I got this unit on eBay, in known non-working condition. It came from an old man who just didn't want to get it repaired. so it was a good candidate for my Winter Projects list :-)
These are some pictures of the unit. It was exceptionally clean, both outside and inside:
The fault was described as a low contrast display and no reception nor transmission. This is how the display looked:
I had read that there were problems with the A9 Power Distribution board capacitors, so I located it and replaced them.
This is the suspect board:
I got it out of the unit:
and looked at the bottom side... soldering job was not as expected on a high-end rig!
Perhaps someone had been there before?
Another thing which didn't convince me is that regulators had no thermal paste. So I put it:
Once I put the unit back on the rig, it started!!!
It couldn't be that easy right???... right!!! :-(
As soon as I put the rig into its definitive place on my shack, it failed again.
Some months passed until I had the time to work again on the rig.
OK, so I knew the problem was not on the A9 board... I checked all voltage regulators (there are quite a lot on this unit, almost on all PCBs), and everything seemed OK.
As the firmware version was old, I thought that perhaps it had something to do with the software.
(TO BE COMPLETED)