A31p LCD Problem, replaced multiple parts with no luck

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wakeskate · #1 Post by **wakeskate** » Fri Apr 04, 2008 11:13 am

For whatever reason, I can not get the lcd bulb to light up on my LCD screen.

One day I woke up the computer from sleep mode and it blinked and went dark. I can still see the faint images even from the initial IBM screen after I start it, so I don't think it's a software related issue. It works flawless with an external monitor.

I replaced the following, with the bulb first.

Bulb - didn't fix problem, then bought inverter card, didn't fix problem so i bought a new LCD to start fresh.

LCD - used from ebay, but the light bulb works, as I have tested it with a differnt inverter card.

LCD Cable - new from IBM

Inverter Card, twice. - one new from IBM and one from Global PC parts.

The motherboard was replaced under warranty about 2 years ago.

I want this thing to be mobile again!

Any suggestions? I dug around for awhile in the forums, so I have an idea, but would like to hear your thoughts.

Thank you,

Kyle

sjthinkpader · #2 Post by **sjthinkpader** » Fri Apr 04, 2008 12:08 pm

Did you checked all the fuses on the MB?

virge · #3 Post by **virge** » Fri Apr 04, 2008 12:09 pm

wakeskate wrote: LCD - used from ebay, but the light bulb works, as I have tested it with a differnt inverter card.

If your cable and inverter are both new, the LCD is a likely culprit. It may be a silly question, but is your replacement LCD UXGA? While swapping panels in A2* series, I noticed that mismatched LCDs and cables would cause what you describe above.

If thats not it, maybe you have a stuck lid switch?

Okay, I'm done guessing.

wakeskate · #4 Post by **wakeskate** » Fri Apr 04, 2008 2:08 pm

I have not checked the fuses. Where are they located? Do I need to take off only the keyboard to get at them?

My laptop is an A31p, 2653-H4U

Here is my current LCD setup with cable and inverter
15inch SXGA+ TFT
3 LCD cable assembly 15in SXGA+ 27L0682
5 Inverter card 26P8132
6 LCD panel, 15in SXGA+ (Samsung) for A30 05K9965

Here is what it came with
15inch UXGA IPS TFT
3 LCD cable assembly 15in UXGA IPS 27L0683
5 Inverter card for IPS 26P8133
6 LCD panel, 15in UXGA (DBU) 05K9967

I am pretty sure it's not the LCD because it was working fine when the bulb was being powered from a different inverter card.

Tell me more about these fuses.

Thank you!
Kyle

wakeskate · #5 Post by **wakeskate** » Fri Apr 04, 2008 2:09 pm

ps. I pulled the lid button up as far as I could too and nothing changed. Is there anything else I can do with that? I don't think that's it either.

ajkula66 · #6 Post by **ajkula66** » Fri Apr 04, 2008 2:54 pm

Sounds to me like a motherboard issue...and I hope I'm wrong.

wakeskate · #7 Post by **wakeskate** » Fri Apr 04, 2008 3:22 pm

...sobbing.... they just don't make the keyboards like these any more with the new laptops.

Is there anything else I can do to check make sure it's the motherboard? Anyone who specializes with this?

ajkula66 · #8 Post by **ajkula66** » Fri Apr 04, 2008 3:29 pm

Agreed on the keyboards...and a lot else...

You can contact forum member jamiphar (James) who repairs all types of ThinkPads, and has experience with A31p units, he takes care of my personal A31p stock, and would recommend him highly.

Good luck.

wakeskate · #9 Post by **wakeskate** » Fri Apr 04, 2008 7:55 pm

anyone have any other ideas?

Thank you for the replies!

sjthinkpader · #10 Post by **sjthinkpader** » Sat Apr 05, 2008 1:53 am

wakeskate wrote:I have not checked the fuses. Where are they located? Do I need to take off only the keyboard to get at them?
...

There are close to twenty of these all over the board. The backlight fuse should be close to the LCD connector. Most are labeled with Fx markings. If you are not handy in replacing them, likely is best to leave it to Jamiphar.

virge · #11 Post by **virge** » Sat Apr 05, 2008 11:27 am

wakeskate wrote: I am pretty sure it's not the LCD because it was working fine when the bulb was being powered from a different inverter card.

