T43 bad BIOS

[Nnyan]

Hello everyone,

I have an old T43 that I setup and donated to a local school. It has been running Arch linux for over a year now with no issues. Looks like someone took it upon themselves to try to flash the bios and screwed something up. I don't know if it was the wrong bios or if power was lost/laptop rebooted in the process or what. The current state is that is "seems" to boot OK but the screen is completely dark (nothing is displayed). I've removed the cmos battery in a hope that this would help but no go. I have been unable to google and see if the bios on this thing is replaceable. I would love to be able to get this up and running again for them.

Thank you all in advance for any help.

[rkawakami]

Welcome to thinkpads.com!

A dark screen can occur for several reasons. A blown BIOS upgrade is one possible explanation. You can troubleshoot it by doing the following:

- remove the hard drive
- connect an external monitor and see if you can see the normal boot up display (the IBM splash screen, the "missing operating system" message, etc.)
- if so, then shut the system off, re-boot, but access the BIOS. Check the Config/Display menu. If the Boot Display Device is set to Analog(VGA), then you may have found your problem. With the Boot Display Device line highlighted in white, press the Enter key. That should open up a small menu where you can select ThinkPad LCD. Hit the Escape key to back up to the main BIOS menu, press F10 to save and re-boot. If the BIOS says that the LCD is the default display device, then you may have a problem with the inverter, backlight or lid switch (see below).
- if no screen activity is present on the external monitor and with the system still powered on, press the Fn+F7 key combination (hold down the Fn key, while at the same time press the F7 key). That should switch the display output between the LCD panel and the external monitor. There may actually be three conditions: LCD only, external only, both LCD and external at the same time. If pressing Fn+F7 several more times does not get any display on the external monitor, then you have a fairly serious problem.

Assuming that the BIOS has the LCD as the default device and the external monitor is working, then at least four things can make the display go dark:

- the lid switch is stuck down. It is located just to the right of the left hinge on top of the keyboard bezel. The top should be flush with the surface of the bezel so if it's below that, then "flick" it a couple of times to see if it pops up.
- if the switch appears to be good, then the problem could be due to a bad inverter or backlight. The inverter is a small, thin PC board which sits behind the bottom portion of the LCD bezel and provides the power required to run the backlight. About the only way to determine if the inverter is the problem is to replace it with a known good unit.
- the backlight could have expired. It's basically a florescent tube so it has a limited lifespan. If you (or the users) have noticed a pinkish or reddish tint to the display when the system is first turned on, then that's a good clue that the backlight is now dead. It takes some skill to replace a backlight but it can also inflict some damage to the LCD if you are not careful. Most people would replace the entire LCD panel than go through the steps to disassemble the panel, extract the backlight and solder the new one in. The light itself is fairly cheap; around $20 but you have to weigh that against ruining the entire display if your operation doesn't go right.
- and finally, there could be some other issue on the motherboard which has caused the lack of power or video display to the LCD.

edit: I just realized that there can also be another explanation for the "dead" display. Pull out the MiniPCI card from the system. On the T43, I believe that it's under the keyboard bezel, just below the touchpad.

ref: http://www-307.ibm.com/pc/support/site. ... MIGR-58837 (Hardware Maintenance Manual for T43 - types 187x)
ref: http://www-307.ibm.com/pc/support/site. ... MIGR-58791 (Hardware Maintenance Manual for T43 - types 26xx)

[Nnyan]

Thank you so much for your detailed response. I plan on going through your steps when I get home tonight and the updating this thread. Not to get too ahead of myself but what happens if IT is a bad BIOS flash? Is there anyway to replace the BIOS chip on these units? If it's somehow related to the LCD and I need to replace this is there an option where I can get a new screen with a higher resolution? The current one had 1024x768 which was too big on the 14.1 screen.

Thank you!

[rkawakami]

I believe that you can swap the LCD out for an SXGA+ (1400x1050) screen, but you also need to use the SXGA+ ribbon cable. The BIOS chip is firmly soldered down to the motherboard. You would have to have access to some surface mount desoldering equipment and a programmer. The data file containing the BIOS also needs to be in a format that the programmer can handle.

[ajkula66]

If the machine's model number (see sticker on the bottom) begins with 26xx, you'll be able to upgrade the screen to SXGA+ with a proper LCD, cable and inverter. Should the model number start with 18xx you can only run XGA.

Good luck.

Admin note: Thanks George! (forgot we were discussing a T43)

[Nnyan]

Mine is an 1875 so there goes that idea.

Anyone know of any reputable service in/around the Sacramento area that can replace the BIOS chip on this model?

[ajkula66]

BIOS chip is really not replaceable...and the cost of that type of service would likely match the cost of swapping the motherboard...

[Nnyan]

Ok so a new MB is the only option. If I was to take that (not sure it makes sense on a unit this old) route is there one model I should look out for? I would prefer something that supported a higher resolution display.

thank you all for all your help

[Nnyan]

Anyone every tried something like this:

http://www.biosman.com/biosrecovery.html

[RealBlackStuff]

Another thing to try: get PC Doctor here http://www-307.ibm.com/pc/support/site. ... MIGR-56222
It's an .ISO file, so you need ImgBurn or similar to burn this onto a CD.
Then try and run PC Doctor from that CD.

As to the BIOS recovery you mention: that's for PCs which use different types of BIOS.
Not an option for a T43 I'm afraid.