A31 LCD backlight not working

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xcandrew · #1 Post by **xcandrew** » Sun Apr 27, 2008 12:33 am

The backlight on my A31 with the 15" SXGA IPS screen stopped working and I am seeking some advice about how to fix it. For about two weeks before it blacked out completely, the screen gradually flickered more and more, became dimmer, and blacked out temporarily once (revived when I restarted the computer). When it finally blacked out for good, the black swooped in from the left and right sides of the screen. The display can now be barely made out with some external light directed at the screen.

I did a google search read about how a pink screen is often an indicator of a failing backlight. My A31 never had this symptom, so I guessed it was the LCD inverter. I got an inverter off ebay, P/N 26P8132. When I opened up the bezel, I found out that my replacement inverter was the wrong part. The part in my A31 is P/N 26P8129/FRU 26P8133. Doh! I should have opened it up before buying the part. Apparently the replacement that I bought is for the 14.1" and non IPS 15" screens.

I installed the 26P8132 inverter anyway to see if it would work. It plugged in fine, but doesn't work. A previous post in these forums suggested that an inverter for the non-IPS screens might operate at a reduced brightness, but my screen isn't showing any signs of light.

What should I do next? Should I try to replace the backlight because the 26P8132 inverter (maybe) should have lit up the screen at least dimly? Or should I try the correct inverter next? Unfortunately, the correct inverter is a lot pricier on ebay than the incorrect one that I got ($35 vs. $10), so I'd like the expertise on these forums to help me make a more informed choice.

I hoping it isn't a more serious problem (motherboard?) because I've had my A31 since 2002 and it has XP Professional and MS Office and other software that I probably couldn't legally transfer to a new PC, and has otherwise been near perfect...

sjthinkpader · #2 Post by **sjthinkpader** » Sun Apr 27, 2008 6:43 am

It could be any of three items, CCF, inverter and a fuse on the MB. The non-IPS inverter should have worked as you indicated. Now you should try a different panel or check out the fuses (I don't know which one).

I posted a fuse map inthis thread.

http://forum.thinkpads.com/viewtopic.php?t=60211

polo · #3 Post by **polo** » Mon Apr 28, 2008 10:21 am

Hi,

I had the same problem with my A31p but it got fixed on warranty. If you have a dim image on the screen and you get a normal picture with an external monitor, it is either the CCFL tubes or the inverter. As far as I know, there is no way to know which without trying each. Seems to me that when I had the machine apart to install a new MB a little while ago, I saw the inverter but don't remember seeing the CCFL tubes. I just checked the A31 maintenance manual and could not find anything about the CCFL tubes so I'm pretty convinced they are mounted internally in the LCD panel which makes them a bit more of a pain to change yourself.

When the same thing happened on my Sony laptop a few years ago, I gave it to my brother and he mailed it off to a place that did flat rate laptop screen repair for $150. It has worked fine ever since. You might consider this option.

Hope this helps.
Polo

xcandrew · #4 Post by **xcandrew** » Mon Apr 28, 2008 4:48 pm

sjthinkpader wrote:It could be any of three items, CCF, inverter and a fuse on the MB. The non-IPS inverter should have worked as you indicated. Now you should try a different panel or check out the fuses (I don't know which one).

I posted a fuse map in this thread.

http://forum.thinkpads.com/viewtopic.php?t=60211

Thanks for the reply. I don't have another panel to try (expensive, I'm guessing) and checking the fuses doesn't require spending more money yet, so I'll try to do that first. I've never disassembled a computer, much less a laptop, so hopefully, I'll be able to understand the step-by-step directions to access the motherboard. Does "KB" in "KB screw" refer to keyboard? Are the fuses labeled with the ratings, so that I would be able to find and order an identical one? Or would it be really bad to just short a bad fuse with solder if I find one?

ajkula66 · #5 Post by **ajkula66** » Mon Apr 28, 2008 4:53 pm

You also may want to contact forum member jamiphar (James) who offers all types of laptop repairs and has plenty of experience on A3x units. He maintains my personal A31p stock.

Good luck.

#6 Post by **rkawakami** » Mon Apr 28, 2008 5:10 pm

xcandrew wrote:I've never disassembled a computer, much less a laptop, so hopefully, I'll be able to understand the step-by-step directions to access the motherboard.

