91 200qw instrument cluster

[Ed Kellock <EKELLOCK@ecs-inc.com>]

I recently attacked the bouncing speedo needle problem armed with a
copy of the TSB and some extra "btdt" instructions courtesy of Sarge
Schutt (and others).  My needle is now still, I can use the cruise, and the
trip computer makes sense again (no more low fuel warnings at 1/2 tank).

Unfortunately, I did not get out of there without a snag.  One of the bulbs
used to illuminate the AutoCheck display will not illuminate.  It worked fine
before.

There are two bulbs used to illuminate the panel.  One with a red rubber
and one with a yellow rubber [8-}].  The yellow illumination is used for
lesser warnings and the radio/tape display.  The red bulb is for more
important warnings and the radio/tape display when the lights are on
(dimmed mode).  

I still get the serious warnings and the radio/tape display is visible when
the lights are on.  So I know the red bulb works and I know the display
panel itself is not on the fritz.  I can see the lesser warnings if I point a
flashlight at it at an angle.  I swapped the yellow bulb with the white bulb
in the high beam indicator slot and verified that the bulb is still good.

Everything else seems to work fine.  Except the fasten seat belt warning
light.  But I'm not sure it worked before.  Or at least not since I removed
the warning chime relay several weeks ago.  The yellow bulb worked
right up until I fixed the speedo problem.  I will replace the warning chime
relay to see if that triggers the seat belt warning light.

Originally I thought I had damaged the PCB track right next to one of the
solder points.  I have examined it much more closely and found two
things: 1) the trace is not damaged & 2) it does not seem to run to
anything even remotely connected to the yellow bulb.

Unfortunately there is no diagram of the board in Bentley, so I have to
trace it by sight.  Does anybody out there have any ideas or btdt, or
better yet, a diagram of the acutal board tracks?  Can I lay this thing on a
copy machine and enlarge it without frying the board?  My swiss army
knife magnifying glass is about 1/4 inch in diameter and it's scratched.

TIA

Ed Kellock ................ Greenville, SC
91 200qw ................ 87 Coupe GT