 |
For further maintenance of this board, make sure that the solder contacts on
resistors R13 and R28 are re-soldered. Also use denatured alcohol and a regular
tooth brush and saturate the board with the alcohol, and then lightly brush the
component side of the board with the brush. This cleaning will remove any
oxidation and other crap from the board.
Let the board dry for at least one half hour before using. the alcohol should
dry in a few minutes, but it may still be wet in some crevices.
Turn on the projector and let warm up for 30 minutes or so. After warm up,
follow this procedure: Press the '#' key once and then...
Press 'UTIL' on the remote, press 1, and then press 6.
Select number '3' (47.71/60) and then scroll thru all three colors by
pressing 'Color' and then 1 (red), 2 (green), 3 (blue). you should be seeing all
three color grids being displayed on the screen, now move very close to the
screen. If the projector has a reasonable setup, all three color grids should be
tight in the middle of the screen with no flare or smear to the right of the
grid.
Now, go back '#' (Util, 1, 6) and select 5 (89.30 / 70) that should put you
in the high band, scroll thru (color - 1,2,3) all three color grids should
display, now see if the grids smear to the right (in the center only).
Do the same as above, but select '6' (126.84 / 60) as the final test.
NOTE: If you notice a Tube on full brightness after you have been working
on a neckboard….. Do Not Shut Down The Projector! If you shut down the
projector right now, then chances are good that you'll spot-burn your tube!!!!
Safe shutdown procedure:
Options:
- Turn down the contrast if it makes any difference...
search for "G2" and "FULL BRIGHT". There is a procedure to shut down the
projector in this case. I think it's to remove the G2 lead but I can't
recall off the top of my head.
- Or, leave the set powered up, and wait until the HV
protection kicks in and shuts the HV off. Then power down.
- Or, pull the live neck board right off the tube. No spot
burn can happen if the tube is not connected.
- On a Marquee, if I'm going to be working on the tubes I
attach an emergency pull string to the P14 plug. If I have a G2 failure, I
pull that plug and that will shut the tubes down gracefully without harm.
- Without the G2 connected, the spot kill circuit can't
operate on a Marquee.
BTW, a super bright tube will NOT do damage... until you turn it off. Then it
spot burns 50% of the time. You probably have your G2 pin on the bottom, instead
of the top where it needs to be.
|
|
