jbm@uncle.UUCP (John B. Milton) (10/03/88)
In article <1408@cbnews.ATT.COM> ran@cbnews.ATT.COM (Robert A. Neinast) writes:
...
(monitor flicker problems)
The flickering or jumping MAY be caused by dirty pots in the monitor. Below
is a fix for that. It might also be caused by a faulty deflection transistor,
a glitchy power supply or bad line supply. If your power supply is causeing
the trouble, it might also screw up the drives and the RS-232 stuff.
*** PROCEDURE FOR CLEANING VIDEO MONITOR TRIM POTS ***
1. Shut down
2. Power down
3. Read the warning:
"WARNING: Do not attempt to remove this cover. Exposed high voltage.
No user servicable parts contained within."
4. Remove two screws from the back of the monitor
5. Take off the back plastic shell.
6. Observe that there are eight cheap little platic trim-pots. The left three
are hidden behind the speaker. They are labeled:
a. VIDEO ADJ
b. H-PHASE
c. H-HOLD
d. V-LIN
e. V-HEIGHT
f. V-HOLD
g. FOCUS
h. G2 ADJ
7. With a flat blade PLASTIC screw driver:
a. observe the current position
b. turn the pot (variable resistor) back and forth a couple times
c. set it back where it was.
d. do all eight.
* 8. Power the machine up with the diagnostics floppy in the drive.
* 9. When you get the prompt, type "s4test"
*10. Observe the new prompt "expert> ", don't get cocky
*11. Type "?" to get a full screen of help.
*12. Run the video test.
*13. Adjust those pots that you understand to your liking.
NOTE: This can be dangerous! There is about 14,000 volts running around
inside there. When you adjust those pots, use a PLASTIC adjustment tool.
You can get the right part at Radio Shack, or you might be able to borrow
one from a TV repair store. You want to be particularly careful with the *
steps above, where the monitor is open and turned on. DO NOT DO THOSE STEPS
ALONE BY YOURSELF AT THREE IN THE MORNING. Have someone else there to laugh
their ass off when you get throw across the room.
Don't send your lawer to me if something goes wrong. You do the above at
your very own personal risk.
John
--
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John Bly Milton IV, jbm@uncle.UUCP, n8emr!uncle!jbm@osu-cis.cis.ohio-state.edu
home: (614) 294-4823, work: (614) 459-7641; CP/M to MP/M, MS-DOS to OS/2