T40 LCD Problem

Message

weimao · #1 Post by **weimao** » Wed Jun 07, 2006 8:21 pm

My Thinkpad T40 has a problem with its LCD screen. When I turn on the computer, the display looks kind of red and goes back to normal a few seconds later. But after a while (1 minutes or so), I can hear a slight sound (sizzle?) from the LCD part and then the display turns off while the computer is still power-on (black screen).

Is this problem related to "inverter" (I am not sure if I understand this)? Any ideas? I reaaly appreciate your help.

NS · #2 Post by NS » Wed Jun 07, 2006 8:52 pm

EDIT: I am not very sure about this, but it is the LCD inverter which is causing this type of problems. There might be some other parts involved in this LCD blackout problem.

Welcome to this forum, weimao.

weimao · #3 Post by **weimao** » Wed Jun 07, 2006 9:39 pm

Do you think the LCD itself has problems? If the problem is with the inverter, then where can I buy an inverter for this specific laptop (T40)? What is the inverter "model"?

What other parts might be involved in the problem?

Actually, I did send this laptop to IBM EasyServ. But it was said that some parts were spilled (although I recall I've NEVER spilled the computer) and it costs about $900 to repair (to replace the LCD and an inverter). So now, I come here to see if I can fix the problem by myself with a lower budget.

Let me know if you have further advice/ideas? Thank you very much!

#4 Post by **GomJabbar** » Wed Jun 07, 2006 10:10 pm

My thought from posts I have read on this in the past is that your backlight is going out. I thought Kyocera had a good post on this in the following thread.

http://forum.thinkpads.com/viewtopic.php?t=21532

Get part number FRU's from the following link (This is for the 14.1" LCD. For the 15" LCD, click on the link in the page below.)
14.1inch LCD service parts - ThinkPad T40/p, T41/p, T42/p

You can order from IBM/Lenovo from the following link. You may have to call IBM Parts, as the web store doesn't often find the part. You can also Google an FRU part number to find other web stores that carry it.
IBM Maintenance Parts Retail

Here is a link to the Hardware Maintenance Manual that shows how to disassemble the LCD. FRU part numbers are here as well.
Hardware Maintenance Manual - ThinkPad T40/p, T41/p, T42/p

weimao · #5 Post by **weimao** » Thu Jun 08, 2006 8:28 am

Your information is very helpful!

I found an inverter here. The FRU seems correct. What do you think?
http://www.pcsurplusonline.com/viewprod.cfm?id=8057

If I need to replace the backlight also, where can I get one? I did not find it on IBM website. What is the formal name of backlight (CCFL?)? May I use a backlight designed for other laptop models? Thank you!

weimao · #6 Post by **weimao** » Thu Jun 08, 2006 8:44 am

May I use this backlight (NEW Lamp LCD backlight Dell/Compaq/IBM/HP/Sony/Gateway):
http://cgi.ebay.com/NEW-Lamp-LCD-backli ... dZViewItem

or this (BACKLIGHT for IBM Thinkpad T20 T21 T22 T23 LCD):
http://cgi.ebay.com/BACKLIGHT-for-IBM-T ... dZViewItem

Sorry for naive questions...

#7 Post by **GomJabbar** » Thu Jun 08, 2006 12:27 pm

Can't say. I have not had my display apart. But if it was me, I would order the backlight that has the FRU number for my model ThinkPad. Make sure you order the one for your screen size - either 14.1" or 15".

Humpa · #8 Post by **Humpa** » Mon Jun 19, 2006 4:14 pm

weimao, any update on this?

Did you receive your inverter?

I'm looking into an inverter from ebay - I have a 15" svga screen on my T42, so the part you found doesn't appear to be compatible. Though the one I found on ebay seems to be generic (they list a bunch of 15" part numbers, including the one I need: 93P4161)
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 6867319262

My screen also has the red tint when it first powers up (or when dispaly comes back on). It also just started blanking out every minute or so (actually, backlight just goes off) when I leave the display brightness on max. As long as I dim the display, it keeps working like normal.

But from what I can determine, there is no separate backlight - I assume if it is my backlight, then I'd need a new lcd. But with my symptoms, I'm hoping it is just the lcd inverter

Hanson · #9 Post by **Hanson** » Mon Jun 19, 2006 4:32 pm

weimao wrote:
Actually, I did send this laptop to IBM EasyServ. But it was said that some parts were spilled (although I recall I've NEVER spilled the computer) and it costs about $900 to repair (to replace the LCD and an inverter). So now, I come here to see if I can fix the problem by myself with a lower budget.

