VOGONS


First post, by sangokushi

User metadata
Rank Member
Rank
Member

Recently I got a Texas Instruments TravelMate 4000M laptop. When it boots, it shows a bright screen. Adjusting the brightness or contrast did not resolve the issue.
I checked the spec of this laptop, it has a passive matrix color LCD.
I was planning to install DOS games on this laptop, any suggestions how to fix the LCD screen?

Thanks!

Attachments

  • LCD.jpg
    Filename
    LCD.jpg
    File size
    149.39 KiB
    Views
    997 views
    File license
    Fair use/fair dealing exception

Reply 1 of 21, by Bondi

User metadata
Rank Oldbie
Rank
Oldbie

My guess that it's not the matrix itself but the pcb of the screen is bad. I had same issue on a different laptop. The screen was just white, i.e. all pixels were on. I fixed that by replacing the pcb inside the screen assembly.

PCMCIA Sound Cards chart
archive.org: PCMCIA software, manuals, drivers

Reply 2 of 21, by sangokushi

User metadata
Rank Member
Rank
Member
Bondi wrote on 2021-11-10, 07:34:

My guess that it's not the matrix itself but the pcb of the screen is bad. I had same issue on a different laptop. The screen was just white, i.e. all pixels were on. I fixed that by replacing the pcb inside the screen assembly.

Thanks. I will open the case and see if I can find the part no. of pcb.
I also tried to connect the VGA output to LCD TV, and TV didn't receive any signal .

Reply 3 of 21, by Bondi

User metadata
Rank Oldbie
Rank
Oldbie
sangokushi wrote on 2021-11-10, 07:59:

I also tried to connect the VGA output to LCD TV, and TV didn't receive any signal .

I don't own a Travelmate, but external VGA output is usually activated either in BIOS or by some key combinations. Did you try it?

PCMCIA Sound Cards chart
archive.org: PCMCIA software, manuals, drivers

Reply 4 of 21, by sangokushi

User metadata
Rank Member
Rank
Member
Bondi wrote on 2021-11-10, 08:08:
sangokushi wrote on 2021-11-10, 07:59:

I also tried to connect the VGA output to LCD TV, and TV didn't receive any signal .

I don't own a Travelmate, but external VGA output is usually activated either in BIOS or by some key combinations. Did you try it?

I checked their user guide. There is a DOS utility to enable the VGA out. I am not sure what's in the hard drive since I am unable to see anything on the LCD.

Reply 5 of 21, by Bondi

User metadata
Rank Oldbie
Rank
Oldbie
sangokushi wrote on 2021-11-10, 09:16:
Bondi wrote on 2021-11-10, 08:08:
sangokushi wrote on 2021-11-10, 07:59:

I also tried to connect the VGA output to LCD TV, and TV didn't receive any signal .

I don't own a Travelmate, but external VGA output is usually activated either in BIOS or by some key combinations. Did you try it?

I checked their user guide. There is a DOS utility to enable the VGA out. I am not sure what's in the hard drive since I am unable to see anything on the LCD.

All I can think of is to create a boot diskette, copy that utility on it and run it blindly or add it to autoexec.bat.

PCMCIA Sound Cards chart
archive.org: PCMCIA software, manuals, drivers

Reply 6 of 21, by sangokushi

User metadata
Rank Member
Rank
Member

@Bondi
Do you know how to open the LCD case? For new laptop, usually there are four screws covered by a small circle tape.
I tried to open it to check the pcb, but I can't find any screws holding the LCD case.

Attachments

  • DSC02843.JPG
    Filename
    DSC02843.JPG
    File size
    589.5 KiB
    Views
    906 views
    File license
    Fair use/fair dealing exception
  • DSC02841.JPG
    Filename
    DSC02841.JPG
    File size
    594 KiB
    Views
    906 views
    File license
    Fair use/fair dealing exception

Reply 7 of 21, by Bondi

User metadata
Rank Oldbie
Rank
Oldbie

I'm not sure how to open it, sorry. There may be latches around the perimeter of the case. But there is always a risk to damage the plastic opening such cases.

