May 10th 05, 09:45 PM
posted to uk.rec.audio
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Audiolab Repairs
Hi,
My Audiolab 8000P went faulty on one channel, I tracked the fault to the
2SC2911 pre driver and replaced it and its compliment in both channels and
all is ok.
But my question is, what's the trimmer pot for? does anyone know where I
test and what's the parameter?
Thanks in advance
Craig
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May 10th 05, 10:12 PM
posted to uk.rec.audio
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Audiolab Repairs
In article , Craig craig-
dot-garnett-at-btinternet-dot-com@?.? writes
Hi,
My Audiolab 8000P went faulty on one channel, I tracked the fault to the
2SC2911 pre driver and replaced it and its compliment in both channels and
all is ok.
But my question is, what's the trimmer pot for? does anyone know where I
test and what's the parameter?
Thanks in advance
Craig
When I was a lad and used to work there (1983), IIRC it was to set the
bias current but I'm bu**ered if I can remember what it was now.
Why did you do both channels for, were they both U/S?...
--
Tony Sayer
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May 11th 05, 02:42 PM
posted to uk.rec.audio
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Audiolab Repairs
tony sayer wrote:
In article , Craig
craig- dot-garnett-at-btinternet-dot-com@?.? writes
Hi,
My Audiolab 8000P went faulty on one channel, I tracked the fault to
the 2SC2911 pre driver and replaced it and its compliment in both
channels and all is ok.
But my question is, what's the trimmer pot for? does anyone know
where I test and what's the parameter?
Thanks in advance
Craig
When I was a lad and used to work there (1983), IIRC it was to set the
bias current but I'm bu**ered if I can remember what it was now.
Why did you do both channels for, were they both U/S?...
Not to start with but I took the transistor from the other channel to
compare them and it was duff by the time I'd got it out and I wasn't heavy
handed with it.
I decided to change the compliments too while I was at it and neither of
them survived desoldering so they were obviously all on their last legs.
Craig
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May 12th 05, 08:47 AM
posted to uk.rec.audio
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Audiolab Repairs
"Jim Lesurf" wrote in message
...
In article , Craig
craig-dot-garnett-at-btinternet-dot-com wrote:
tony sayer wrote:
Why did you do both channels for, were they both U/S?...
Not to start with but I took the transistor from the other channel to
compare them and it was duff by the time I'd got it out and I wasn't
heavy handed with it. I decided to change the compliments too while I
was at it and neither of them survived desoldering so they were
obviously all on their last legs.
Erm... in my experience transistors do not 'wear out' in a way that means
that when you desolder them they die. What failure mechanism do you have
in
mind here?
Slainte,
Jim
Usually clumsy desoldering
Regards
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May 12th 05, 03:20 PM
posted to uk.rec.audio
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Audiolab Repairs
Jim Lesurf wrote:
In article , Craig
craig-dot-garnett-at-btinternet-dot-com wrote:
tony sayer wrote:
Why did you do both channels for, were they both U/S?...
Not to start with but I took the transistor from the other channel to
compare them and it was duff by the time I'd got it out and I wasn't
heavy handed with it. I decided to change the compliments too while I
was at it and neither of them survived desoldering so they were
obviously all on their last legs.
Erm... in my experience transistors do not 'wear out' in a way that
means that when you desolder them they die. What failure mechanism do
you have in mind here?
Slainte,
Jim
The board has obvious signs of overheating around all 4 transistors, so
considering the P&P cost more than the replacements it made sense to swap
them all out.
Craig
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May 12th 05, 03:21 PM
posted to uk.rec.audio
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Audiolab Repairs
Terry wrote:
"Jim Lesurf" wrote in message
...
In article , Craig
craig-dot-garnett-at-btinternet-dot-com wrote:
tony sayer wrote:
Why did you do both channels for, were they both U/S?...
Not to start with but I took the transistor from the other channel
to compare them and it was duff by the time I'd got it out and I
wasn't heavy handed with it. I decided to change the compliments
too while I was at it and neither of them survived desoldering so
they were obviously all on their last legs.
Erm... in my experience transistors do not 'wear out' in a way that
means that when you desolder them they die. What failure mechanism
do you have in
mind here?
Slainte,
Jim
Usually clumsy desoldering
Regards
But not in my case
Craig
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May 12th 05, 03:23 PM
posted to uk.rec.audio
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Audiolab Repairs
"Craig" craig-dot-garnett-at-btinternet-dot-com wrote in message
.. .
Terry wrote:
"Jim Lesurf" wrote in message
...
In article , Craig
craig-dot-garnett-at-btinternet-dot-com wrote:
tony sayer wrote:
Why did you do both channels for, were they both U/S?...
Not to start with but I took the transistor from the other channel
to compare them and it was duff by the time I'd got it out and I
wasn't heavy handed with it. I decided to change the compliments
too while I was at it and neither of them survived desoldering so
they were obviously all on their last legs.
Erm... in my experience transistors do not 'wear out' in a way that
means that when you desolder them they die. What failure mechanism
do you have in
mind here?
Slainte,
Jim
Usually clumsy desoldering
Regards
But not in my case
Craig
:-)
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