If your LCD is lighting up, that means the inverter and backlight is working. However, it doesn't mean that the LCD/cable/motherboard are compatible. Are you by any chance trying to install an UXGA screen using SXGA cabling? That might cause a blank screen situation (it did when I tried it on my A22 and A22P systems). What are the FRUs of the replacement screen and cable you bought?

sjthinkpader · #12 Post by **sjthinkpader** » Sat Apr 05, 2008 12:03 pm

Since he can see a faint image on the screen, he has the correct cable.

virge · #13 Post by **virge** » Sat Apr 05, 2008 7:16 pm

sjthinkpader wrote:Since he can see a faint image on the screen, he has the correct cable.

You're absolutely correct if OP is seeing the faint image. He says there is a faint image on the original LCD, but we need him to come back and confirm whether he's seeing that on the replacement LCD as well.

wakeskate · #14 Post by **wakeskate** » Mon Apr 07, 2008 8:24 am

Hi everyone. Thank you for your replies.

I listed the old and new setups for my LCD. I CAN see the faint image on both setups- SXGA and UXGA. All of the FRUs are listed next to the item descriptions in one of my previous posts. My new LCD is SXGA, while my old was UXGA. I replaced the cable and inverter to match the SXGA LCD, so I shouldn't have any problems there.

Again, the new LCD lights up because I connected it to a different inverter, which was on a different computer. So I know it's good. The cable is brand new from IBM, I hope that is good (it should be). The inverter card is from global pc parts (bought from Ebay) and I called to talk to someone and he said that he tested that part for sure and knows that it is a working inverter. Since my inverter from IBM and this one from global pc parts don't work, I think there is something with the Motherboard.

I am going to check fuses tonight. Does anyone have a picture of where they are? I am fine with electronics and will check continuity tonight!

Thank you everyone and hope to hear more.

Kyle

sjthinkpader · #15 Post by **sjthinkpader** » Tue Apr 08, 2008 1:56 am

Here you go:

A31 Fuse Map

If it indeed is a fuse problem, and you find which one it is; please post it here.

wakeskate · #16 Post by **wakeskate** » Tue Apr 08, 2008 7:55 am

Will do! Thank you!!!

virge · #17 Post by **virge** » Tue Apr 08, 2008 5:06 pm

Good luck on that project Kyle. It sounds like everything other than the motherboard has been ruled out.

Edit: You might want to read this post: http://forum.thinkpads.com/viewtopic.php?t=59647

Its regarding a T4x machine, but the information about blowing fuses just by checking them might apply.

wakeskate · #18 Post by **wakeskate** » Wed Apr 09, 2008 9:30 am

OK. I wanted to check last night, but I couldn't get the expansion bays out. ( not the CD drive itself, but the metal shields) I am assuming that the fuses are on the underside of the motherboard and everything needs to come out.

I don't mean to disappoint everyone, but I am going to think twice about taking apart the whole computer. I might give in to the dark side and just go buy another one and keep this as a desktop computer. It urks me because I have fixed other stuff before and can't stand to let something sit there broken.

I probably should talk to Jamiphar.

sjthinkpader · #19 Post by **sjthinkpader** » Wed Apr 09, 2008 9:57 am

There are quite a few screws on the two Ultrabays. The right side Ultrabay has the 4 screws underneath holding the two CDCs.

The general sequence is to work counter-clockwise from the right side Ultrabay, then PCMCIA slot, Fan, left side Ultrabay.

Assembly is the reverse starting from the left side Ultrabay. Remember to make sure you have the release tab engage the pull levers before you go to the next step.

A step by step in in the long post in this chain.
http://forum.thinkpads.com/viewtopic.ph ... ht=antenna
After removing the 4 major internal assemblies:
1. Remove all the connector threaded studs in the back, three screws. (a metric hex driver helps here).
2. Remove two screws holding the MB, upper right and lower left.
3. Remove the speaker wires. Remember how the two metal pieces go.

Take some pictures how things go so you can reference them later.

