VOGONS


First post, by exs1s

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I need some assistance with a Compaq LTE Lite 4/25E that has a screen issue. This model has an Active Matrix Black and White VGA Display as shown in the pictures.

From Compaq: This model has a 9.5” (24.1 cm) diagonal COMPAQ UltraView -- a Compaq-exclusive display unique with the COMPAQ LTE Lite Family of notebook PCs. It is a brilliant active matrix black and white VGA display that offers superior performance advantages including fast response, wide viewing angle, and extremely sharp, clear images in true black and white. It can display 16 gray scales in 640 x 480 (VGA) resolution, and 64 gray scales in 320 x 200 resolution. With an optional external VGA monitor, the system also has simultaneous display capability.

When the machine first powers on, the screen is crisp and clear. Then, after about 2-3 minutes, the corners start looking like the images below. The corners gradually get dimmer and dimmer until they look so dim, there's no longer a visible image in the corners. It happens to all 4 corners.

My thoughts were, at first, the backlight, or inverter. But surely if it was the backlight the whole screen would be affected. And surely, if it was the inverter the whole screen would dim down.

Any thoughts and help would be appreciated.... Here are the images.

IMG_3183.JPG
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IMG_3183.JPG
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Entire Screen
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IMG_3184.JPG
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IMG_3184.JPG
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199.82 KiB
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Top Left
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IMG_3185.JPG
Filename
IMG_3185.JPG
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222.26 KiB
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1012 views
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Bottom Left
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Fair use/fair dealing exception

file.php?id=57163

Current Models:
LTE Lite 4/25
LTE Lite 4/33
LTE Elite 4/75
Deskpro 386s
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Reply 2 of 12, by rasz_pl

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if it was whole screen at the same time I would say bias voltage, corners only is the same thing as happened to ancient Macintosh portables, old age disease

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Reply 3 of 12, by exs1s

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DankEngihn wrote:

If you adjust the screen brightness does it change?

No, it stays the same.

file.php?id=57163

Current Models:
LTE Lite 4/25
LTE Lite 4/33
LTE Elite 4/75
Deskpro 386s
Prolinea

Please also join my Facebook Group

Reply 4 of 12, by Tiido

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That looks like damage to the panel. Does applying pressure in the corners do anything useful ?

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Reply 5 of 12, by exs1s

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Makes no difference, applying pressure. And it’s only when the screen has been on for a while.

Last edited by exs1s on 2019-01-26, 13:52. Edited 1 time in total.

file.php?id=57163

Current Models:
LTE Lite 4/25
LTE Lite 4/33
LTE Elite 4/75
Deskpro 386s
Prolinea

Please also join my Facebook Group

Reply 6 of 12, by Byrd

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It's called "vignetting", otherwise known as failure of the CCFL backlight, losing gas like a 240V used to in the day. Options are to find a better LCD, or work out someway to remove the CCFL backlighting and replace, with same or LED strip lights.

Reply 7 of 12, by exs1s

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It's not the backlight at all. I have replaced the flourescent tube with an LED strip, then even replaced the clear perspex and added a brand new diffuser sheet. Problem is still there I'm afraid.

file.php?id=57163

Current Models:
LTE Lite 4/25
LTE Lite 4/33
LTE Elite 4/75
Deskpro 386s
Prolinea

Please also join my Facebook Group

Reply 8 of 12, by SSTV2

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exs1s wrote:

It's not the backlight at all. I have replaced the flourescent tube with an LED strip, then even replaced the clear perspex and added a brand new diffuser sheet. Problem is still there I'm afraid.

Sigh, so original LCD is irreparable.

Reply 9 of 12, by Byrd

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exs1s wrote:

It's not the backlight at all. I have replaced the flourescent tube with an LED strip, then even replaced the clear perspex and added a brand new diffuser sheet. Problem is still there I'm afraid.

OK, you didn't state that.

It's moisture getting into the substrate of the LCD. Where did you get the diffuser sheet from?

Reply 10 of 12, by Windows9566

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LCD can't be fixed, and replacements are hard if not impossible.

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Reply 12 of 12, by exs1s

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libv wrote on 2022-01-26, 20:34:

Some youtuber has replaced his screen, and google tells me the Citizen H6480L-FT can be bought new-old-stock for 30usd from ebay.us

Careful, there are 3 different screens for the Lite models.

file.php?id=57163

Current Models:
LTE Lite 4/25
LTE Lite 4/33
LTE Elite 4/75
Deskpro 386s
Prolinea

Please also join my Facebook Group