This is a little off topic, but it does deal with Yaesu Service.
An elderly ham I know sent in his FT-840 to Yaesu Service
after "accidentally spilling a cup of coffee on it". I say that in
quotes because I do not know it as fact, just what I
had overheard. Heresay as it were.
Facts: The rig was returned by Yeasu as "unserviceable",
along with a $60 diagnostic fee. I offered to pay the owner
for the diagnostic fee (and a bit extra) to take ownership
of the "unserviceable" rig, with the plan of "parting it out".
I was given the rig as I had done some ham favors for him.
(Drove to HRO several times to pick up items he needed,
delivered them to his home, worked on RFI in his neighbor's TV,
etc.) He was a nice codger who lived near my QTH and I was
happy to help.
I took the rig home, and the only evidence of coffee was
a small spill on the
outside of the rig. The
interior of the rig
was spic and span clean. There was no audio at all from
the speaker, but PERFECT receive audio from the line level
output from the rear of the rig. (I had hooked that up to my
computer's sound card.)
The rig would transmit a full 100w CW and FM signal,
nothing on SSB.
What was
VERY strange was that adjusting the Volume
pot changed the power output. Hmmmm.....WTH?

I related all of this to another ham, as he has far more
service experience than I. A trade was arranged, and he would
do some other rig alignment service for me. He downloaded the service
manual and found that the only thing wrong with that FT-840
was that some of the the various PC boards had been hooked up
incorrectly. (Yes, it WAS a miracle that nothing was blown!)
When the PC board jumper corrections were made, the rig
worked flawlessly, both on receive and transmit, on all bands
and all modes.Speculation:It is unclear who exactly changed the PC board jumpers
from their original configuration. I can
speculate that
it was the owner, but I never queried him about this.
He was getting on in years and at times his memory failed
him and/or he became confused. From time to time he would
buy an accessory (wattmeter, tuner, artificial ground, etc) but
hook it up or use it incorrectly. Then he would pronounce it
"broken" and take the lid off and fuss about the innards.
He had already purchased a brand new
replacement rig (The 840 was still being sold new back
then), was very happy with it, and the whole affair could only have
upset him. Perhaps I was wrong, I don't know.
Besides, I no longer owned the rig, what could I do
BUT upset him with the tale?
Why couldn't a Yaesu Certified Technician have spotted
a gross error such as misplaced PC board jumpers?
OR, did they merely look at the Service Order that read
"cup of coffee spilled on rig" and decide it wasn't even worth
opening up for a a quick "look see"?73, Ken AD6KA