From: Stuart Biggar (Stuart.Biggar_at_opt-sci.Arizona.EDU)
Date: Thu Feb 03 2000 - 14:10:27 EST
> From owner-thinkpad_at_cs.utk.edu Thu Feb 3 11:59:17 2000
> From: "Jeffrey D Grinnell" <grinnell_at_acunet.net>
> To: "ThinkPad List" <ThinkPad_at_cs.utk.edu>
> Date: Thu, 03 Feb 2000 13:59:11 -0500
> MIME-Version: 1.0
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> Subject: Video Strangeness on 770
> List-Unsubscribe: <mailto:thinkpad-request_at_cs.utk.edu?Subject=unsubscribe>
>
> I've got a factory refurbished Thinkpad 770 that I've had for over a
> year now. Aside from a bit of peeling paint from the palmrest area it
> has served me well.
>
> Recently, however, I've been experience random blanking of the display.
> The display will simply go black. I've checked my settings for the
> display under the power management and that doesn't seem to be the
> problem. The blanking of the display happens at random times anyway so
> I doubt it is related to the power management software.
>
> Once the screen blanks I can get the display to turn on again by
> hitting Fn + F7 to toggle the display between
> external/internal/external+internal. This has worked every time, but
> I've also seen the display blank again within seconds of turning it on.
>
> I've also noticed that the problem seems to occur more frequently soon
> after I restart from a suspend. Could it be that I'm seeing the
> beginning of the end for the display lamp? If so what kind of estimate
> can someone give me to have this repaired as I believe my unit is now
> out of warranty (one year on refurbed units)
>
> Just to be complete...I'm running Warp 4.0 fixpack 8 using the v1.2
> video drivers available from the Thinkpad device driver matrix. I have
> not as yet booted to my Win95 partition to determine if the problem
> occurs there as well; something I will definately do before I opt to
> send the unit off for service.
>
> Jeff
>
>
Jeff,
I had a similar thing happen on my 770E (PII 266, 224 MB, 8 GB disk).
I sent it to Easy Serv and they replaced the inverter board and the
CPU card. Seems to have cured the problem.
Note that the black screen problem I had was seen with two OSs (NT 4
SP3 as preloaded by IBM and Sun Solaris 7 x86 - a Unix variant).
It turns out that what was happening was that the backlight was
going off, probably due to a bad inverter board. With a very bright
light I could see windows and the mouse pointer and the mouse still
tracked and the window system responded - it was just VERY difficult
to see anything. If I shut down and restarted, the backlight would
work for an unpredictable time and then it would shut off again...
Every once in a while I would get a variation in the display brightness,
almost like a flicker. One time I could also hear a high pitched whine
when the flickering was happening - probably the inverter operating at
too low a frequency, especially as I have poor high frequency hearing
due to noise exposure as a helicopter pilot (and age).
I called IBM and they set up a return to Easy Serv. They promised
4-5 day turn around but it was more like 10. My 770E does now work
like it should.
Good luck,
Stuart
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