T20 screen blanking

Message

Rex · #1 Post by **Rex** » Thu Dec 01, 2005 4:15 pm

Hi there,

My faithfull T20 is developing a little problem. Upon booting, the screen frequently does not illuminate. Tweaking the screen back and forth on the hinge usually resloved the issue.

Obviously the problem is relativaly minor in that it is a cable connection; probably the cable has fractured.

Is it user replaceble and if so, is this a relatively straightforward job? Can I get a new cable from IBM?

Any advice would be gratelfully appreciated.

Many thanks in advance,

Rex

wireless4laptop · #2 Post by **wireless4laptop** » Thu Dec 01, 2005 9:12 pm

You can connect the line again.

bej98 · #3 Post by **bej98** » Mon Dec 05, 2005 10:31 pm

Hi Rex, I had the same problem with my T21. It gradually got worse over a period of months. Since I could often get the backlight to come back on by torqueing gently on the screen near the hinges, I figured it had to be the cable.

For the T21 the P/N is 27L0490. I ordered it from Westworld Computers (westworldcomputers.com) for $35 and received it in 5 days.

The HMM doesn't talk about this FRU, but if you take apart the LCD display, it's right there. Getting LCD display apart requires that you disassemble the unit pretty thoroughly, but not too difficult. Took about 90 minutes, round trip.

Best Regards,
-Brian

t20user · #4 Post by **t20user** » Thu Dec 08, 2005 8:38 am

I had this issue on my T20 a year ago. I thought I would need a new cable or other part. It turned out it was only a loose connection. I took apart the unit and reconnected the LCD cable and have not had a problem since. Good Luck.

Rex · #5 Post by **Rex** » Sun Jan 01, 2006 12:34 pm

Gentlemen,

Is it some time since I looked at this forum.

Many thanks for your replies. Guess I have no choice but to give it a go.

So I need a manual or is disassembly pretty straightforward?

Rex

Website · #6 Post by **tfflivemb2** » Sun Jan 01, 2006 12:37 pm

Here is the manual that you will need:

ftp://ftp.software.ibm.com/pc/pccbbs/mo ... 2p9631.pdf

Rex · #7 Post by **Rex** » Sun Jan 01, 2006 12:55 pm

tfflivemb2

Thanks for the link. I have just picked up your message on the other forum.

I additionally asked if this is a simple task that the average guy with a 9" hammer and a set of jewelers screwdrivers can can undertake or will I be left with a few extra screws?

I am handy with tools but I have never disassembled a laptop before.

Rex

Website · #8 Post by **tfflivemb2** » Sun Jan 01, 2006 1:29 pm

As I stated in the other thread...it is pretty straight forward, unless there is a problem with your actual backlight. The backlight is within the LCD itself, and IBM doesn't give directions for going that far.

Now, if it is just the cables, then you should be fine (minus the hammer

). I keep a set of jeweler's screwdrivers in my kit at all times.

Website · #9 Post by **tfflivemb2** » Sun Jan 01, 2006 1:36 pm

To keep things simple, we'll just keep the conversation in this thread, as it was your original thread.

Got it; many thanks.

Don't think the back light is going bad. It works just fine, only when switching on, have to open and close the hinge a few times for the light to fire up. During that time, booting happens and when the light comes on, everything is fine. Can even swing the screen and it remains on, which doesn't seem logical if the problem is the connector.

Guess I will dive in a find out.

Rex

Have you checked to make sure that the little switch that tells the laptop that the LCD is closed, isn't sticking? This has been an on and off again problem with some of the older laptops, depending on their total usage.

Rex · #10 Post by **Rex** » Sun Jan 01, 2006 4:49 pm

Hadn't checked that but it's a good idea. However, if that is the problem., I don't see why opening and closing the screen (not totally closing it) would unstick the button.

Usually, I find the backlight comes on when the screen is in about the 160 degree position, assuming that closed is 0 degrees. But this evening, I had to open/close it a few times before it worked.

Rex

Rex · #11 Post by **Rex** » Mon Jan 02, 2006 4:22 am

Have been doing a bit of pre-disassembly investigating and my problem is not the switch.

When I booted, same backlight issue until I wiggled the screen and on it came. Switched off and rebooted to see if the screen remained on or off. It came on. Changed the screen angle and it came on.

However, every time, rather than starting black (backlight not on), then going to the IBM logo, it flashed once for about 0.5 second before the IBM logo. During that brief 'flash' period, the screen was lit very unevenly. But when it works, it's just fine.

Could this be symptomatic of a bigger problem? Screen needing replacing; computer giving up the ghost?

Rex

Website · #12 Post by **tfflivemb2** » Mon Jan 02, 2006 9:49 am

Was that the only time that the screen was unevenly lit? That sounds like the result of the backlight, BUT if it happened only one time, it could have been a result of the pressure on the LCD, hence pressure on the backlight. You might still be ok with the backlight.