I'm assuming you have a copy of the Hardware Maintenance Manual (HMM) for your system:

http://www-307.ibm.com/pc/support/site. ... 39796.html

xcandrew wrote:Does "KB" in "KB screw" refer to keyboard?

Not sure where you are referencing this term as it does not appear to be in the A3x HMM, but that sounds like a good guess.

xcandrew wrote:Are the fuses labeled with the ratings, so that I would be able to find and order an identical one?

Generally not. There may be a letter or number code on them which sometimes can be used to figure out what the current rating is, given a thorough search at places like mouser.com or digikey.com.

xcandrew wrote:Or would it be really bad to just short a bad fuse with solder if I find one?

Probably yes. The fuse blew for a reason (mostly, too much current being drawn; less so for it being a mechanical break due to a drop or impact). If it was a temporary short and not likely ever to happen again, then using a solder bridge across the bad fuse would certainly "fix" the problem. However, if that short or excessive current draw happens again, more extensive electrical damage could result. Worst case scenario is your system catches fire.

xcandrew · #7 Post by **xcandrew** » Tue Apr 29, 2008 4:13 am

I read through the first third of the Hardware Maintenance Manual and it made me think of two things:

1) Page 58 "LCD-related symptoms" states that horizontal or vertical lines displayed on LCD points to a LCD assembly problem. I should have noted in my first post that the flickering was a horizontal line flickering. Does this clue suggest that the CCFL backlight is more likely to be the problem, or does a bad system board fuse produce similar lines?

If I need a CCFL, is there a difference between CCFLs for the IPS and non-IPS screens (since I already made a mistake on the inverter)? Would the following work? http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0062714325

2) Page 57 "Beep Symptoms". Likely unrelated to screen problem, but I thought that I'd ask. I didn't realize that there was a code to beep sounds. I have noticed random single longish beeps infrequently the last, I'd say, two years or so (bought the A31 new in 2002), but with no consequences that I can tell. It doesn't quite fit any of the beeps listed on that page, unless the "One beep and a blank, unreadable, or flashing LCD" doesn't have to happen at the same time. What kind of problem might this point to? The screen is the only actual problem I've had with my A31.

Admin edit: Shortened URL to prevent horizontal scrolling

xcandrew · #8 Post by **xcandrew** » Wed Apr 30, 2008 9:49 pm

If I'm getting an open circuit voltage of about zero at the connector of the inverter where the screen plugs in, can I assume that the CCFL is probably not causing the problem? Just want to confirm that I need to open up the computer to check the fuses.

#9 Post by **rkawakami** » Wed Apr 30, 2008 10:24 pm

I hope you aren't using a regular multimeter to read the voltage being output from the inverter... it's a couple of thousand volts

. You're probably in not that much danger since when I tried running an inverter without any load (i.e., a CCFL), it basically self-destructed.

You might want to try this:

http://forum.thinkpads.com/viewtopic.php?t=48910

Also check your lid switch as if it's stuck down, then that will cut off power to the inverter.

xcandrew · #10 Post by **xcandrew** » Fri Sep 05, 2008 9:56 pm

OK, I'm still trying to fix this problem. I was using an external CRT monitor until early July when the CRT died. Since then, I've been shining a desk lamp at the screen, which is really annoying and obviously doesn't work very well.

I don't think I should open the main body of the computer to check the fuses because I'm afraid of static discharge damage. I bought one of those static-control wrist straps, but I'm not sure how to use it correctly. It's supposed to be clipped to a grounded work surface, but what constitutes a grounded work surface? The stuff I'm reading on the internet is not specific enough to give me confidence, and I would feel better seeing how the professionals or other experts have their work stations set up. Is there a way to improvise a work station cheaply with readily available materials (rubber car floor mats, Al foil, scrap metal, etc.)?

Also, the HMM says something about not re-using the screws because they're one time use and would come loose - darned if that's another obscure thing that's going to take time (and $$) to track down.

I'm still not sure where the problem lies. The thread about the neon lamp was interesting, but it seems to be conclude that a neon lamp would not be diagnostic.