PCMCIA Sound Cards chart
archive.org: PCMCIA software, manuals, drivers

Reply 9 of 21, by Thermalwrong

User metadata
Rank Oldbie
Rank
Oldbie

The inverter should be fine? The backlight is working at full brightness there. If you did need to replace it, I've just found that replacing the electrolytics can get inverters working when they're not working right.

It's a bit odd that the passive LCD is showing white, that should mean full-on/active. You've tried the contrast dial, now try re-seating the LCD connector a couple of times, that can help when I see things like blank screen. You should have VGA out though...

Reply 10 of 21, by sangokushi

User metadata
Rank Member
Rank
Member

I was hoping to see some bad capacitors on the inverter, but it looks pretty clean.
I will try reseating the connectors tonight.
Also, I tried to keep turning power on and off. I saw the boot screen once from a high angle and within 10 seconds, the LCD turned to full brightness, then the boot screen disappeared.

Reply 11 of 21, by Thermalwrong

User metadata
Rank Oldbie
Rank
Oldbie

They're tough to spot, I could only see a tiny bit of discolouration on the leg of one capacitor but once I took it off, it really did stink and it was obvious it had leaked.

It's great that you have seen some display though. You could check whether the LCD panel itself has any electrolytic capacitors - those are usually surface mount and they can go bad. Epson ActionNote 500C

Reply 12 of 21, by sangokushi

User metadata
Rank Member
Rank
Member

Thanks Thermalwrong. I will check the capacitors on both LCD and inverter.
BTW, this is what the inverter board looks like.

Attachments

  • DSC02846.JPG
    Filename
    DSC02846.JPG
    File size
    804.13 KiB
    Views
    814 views
    File license
    Fair use/fair dealing exception

Reply 13 of 21, by Bondi

User metadata
Rank Oldbie
Rank
Oldbie

Hi sangokushi,
The inverter appears to be fine, as the backlight was working. Is there any other components insie the LCD assembly? There has to also be a board that handles the signals. Here is what it looked like in my case.

IMG_0927.JPG
Filename
IMG_0927.JPG
File size
9.81 KiB
Views
800 views
File license
Public domain

And it was fixed after I replaced this board that was attached to the back of the matrix.

IMG_0932.JPG
Filename
IMG_0932.JPG
File size
28.36 KiB
Views
800 views
File license
Public domain

PCMCIA Sound Cards chart
archive.org: PCMCIA software, manuals, drivers

Reply 14 of 21, by sangokushi

User metadata
Rank Member
Rank
Member

Hi Bondi,

Yes, there is a pcb inside the LCD assembly. The part no for the LCD is LM-CD53-22NTK. I found the spec online:
https://www.elecok.com/data_sheet/35474 ... AN(EN).pdf

This LCD costs ~ $130 on eBay.

Reply 15 of 21, by Bondi

User metadata
Rank Oldbie
Rank
Oldbie

That is an insane price. Given it's a passive matrix, it's really not worth the effort and money to fix it IMO. I'd rather track down a Travelamate 4000M with TFT display. It would cost less than they ask for this LCD panel. They are not common, yet not hopeless to get one.

EDIT. BTW are you sure it's a passive matrix dislpay? 4000M are TFT to my knowledge.

PCMCIA Sound Cards chart
archive.org: PCMCIA software, manuals, drivers

Reply 16 of 21, by sangokushi

User metadata
Rank Member
Rank
Member

Agree. I was hoping it's a easy fix. BTW, this is the pcb inside the LCD.

Attachments

Reply 17 of 21, by Bondi

User metadata
Rank Oldbie
Rank
Oldbie

I assume you tried to reseat those connectors? And as Thermalwrong mentioned those caps can be also bad. Is any of the caps located close to any heat source? Maybe inverter transformer?

PCMCIA Sound Cards chart
archive.org: PCMCIA software, manuals, drivers

Reply 19 of 21, by pentiumspeed

User metadata
Rank l33t
Rank
l33t

Back then, I found an early LCD monitor at work that is white like this and found a bad transistor on the LCD's board, yes on the LCD's and replaced that. Got image back, eventually transistor went again.

Just to confirm because this is repairable if you can figure out how to locate and replace the chip or transistor somwhere. But by then later LCD panel now have board directly bonded to the LCD's flex.

Cheers,

Great Northern aka Canada.