Problem is fairly straightforward, and is around the final mixdown / master
area, so that's the bit that I need a schematic for. Buried down between the
master sliders, are two s.m. dual opamps. Outputs are equal at the two
halves of one of them, but one side is low at the other. Around these two
opamps, the area is littered with gnat's-bollock-sized s.m. resistors, and
I'm pretty sure that one of these is o/c or high (it's not the opamp
itself - I changed it just in case) but because of the awkwardness of the
location and the size of the R's, it's a might difficult to see what's
connected to where, or to 'buzz' them to the IC pins. It's one of those jobs
that 'feels' as if it would resolve in a few minutes, with the benefit of a
schematic of the area :-)
Ta all !
Arfa
How are the back retainers to the nearby sliders ? Could someone have lent
on the top and pushed in the sliders and produced a crack in that area.
finger prodding results?
"N_Cook" <div...@tcp.co.uk> wrote in message
news:i1pgm8$ejm$1...@news.eternal-september.org...
No pcb / print damage that I can see. Operation of mixer in general, quite
stable. Adjacent master faders look original and free of any stress or
damage. Voltages between halves of dual opamp pretty similar. Gain of the
'low' side can be brought up to match the other side, with a wet finger
around the pins ...
Arfa
I have a nice old optics part (the rack and pinnion section got worn out) of
a Watson Barnet x50 stereo surface viewing microscope for this sort of work,
reading SM labelling. The lenses are about 30mm from the object so clears
the slider housings and some high power white LEDs for slant or normal
illumination to get in under.
"N_Cook" <div...@tcp.co.uk> wrote in message
news:i1rkb8$lvv$1...@news.eternal-september.org...
I have a high power stereo microscope, complete with its base and mechanics,
and area illumination, which I use for similar things to yourself. I also
have a high intensity white LED set in the end of an old biro pen tube. Very
handy for close-in high intensity illumination, or getting some light into
awkward places. I might dig it out and have a look, but I'm pretty sure that
this is a genuine electronic fault, rather than a pcb damage thing. Either
way, it would be a lot easier to track down with the benefit of a schematic
for the area.
Arfa