensitivity with another monitor. I will also mark the cover plate reference the fuse inside, even though I would like to find a fused BNC connector for the front panel....

Sometimes the simple things bite you on the butt.....

Steve, N0CZV
I still need to replace two toggle switches ( on order) and find a front cover for it......

Re: R2001D issues with CPU

Posted: Sat Aug 15, 2015 6:21 pm
by DJP126
Most likely a connection problem between the flex connectors and the motherboard.