Does EasyServ have any excuse to refuse repair other than a spill? That seems to be all I am hearing.

christopher_wolf · #10 Post by **christopher_wolf** » Mon Jun 19, 2006 4:58 pm

Hanson wrote:
weimao wrote:
Actually, I did send this laptop to IBM EasyServ. But it was said that some parts were spilled (although I recall I've NEVER spilled the computer) and it costs about $900 to repair (to replace the LCD and an inverter). So now, I come here to see if I can fix the problem by myself with a lower budget.
Does EasyServ have any excuse to refuse repair other than a spill? That seems to be all I am hearing.

Anything that qualifies as "unwarranted treatment or abuse" I think; the spill excuse is most amenable to this as the evidence is barely visible, especiall in a photo unless it was a severe "spill," and doesn't require them showing any broken or bent parts, harder evidence if you will, to the customer.

Paxonator · #11 Post by **Paxonator** » Mon Jun 19, 2006 10:17 pm

Humpa wrote:weimao, any update on this?

Did you receive your inverter?

I'm looking into an inverter from ebay - I have a 15" svga screen on my T42, so the part you found doesn't appear to be compatible. Though the one I found on ebay seems to be generic (they list a bunch of 15" part numbers, including the one I need: 93P4161)
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 6867319262

My screen also has the red tint when it first powers up (or when dispaly comes back on). It also just started blanking out every minute or so (actually, backlight just goes off) when I leave the display brightness on max. As long as I dim the display, it keeps working like normal.

But from what I can determine, there is no separate backlight - I assume if it is my backlight, then I'd need a new lcd. But with my symptoms, I'm hoping it is just the lcd inverter

That sounds like the backlight to me. You can just buy the backlight itself but it can be quite the task to replace on some lcds. I seem to remember being able to buy a light from an online retailer for about $10 plus shipping so it's worth a shot.

Humpa · #12 Post by **Humpa** » Mon Jun 19, 2006 10:21 pm

Paxonator wrote: That sounds like the backlight to me. You can just buy the backlight itself but it can be quite the task to replace on some lcds. I seem to remember being able to buy a light from an online retailer for about $10 plus shipping so it's worth a shot.

I can find no info on the backlight though.
There's not even any mention of it in the Hardware Maintenance Manual:
http://www-307.ibm.com/pc/support/site. ... MIGR-46464

You don't think it is the lcd inverter?

Humpa · #13 Post by **Humpa** » Thu Jun 22, 2006 1:41 pm

I'm going to call tech support.
Hopefully they can tell me what part I need to replace.

My problem is getting worse. Now I have to keep my brightness all the way down at the minimum - and even that doesn't work 100%. It seems that once the laptop heats up to normal operating temperatures, the backlight/display will sometimes go off. Sometimes closing/opening the lid will bring it back, and sometimes it won't.

There is also another related symptom, and this started happening before anything else. Occasionally my display will become unreadable/screwed-up. I will get a half-dozen vertical lines, and the rest of the screen is sort of jumbled/distorted. Kind of like some of the pixels have jumped to the right (or left?) and some havent moved. I can see enough to close everything down and turn it off, but nothing is actually readable. This only seems to happen when I move the laptop (especially if I pick it up from the left side) - so I was originally thinking I had a bad cable or connection inside.

If anyone has any insight into my problem, I would love to hear it.

Paxonator · #14 Post by **Paxonator** » Thu Jun 22, 2006 1:46 pm

Humpa wrote:
Paxonator wrote: That sounds like the backlight to me. You can just buy the backlight itself but it can be quite the task to replace on some lcds. I seem to remember being able to buy a light from an online retailer for about $10 plus shipping so it's worth a shot.
I can find no info on the backlight though.
There's not even any mention of it in the Hardware Maintenance Manual:
http://www-307.ibm.com/pc/support/site. ... MIGR-46464

You don't think it is the lcd inverter?

It won't be in there. You cannot buy that piece from lenovo you have to buy the whole lcd which is what they are going to sell you. You usually just have to find a tube that is the same length and it should work.

Humpa · #15 Post by **Humpa** » Thu Jun 22, 2006 3:09 pm

Thanks Paxonator,
I did some more searching online, and I guess I'll give the backlight replacement a go.
lcdpart.com has suitable backlights for $10, so it isn't like it is much of a gamble.
I'm not concerned with the installation - I've had electronic repair jobs and micro soldering classes, etc ...
I was more interested in isolating the problem/defective part.
I guess it still could be the inverter, but it seems more likely that it is the backlight.
Also, it seems that I probably have 2 problems - the other one being a bad or loose cable or connection. I'll have to check around when I have it open, and see what I can see.

T40 LCD Problem

T40 LCD Problem

Who is online