sher@bbn.com (Lawrence D. Sher) (05/02/91)
When a monitor fails, it could be anything. But when two monitors
partially fail in the identical way, one cannot help suspect that
this is a known failure mode, and fixing it must be known too.
So...
I have two IBM EGA "Enhanced Color Display" monitors, IBM type 5154,
that have identical failure patterns. The symptoms:
When first turned on, the picture is OK except for
unusual background brightness
occasional whole-screen glitches
ocassional raster lines near the top or center that seem misplaced
During the first few minutes of warm-up
the unusual background brightness fades to a normal black
A few minutes later a new mode of behavior suddenly appears:
the background brightness level is up again
the raster appears ragged, possibly every other line misplaced by 1-2
pixels
the beast shrieks (15 kHz?)
it smells like a component has overheated
Momentary disconnect of the signal line restores normal operation for a
few minutes.
Any ideas?
.----------------------------------------------------------------
/Internet email: sher@bbn.com
Larry Sher < US Mail: BBN, MS 6/5A, 10 Moulton St., Cambridge, MA 02138
\ Telephone: (617) 873 3426 FAX: (617) 873 3776
`----------------------------------------------------------------lrk@k5qwb.lonestar.org (Lyn R. Kennedy) (05/04/91)
sher@bbn.com (Lawrence D. Sher) writes: > When a monitor fails, it could be anything. But when two monitors > partially fail in the identical way, one cannot help suspect that > this is a known failure mode, and fixing it must be known too. > > So... > I have two IBM EGA "Enhanced Color Display" monitors, IBM type 5154, > that have identical failure patterns. The symptoms: > > When first turned on, the picture is OK except for > unusual background brightness > occasional whole-screen glitches > ocassional raster lines near the top or center that seem misplaced > > During the first few minutes of warm-up > the unusual background brightness fades to a normal black > > A few minutes later a new mode of behavior suddenly appears: > the background brightness level is up again > the raster appears ragged, possibly every other line misplaced by 1-2 > pixels > the beast shrieks (15 kHz?) > it smells like a component has overheated > > Momentary disconnect of the signal line restores normal operation for a > few minutes. > > Any ideas? > .--------------------------------------------------------------- > /Internet email: sher@bbn.com > Larry Sher < US Mail: BBN, MS 6/5A, 10 Moulton St., Cambridge, MA 0213 > \ Telephone: (617) 873 3426 FAX: (617) 873 3776 > `---------------------------------------------------------------- It's a guess but i've have a color TV like this. The high-voltage was being affected by a collection of dust attracted by the electric charge. After you get it open and discharge everything in sight with one hand and a big screwdriver ( better yet let it sit turned off overnite ), clean-up everything you can get to around the high voltage section. ------------------------------------------------------------------------- lrk@k5qwb.lonestar.org lrk@k5qwb.UUCP 73, utacfd.utarl.edu!letni!rwsys!kf5iw!k5qwb!lrk Lyn Kennedy K5QWB @ N5LDD.#NTX.TX.US.NA P.O. Box 5133, Ovilla, TX, USA 75154 -------- "We have met the enemy and they are us." Pogo -----------------