I would send my computer out to jamiphar as suggested above, but he didn't respond to PM or email in early July. I'm assuming he's out of this business or on a really long vacation. Has anyone heard of MoniServ and tried their CCFL replacement service?

http://www.moniserv.com/lcdpartsnet/panelnet.htm

It seems reasonable at $75, though it might not the problem with my computer. However, my other main alternative seems to be coming down to buying a new laptop. This would probably be more than I can afford considering the cost of a comparible laptop (I paid $1800+ new for my A31 back in the day) and software that I paid for that is linked to my computer (ArcView, Office, etc) that I'm assuming is not transferable to another computer. Any more suggestions?

tim S · #11 Post by **tim S** » Sat Sep 06, 2008 9:50 pm

Check out this auction on Ebay 280263523655. Pick up a tube for your screen 15.1, I think. When you get the tube remove the bezel from around the screen and plug the tube into the inverter, be very careful they are fragile and snap easily, and see if it works.
Tim S

proaudioguy · #12 Post by **proaudioguy** » Sun Sep 07, 2008 11:17 am

tim S wrote:Check out this auction on Ebay 280263523655. Pick up a tube for your screen 15.1, I think. When you get the tube remove the bezel from around the screen and plug the tube into the inverter, be very careful they are fragile and snap easily, and see if it works.
Tim S

CCFL tube int he A31 doesn't plug into the inverter. There are wires soldered to the tube. The other end of the wires plug into the inverter. New tubes would be unlikely to come with wires as there would be no way to install the tube without removing the wires anyway. If he's afraid to open the computer I don't think your solution is going to work for him.

To the OP, if you are afraid to open the computer, send it to Jamiphar for a CCFL replacement or at least to evaluate it.

If you decide to sell the computer, let me know.

sjthinkpader · #13 Post by **sjthinkpader** » Sun Sep 07, 2008 12:19 pm

xcandrew wrote:...
I would send my computer out to jamiphar as suggested above, but he didn't respond to PM or email in early July. I'm assuming he's out of this business or on a really long vacation. Has anyone heard of MoniServ and tried their CCFL replacement service?
...

There is a repair place called Hammerhead in Chico, CA that had been in business for a long time. I had bought parts from them before and getting ready to send them a T43 MB for repair. You can try calling them or buy a repair service coupon on eBay.

sparta.rising · #14 Post by **sparta.rising** » Sun Sep 07, 2008 12:50 pm

proaudioguy wrote:CCFL tube int he A31 doesn't plug into the inverter. There are wires soldered to the tube. The other end of the wires plug into the inverter. New tubes would be unlikely to come with wires as there would be no way to install the tube without removing the wires anyway. If he's afraid to open the computer I don't think your solution is going to work for him.

If you actually looked at the auction that he was refering to, you'd see that the seller is indeed selling CCFL tubes with wire and harness pre-soldered. Although the seller has zero feedback and just joined a week ago, which is a little questionable. The price however is very reasonable.

fasterbybike · #15 Post by **fasterbybike** » Sun Sep 07, 2008 9:58 pm

And the Ebay auction was for a 317mm CCFL. That won't fit a 15" LCD. You need a 307 or a 310mm CCFL.

proaudioguy · #16 Post by **proaudioguy** » Thu Sep 11, 2008 12:26 am

sparta.rising wrote:
proaudioguy wrote:CCFL tube int he A31 doesn't plug into the inverter. There are wires soldered to the tube. The other end of the wires plug into the inverter. New tubes would be unlikely to come with wires as there would be no way to install the tube without removing the wires anyway. If he's afraid to open the computer I don't think your solution is going to work for him.
If you actually looked at the auction that he was refering to, you'd see that the seller is indeed selling CCFL tubes with wire and harness pre-soldered. Although the seller has zero feedback and just joined a week ago, which is a little questionable. The price however is very reasonable.

