Thanks Bob
I fixed 2 ICOM 7000 with PD50015 burnt ; compliments for your job
and thanks for your feedback
Best 73 de IW0HEX Pasquale
(Rome, ITALY)
Il 23/07/2024 19:34, Bob ha scritto:
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Hi all, I've attached a picture of the burned and
new driver boards. There is a 1 ohm resistor on both. I hope the
picture isn't
too large for groupsIO.
Bob W4JFA
Congratulations
on
successfully replacing the driver board in your
IC-7000. Replacing those flex
cables from the PA to the MAIN is a real
challenge.
?
Now
for the reason I’m jumping in on this. The driver is
not being
damaged from excessive heat. No IC-7000’s have any
heatsink compound under the
metal substrate. Those driver transistors and the
circuit they are in seem to
be barely stable. I believe they are breaking into
an oscillation and setting
themselves on fire. Many IC-7000’s have come through
here with a smoked driver.
Almost all of them melted down while in receive.
Several smoked without ever transmitting
at all.
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The
1 ohm resistor place in the source lead is designed
to provide
a bit of negative feedback in hopes of halting
oscillation. It’s partially successful.
I’ve repaired and replaced drivers that have been
updated too.
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Thank
You
?
Paul
W. Hansen, W6XA
Amateur
Radio Service
2134
Carthage Road
Tucker,
GA 30084
(864)
222-3539
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?
Got it done. Full power out on
all bands. Old board burned.
There was no heat sink grease on it. It looks like
the heat sink design is good
but why would they apply grease on everything else
but not that?
Years ago I replaced an RF
brick in an Icom dual band
mobile, IC207. No heat sink grease on that either.
It does now. I don't get it.
Yes the radio gets quite warm.
Did very little transmitting
and still warm. A while back I worked on a
friend's 706. I was on the air
testing and talking to a friend and noticed it was
getting quite warm. My
friend that I was talking to owns about three
706's. He said that's normal.
That made me feel better cuzz I was getting
concerned.
Thanks guys. I would like to be
a 7000 owner someday
73, Bob W4JFA (near Charlotte,
NC)
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On Mon, Jul 22, 2024, 7:41 AM
RICHARD OLSON via
<richard777=[email protected]>
wrote:
The 7000 notoriously
runs
hot. I have had mine for over 10 years and
like a Timex watch it takes a
licking and keeps on ticking. I keep a small
fan blowing from the back on the
heat sink towards the front.?
Geoff, Thank you. I'll
start on the radio Monday USA eastern
time. I don't know if the new board has the
resistor or not but maybe I can add
one if it doesn't. If the added resistor is
the only change then I'm sure
there's no reason why I can't add one. I've
done things like that B4. My gut
feeling is if I can add more heat sinking,
that will help. Not sure until I see
it.?
?
The driver pcb is not
too difficult to get out and you will
see the signs if it was the cause of the
smoke. If your new driver board has
the new resistor fitted you're good to
go. But you will have to go through the
adjustment procedure contained in the
manual. I've replaced 2 and they're
still
working fine
Take pictures before
the disassembly, it really helps.
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