Jamiphar is the other alternative.

sausage888 · #20 Post by **sausage888** » Wed Apr 09, 2008 5:05 pm

It is my impression that the inverter's only purpose is to light the CCFL. My inverter sometimes loses contact with the cabling to the CCFL and the screen goes dark, but I can see images on the screen with a flashlight (same symptoms as burnt out CCFL). I pull the bezel off and reseat the inverter again (live, so I can see when it contacts) and once it lights the bulb - it works fine for months.

sausage888 · #21 Post by **sausage888** » Wed Apr 09, 2008 5:09 pm

I also though to mention about the tiny little on/off switch which is triggered when you close the lid of the laptop. I have had my tiny switch get stuck to off. (just to the left of the "A31" on the bezel)

wakeskate · #22 Post by **wakeskate** » Fri Apr 11, 2008 8:08 am

Thank you sjthinkpader.

sausage888, I also thought about the cabling. I have moved and wiggled the wires going to the CCFL and that doesn't do anything. I also pulled up and played with the backlight switch for a while. If I do it live, the computer will go into sleep mode, so I think the switch still works properly.

Man I like the computer and hate to see it go, but at some point my sanity is more valuable than it.

sjthinkpader · #23 Post by **sjthinkpader** » Fri Apr 11, 2008 10:07 am

wakeskate wrote:...
Man I like the computer and hate to see it go, but at some point my sanity is more valuable than it.

Yes, sometimes you just have to set it aside and call it a day. I hope you did finally get the MB out.

These A31s along with T23s and T30s are still staying in circulation. Much tougher than the later T4x and T5x.

wakeskate · #24 Post by **wakeskate** » Sun Apr 20, 2008 12:20 am

well, I broke down and bought a new thinkpad. I hope to have the same life out of the new one as I did with this A31p.

Is anyone interested in buying the parts from me for the monitor? I am sure all of the parts are fine as I've seen the display light, the inverter was tested, the other inverter new from lenovo, and one harness is new with the other in fine shape. I will be using an external monitor from now on with this machine.

Let me know if you want more info on the screen, two harnesses and two inverter cards.

Thanks everyone,

Kyle

kosse · #25 Post by **kosse** » Sun Apr 20, 2008 5:26 am

I'm sorry you had to give up on your A31p. That said, I still feel a bit like a vulture coming to a carcass since I could not help in any way but I am really in need of a inverter card since I'm having screen related problems too.

I sent you a PM about the matter.

cbraswel · #26 Post by **cbraswel** » Sun Nov 23, 2008 6:59 pm

I had this same problem with an A31. Luckily I had several A31s available, so I could swap LCDs without having to buy parts. After A couple of LCDs and no luck I started searching for a solution and ended up here. In my case the fuse was the culprit. It was the F5 fuse on the bottom of the motherboard, underneath the LCD cable connector. No need for a diagram, look for the F5 stamp. Replaced the fuse and works good as new.

Thanks for the good suggestions!

#27 Post by **rkawakami** » Sun Nov 23, 2008 7:10 pm

@cbraswel: Welcome to thinkpads.com!

For future reference, did you simply take the F5 fuse off one of your other systems or were you able to determine what the fuse's rating was and purchase a new one?

cbraswel · #28 Post by **cbraswel** » Sun Nov 23, 2008 8:00 pm

I had a ruined board so actually I pulled the F5 fuse off the bad board and soldered it piggyback on the bad fuse. There is plenty of clearance between the board and the bottom panel in that area.

#29 Post by **rkawakami** » Sun Nov 23, 2008 8:06 pm

Okay, thanks for that info! I was just curious in case I (or somebody) else runs into the same type of issue. Mouser.com and digikey.com both sell surface mounted fuses so I was hoping that you might have a part number or current rating. One of my A31p systems also seems to have a problem with the backlight but I haven't taken the time yet to isolate it to the lamp, inverter, cable or fuse.

matermark · #30 Post by **matermark** » Thu Feb 26, 2009 8:46 pm

Did anybody ever find out what rating the F5 fuse was, and is this the only fuse on the MB for the LCD?

A31p LCD Problem, replaced multiple parts with no luck

A31p LCD Problem, replaced multiple parts with no luck

Re: A31p LCD Problem, replaced multiple parts with no luck

Found the correct fuse

Re: A31p LCD Problem, replaced multiple parts with no luck

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