I would continue to disassemble and check your connections. Remember that there is also a connection of the the LCD cable to the LCD. This requires removing the LCD from the display case, which can be a little more difficult, so just be very careful.

Rex · #13 Post by **Rex** » Mon Jan 02, 2006 12:39 pm

tfflivemb2

Many thanks for your support and input on this one. The nature of this thread is getting somewhat confusing so I will outline what is happening.

It's a T20 that was brought as a used laptop about two years ago and has been working just fine. i now use a T22 and the T20 is delegated for watching TV with a USB box or DVD's and/or a back-up should the T22 go down.

Recently when booting (about 50%of the time) everything is fine. When up and running, the screen is bright, clear and evenly lit. The other 50% is the problem. When booting, the screen remains black; I don't mean that the back light is on but the pixels are black, I mean black, like the computer is switched off. By opening and closing the screen (no twisting involved) between fully open to almost fully closed, the screen jumps into life at around the 120 degree open position (but this is not repeatable) and everything is hunky dory. Once the screen is working, I can open/almost close it but the dodgey connection cannot be found; it just continues to work.

Today, I tried the little button; it is OK. While the screen was open, I depressed it and the computer hibernated. Release it and the computer woke up, but the screen flashed unevenly for about 0.5 second. Uneven means dark in the centre, brighter at the edges and corner, with horizontal streaking. Then the resume screen came on as normal and everything was fine.

Tried switching off with the screen open. Moved the screen and switched back on. Again, similar flash (0.5 second) before the regular IBM start-up logo appeared. From then onwards, operated as normal.

I still feel the problem is with a connection (back light, ribbon cable, fractured ribbon cable) but there could be a bigger issue that I know nothing about. The problem is only on starting or resuming, I cannot replicate it when the computer is up and running. Could there be something else going down; is the computer coming to the end of its useful life?

As I said before, I guess I will have to dive in a have a poke around.

Rex

Rex · #14 Post by **Rex** » Wed Jan 04, 2006 4:26 pm

Just an up-date.

Haven't fixed it yet, but haven't had the time to open the computer either.

But did talk with IBM and the ribbon cable that may be the problem is no longer available.

Hope my problem is only a loose connection.

Rex

Website · #15 Post by **tfflivemb2** » Wed Jan 04, 2006 6:32 pm

If you do infact need the ribbon cable, I am sure that you can still find it on eBay. IBM just doesn't make them anymore.

Rex · #16 Post by **Rex** » Thu Jan 05, 2006 5:16 pm

Been looking on Google and can find the cable. Hopefully, it should not be too much problem.

Rex

skygodtj · #17 Post by **skygodtj** » Fri Jan 06, 2006 11:59 pm

Skip Google and go right for eBay:

http://search.ebay.com/search/search.dl ... bbon+cable

TJ

Rex · #18 Post by **Rex** » Sat Jan 07, 2006 5:08 am

skygodtj

Thanks for the link; I will bookmark it.

Rarely visit US Ebay, one reason being that many sellers do not seem to want to ship overseas. Here in England, T20 ribbon cables are thin on the ground!

Rex

mcr · #19 Post by **mcr** » Tue Feb 14, 2006 3:44 am

I had a similar problem as this.
Symptoms:
Screen was blank, but output to external monitor worked fine.
If you looked REAL close at the right angle, you could just barely make out some of the screen's contents (in the right light, etc...) - Basically unusable

I took the case apart and checked for a loose LCD connection, but that didn't help at all as it wasn't loose. I'm out of ideas. Also, contrast/brightness keys do not work.

I don't want to do any costly repairs on it though, considering the laptop is not worth that much to begin with. What has worked for you guys?

--Mike

Rex · #20 Post by **Rex** » Tue Feb 14, 2006 4:04 pm

I originally started this thread but have yet to dismantle my screen and check if the problem is a loose connection or a worn cable.

However, I am quite convinced that one of these is the problem. On booting, the screen is frequently totally black, no back light at all. By opening/closing the screen, it suddenly jumps into action. Seem to me like a bad connection or cable rather than anything more sinister.

Rex

mcr · #21 Post by **mcr** » Tue Feb 14, 2006 4:50 pm

Which cable do you mean? I checked the cable that went from the screen to the motherboard and that seemed to check out fine.
It's probably a backlight issue. How do you replace one? I'm a student on a budget, so cheaper is always better (even if it means more labor).
-thanks

Rex · #22 Post by **Rex** » Tue Feb 14, 2006 8:02 pm

In my case, as stated before, I figure the problem is with the LCD ribbon cable, I guess that is the one from the motherboard to the screen.

As for replacing anything, I have never done it but all the manuals are available on the IBM site. I have saved the section relating to dismantling whatever will be necessary to check/replace the ribbon cable. Parts seem to be available on eBay.

I'm not a student and I do like my T20, but there is only so much that I will spend on it. There is no point in throwing good money after bad!

Rex