T21 Monitor LCD Problems Also Disassembly Headaches Bezel

[gigi1234]

Hello Everyone,

I have been trying to fix the faulty display on my T21. I got a new inverter but it still doesn't work. Plus it was a total headache to take it apart!

How do I diagnose the problem? I can see a ghost image on the screen. There is no beep on boot. And an external monitor works.

Also, how in the heck do you remove the keyboard bezel???

It seems to be totally stuck on something that is near the front in the middle, where the touchpad is. I broke the thin strip on the right side and never did get it off. I was able to access the hinges because I could maneuver the back of the thing off because of the break.

I would like to get a new bezel but how would that help if I can't get the old one off? Anyone have one lying around? I happen to have an extra floppy drive I could trade.

Where do you get the thermal grease for the fan? Do you really have to do this step? The grease on mine seemed fine so I just left it.

I am not sure whether to scrap it or keep trying. I really love the computer though and nothing else is wrong with it.

Thanks in advance, Gigi

[rkawakami]

How do I diagnose the problem? I can see a ghost image on the screen. There is no beep on boot. And an external monitor works.

That diagnosis sounds like either the inverter or CCFL backlight is bad. Since you have replaced the inverter that leaves the backlight as the next possible problem. Could also be cables or motherboard however.

Also, how in the heck do you remove the keyboard bezel??? It seems to be totally stuck on something that is near the front in the middle, where the touchpad is.

Assuming you have a copy of the hardware maintenance manual as referenced in your previous thread, on pages 88-89 it shows which screws need to be removed. Possible that you have forgotten the one on the top, in the area where the touchpad normally is.

[gigi1234]

hmmm

I have removed all the appropriate screws-3 on the bottom and two on the top, including the one near the touchpad. But it just won't come off.

[rkawakami]

I'm not entirely sure at the moment since it's been a couple of weeks since I removed the keyboard bezel on my T21 the one and only time, but have you removed the CMOS battery? It's the only thing in the area that you describe that may be hanging it up. When I disassembled my T21 I removed everything that the hardware manual said to remove and I don't remember having any problems lifting up the bezel.

(edit: Warning: you will lose the date and time when the CMOS battery is removed. This will cause boot error(s) which can be fixed by entering the BIOS setup and resetting the date and time.)

[gigi1234]

Yes, there was one screw I missed and hence the trouble!

There is a screw on the bottom near the backup battery that must be removed. However, I did not see this in the manual. Maybe I missed it but looking again I don't see that part.

Thanks for responding to my questions.

But I am still confused. Is there any way to tell if this is a board issue or an LCD issue?

[rkawakami]

Is there any way to tell if this is a board issue or an LCD issue?

Simple answer: yes, replace either or both.

Long answer: That, is the $64,000 question. Without any diagnostic tools like a schematic and multimeter, the only course of action is to replace/swap components one at a time and see if that fixes the problem. The first thing to check is the simple stuff. Make sure that all of the connectors going to the LCD panel are firmly seated. Sometimes it helps to remove them and then re-insert them. Look for any cracks, nicks or (worst caes) burnt spots along the cables. Once you are satisfied that the wiring looks okay, then it's on to the harder (i.e. expensive) stuff like the LCD or motherboard.

Generally, the problem that you have described about your display not having any tint problems (red or pink light) and "flashing", points to the inverter circuit. The inverter works by taking a low DC voltage (I would guess 5 to 12 volts) and pumping it up to several hundered, if not over a thousand, AC volts in order to fire the backlight lamp. Think of it as just like the starter and ballast components inside a household fluorescent lamp. If you've ever seen one about ready to go out then you've probably seen it flicker or be hard to start. Same thing applies to the backlight in the LCD panel. A sudden "no light" from the backlight usually means that the inverter is not working (assuming no physical damage such as a fall or impact has broken the lamp).

As the backlight is normally not a part of the LCD panel that can be easily replaced, you are left with replacing the whole thing. Same thing applies to the motherboard if that is the cause of your problem. Without the required schematics it's hard to say exactly which minor component on the board has gone bad. Unless it's an obvious case of a burnt, cracked or "missing" part. And even then, you would have to identify what it is and find a replacement. Such is the nature of today's electronics. It's usually easier and faster, and sometime cheaper, to just replace an entire unit than it is to worry about finding the one small thing that is wrong.

(edit: Sorry, forgot to add this: If you are convinced that the problem is not in the wiring or with the inverter, then I would replace the LCD panel before replacing the motherboard.)

[gigi1234]

I already replaced the inverter, but that didn't work.

And it did just fail suddenly, with no prior problems. So I thought I would be the inverter.

Perhaps the inverter I got is bad too?

Yep, maybe I will just go on to replacing the LCD.

Thanks again!

[skygodtj]

If you replaced the inverter and still only see a faint image, then the backlight is the culprit.

If you replaced the inverter and see -nothing-, then the next, easy thing to replace is the video cable. If after replacing both those, you still do not see anything, then the LCD itself is next to be replaced. If THAT still doesnt do it, the motherboard is bad. And that is pretty much the order IBM techs do it..

If the inverter was off eBay, tell the seller it was DOA and see if you can get a replacement. If you get a hassle from the seller, go to a different vendor..

TJ