Re: Sharp LL- T17A4-B lcd Monitor
- From: jakdedert <jakdedert@xxxxxxxxxxxxx>
- Date: Sat, 14 Jun 2008 12:42:07 -0500
jakdedert wrote:
jakdedert wrote:Bought from the 'E' place for cheap. Reported symptom: video comes on and fades out. Figured it was high ESR smps caps.
Actual symptom: backlight comes on, image consist of random horizontal lines, which eventually--after some intermittent vertical scrolling--settle into a very nice image. Takes like two minutes to warm up. Shutting the monitor down for some unknown time starts the process all over again. Continuous viewing yields a stable image with good resolution, brightness and linearity. Shutting down for short periods is not problematic.
There is only one HV (100 @ 400v) cap in the ps. ESR is .46, which I assume is within tolerance. Other caps in the ps also seem fine.
This presents so like a classic cap issue (needs to warm up), that I'm going to next pull the video board and check caps there...possibly get some freeze spray and see if I can duplicate symptoms that way.
Reality check: any problem with the above procedure, or experience with this particular monitor? Any suggestions as to where to go if the above doesn't produce a dx and fix?
Thanks as always,
jak
So far, no luck. ESRd all caps on video board. All good. Bad news is that monitor rarely straightens up anymore. I got it to display correctly only once this evening, so no chance of trying to reproduce symptom via freezing components. Power supply voltages appear nominal and clean. No effect from flexing components. Reseated all cables on the video board.....
It looks like the horizonal rows are not being addressed, as the current display is a series of fine vertical lines of whatever color is predominant in that area of the display. Still some strange horizontal scrolling effects when first powered, but they only last a few seconds...two or three horizontal bars scroll down the screen, then disappear.
Any help here? Is this toast [beyond my ability to fix...]? My scope (20 mHz) is not fast enough to look at the video timing....
jak
Has this one gotten everyone as stumped as it has me?
After three days of occasional attention, the symptoms still present as before. I occasionally see the beginnings of a legible image, with bits of recognizable video scrolling down the screen. Usually these break back up into a screen full of vertical lines again; but occasionally I'll get an 'almost' image first.
Some help, even if it's just commiseration, would be appreciated. So far, not a single reply.....
jak
.
- Follow-Ups:
- Re: Sharp LL- T17A4-B lcd Monitor
- From: hr(bob) hofmann@xxxxxxx
- Re: Sharp LL- T17A4-B lcd Monitor
- From: bz
- Re: Sharp LL- T17A4-B lcd Monitor
- References:
- Sharp LL- T17A4-B lcd Monitor
- From: jakdedert
- Re: Sharp LL- T17A4-B lcd Monitor
- From: jakdedert
- Sharp LL- T17A4-B lcd Monitor
- Prev by Date: Re: TV ON switch won't latch
- Next by Date: Re: 1/4 inch socket, back nuts (black plastic)
- Previous by thread: Re: Sharp LL- T17A4-B lcd Monitor
- Next by thread: Re: Sharp LL- T17A4-B lcd Monitor
- Index(es):
Relevant Pages
|
Loading