You and I must be looking at different auctions because I just checked again and there is no wiring harness mentioned and the seller has a feedback of almost 18,000.

madmaven · #17 Post by **madmaven** » Sat Nov 08, 2008 8:57 pm

I have an A31 with a SXGA display that has gone dark. you can see it with a flashlight and it is just fine on an external monitor.
I got an inverter with the same number as the original on it and that did not light the screen,
so rather than mess with the touchy hard to find CCfl bulb I want to just change the entire display at the hinges.
I've done this before with some success.
Can I use a XGA display from an A31 or do I need the SXGA like the original?
Dont want to invest in an XGA LCD if it wont work.
Also how hard is it to find and fix the fuse if that is the problem
thanks Madmaven

ajkula66 · #18 Post by **ajkula66** » Sat Nov 08, 2008 9:40 pm

You can use the XGA display, obviously with proper cable and inverter. The resolution will change, but if you're comfortable with it, no problem.

I happen to have an almost perfect 15" XGA LCD complete with lid and everything else...PM me if interested.

xcandrew · #19 Post by **xcandrew** » Sun Nov 09, 2008 1:44 am

I'm the original poster... I ended up sending my screen to Moniserv to get the backlight replaced, and that fixed the problem.

However, I noticed spots in the screen after I got it back. I ended up taking apart the screen in an effort to clean it. Turned out to be spotting on the silvery reflector at the very back of the screen... the repair person must of dripped something on it. Now I kind of feel silly for sending it in, because I ended up taking the whole thing apart anyway. The CCFL replacement, including the soldering part, wouldn't have been that difficult for me. The main problem is that it is a challenge to keep dust out when working on it. It would have been nice to have access to a clean room like the one I used to work in my old job in the semiconductor industry...

Still, I would recommend sending your current screen to Moniserv for CCFL replacement if you want to keep your SXGA display. Do you know if it is a Flexview screen?

#20 Post by **RealBlackStuff** » Sun Nov 09, 2008 7:17 am

Flexview screens are made by Hyundai and have a marking BOE/Hydis (or similar) on them somewhere.

How much does Moniserve charge?

xcandrew · #21 Post by **xcandrew** » Sun Nov 09, 2008 4:57 pm

RealBlackStuff wrote:Flexview screens are made by Hyundai and have a marking BOE/Hydis (or similar) on them somewhere.

How much does Moniserve charge?

My Flexview was marked IDTech, made in Japan, and the UL Certification number matches that of "CMO Japan LTD".

Google search result says: "International Display Technology (IDTech, a subsidiary between Chi Mei Optoelectronics Corporation and IBM Japan, located in Yasu (Japan)"

Moniserv charges $75, and you pay shipping both ways.

http://www.moniserv.com/lcdpartsnet/panelnet.htm

ajkula66 · #22 Post by **ajkula66** » Sun Nov 09, 2008 5:07 pm

That's a LOT of money for a job NOT done right...

xcandrew · #23 Post by **xcandrew** » Sun Nov 09, 2008 6:15 pm

Well, it's less than the $150 that jamiphar would have charged. Maybe he would have done a better job, but like I said, I couldn't get a response from him in over several months. Bad service (maybe some bad luck too?) is better than no service - unless you think it's better to use a desklamp over the screen to try to make out what's on the screen like I had to do for several months.

ajkula66 · #24 Post by **ajkula66** » Sun Nov 09, 2008 6:38 pm

Roughly $100 for an LCD that I would have to open afterwards compared to a job done right for $150 is a no-brainer for me. I don't mind paying for service that I'm satisfied with. But that's me.

I would've asked for my money back, and if that wouldn't be appropriately addressed, they would get a LOT of negative advertising...once again, that's me.

xcandrew · #25 Post by **xcandrew** » Mon Nov 10, 2008 12:34 am

You missed the part about the non-availability of the $150 job. I went with the only repair service that I could find that was actually available. I didn't see any other repair service suggestions here or elsewhere on-line.

I didn't give them the opportunity to make it right, so I'm not going to blame them. I didn't want to have to send the screen back and wait another week or two, and I was finally curious enough to take it apart myself. Other repair services probably don't get it right all the time either, and Moniserv probably gets it right most of the time. I don't have enough data to judge.

jamiphar · #26 Post by **jamiphar** » Wed Nov 12, 2008 6:05 pm

@ xcandrew

I'm sorry, but I don't recall ever receiving a message from you. I may have accidentally deleted it. Just so you're aware, the $150 price includes a shipping box, all shipping costs, and a one-year warranty.

Feel free to contact me again with any questions you have, my e-mail address is james@arndtcomputer.com.

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