LCD problems. I'm not sure about the inverter as culprit

[milkensen]

Hello,
I have registered in this forum right now, I'd like to read some advices and comments about this problem, thanks.

It started about two weeks ago, when suddenly the LCD of my Thinkpad T42 went black in the middle of a session. Then, after rebooting I realized that the panel was working again normally. But it lasted only a few minutes more, then the problem came again. At this moment was when I noticed that actually the image was not gone, that it still remained there but almost invisible. The screen was working, but not as expected.

Then I found several info in the Internet, and started to understand what was going on. After collecting as much info as I found, I ended to think that the origin of the problem was the inverter card.

I have to say that this ThinkPad is about 5 years old. Its 15'' screen is maybe its best, and without doubt one of the best LCD panels I've seen. This laptop is at the moment my main PC, so I take much care about it Also, this is the first problem it gives me.

The sympthons:

* As I said, image is there but hardly perceptible. It's like if the backlight were too much dim.
* The system boots normally, but after several seconds/minutes the problem occurs.
* I can work attaching an external monitor (resolution lower, and telling this to the BIOS settings).
* If I press Ctrl + Alt + Backspace the system returns to the login panel (I'm a Linux user), and it comes visible again.

I bought an inverter card on eBay.com, which I had to wait a week for (since it shipped from USA to Spain). Of course, the FRU part was checked at the IBM-Lenovo support page.

I replaced the old one for the new one, without any problem. It was easy. I took special care of reseating firmly the item.

The surprise comes when I can see that the problem remains. Exactly the same one. I blamed to the inverter that was bought on Ebay:
-It could have been damaged during the shipment (although it came very very protected indeed).
-It could be already defective (prior to departure), since I noticed that the date of manufacture was about the same as the one I took out. It could have be part of a 5-year-old Thinkpad, as mine.

The seller on Ebay didn't want to take any money from me when I told him that the inverter was defective and didn't work. He, wise and reasonable, ordered a complete refund of the payment in Paypal. These gods are really cheap, but I really didn't expect this behaviour. Even, he told me that it wasn't neccesary that I'd ship the inverter back, since I say it's defective... Just polite? His policy? Smart and clever, as seller? Maybe he knew it?

Since there is one possibility that the problem was the inverter indeed, I've ordered a new one to IBM Service Parts here, in Spain. I think that peope should consider that option firstly, since the part isn't expensive at all; for this FRU, less than 9 € (shipping costs apart), that is..., cheaper than eBay. However, the problem is the 4-week delay they talk about when ordering on line. It seems the same from another countries from the European Union.

Actually, I don't have any idea whether the inverter card is the culprit or not, just that I no have any reason (sympthom) to blame to another part of the LCD (like the backlight bulb) or wherever...

What I've tried at the moment is, obviously, the simplest, cheapest:

-Discard software problems; easy since nowadays everyone can run (boot) another Operating System from the CD-ROM (Linux Live CDs)
-Change the inverter card. Reseat plugs properly.
-Check the BIOS settings. There were already pretty conservative (as LCD bright set to "normal").
-Update the BIOS (and the Embedded Controller program). Never done this into this computer. Now is updated, but the problem still remains as at the beginning.
-Order a real NEW inverter card (from IBM FRU parts). Now, pending of results with this via.

-I don't want to think by now into replacing the whole LCD panel, or buying a backlight (I doubt I could change it successfully).

I can work with the laptop through two methods:
-External monitor (CRT) attached --> worse because I loose a lot of resolution (downgrade to 1024x768)
-MY TRICK!!!: SET THE BRIGHTNESS LOWER WITH THE THINKPAD BUTTONS; IF I MAINTAIN THIS SET UNDER THE RANGE AVERAGE, WITH THE CORD ATTACHED, THE LCD SURPRISINGLY WORKS FINE. DISADVANTAGE: MY EYES END UP A BIT MORE TIRED. ALSO, IN BATTERY MODE, THE LCD REMAINS ALL THE TIME (OF CHARGE OF THE BATTERY), SINCE THE BRIGHTNESS IS ADJUSTED TO LOWER VALUES AUTOMATICALLY.

But since the latest is not a definitive solution, I'm pending of it by now.

If someone has another diagnostic or impression, or just want to ask me something, I'd be pleased anyhow.

Regards

[ajkula66]

Welcome to the forum!

Has your LCD been reddish/pinkish on initial boot, or when running on battery prior to this last episode?

[milkensen]

Welcome to the forum!

Has your LCD been reddish/pinkish on initial boot, or when running on battery prior to this last episode?

Thank you.
No, never!
Nops. Not at all.

Colours (when watching) are okay.

[GACrabill]

This won't help determine where the problem is, but it is interesting.

I know of an older R31 that has to have the brightness down one notch from the maximum to prevent the light from shutting off. It has been this way for at least 3 years and still works fine with no pink hues. I don't know why it acts this way but the owner is happy that it always works fine as long as the brightness level is at least one notch lower than the maximum.

[sparta.rising]

Sorry I didn't read all the way through your post, but it could be the solder connection to the CCFL tube.

[RealBlackStuff]

It would also help if you give us the 7-character TYPE/MODEL, like 2373-MU5.
Put that in your signature (see mine) for future reference.

[milkensen]

How I could discover whether the issue it's what you say, the soldered joint of the light tube (apart from taking to pieces the LCD panel)? Is there a way? I'm afraid there isn't.

Another thing I want to say (for general information) is the weird communication (by email) I took with the support from IBM here in Spain (IBM Parts):
-As I've already said, I recently ordered them on line the part FRU 93P4161. Okay.
-They emailed me confirming the order bla bla... Okay.
-Next day in the morning, I directly went to the bank they had the account, and paid them.
-The same day, they emailed me again, this time wasn't a robot, but one person. She said that they haven't in stock at the moment the FRU part mentioned, which would mean a gap of about four weeks, since they would have to ask for the piece. Okay, nothing new until now. But then she informed me that nevertheless they had in stock its "replacement" ("substitute") (in Spanish talked about "sustituta"), the FRU part 39T0359 at the same price. This statement was what made me somewhat confused . Then, also she asked me for confirmation to follow with the buying (probably they still didn't know the payment have been already done..).
-Next I emailed them replying that of course the buying was continuing, between other things because I'd already made the payment. Also, I asked her to clarify what she said in the previous email, concerning to that other FRU part inverter: basically, I asked for a confirmation about its compatibility.
-It comes the weekend in the meantime. Monday morning they emailed me again, just to say that my ordering has been processed, and now pending of shipment, which is coming into the next two days. At this point, I got absolutely confused
-Let's see the issue as funny: 1st-they did not reply to my question. 2nd-they're shipping me something, but I do not have idea about which could be!!! (whether one or another FRU part) 3rd-If they talked about 2 days now, it's supposed that the FRU part was which one I didn't asked for 4rd-Well, whichever would be, I'll take it and first will assemble it and then we'll see...


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T42 2373-JXG
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[milkensen]

Fresh news!

Shipment arrived today. Messenger to home. I accepted the package, signed, in spite of the papers attached to the pack indicated clearly that the FRU part shipped was the 39T0359 that they talked about in their email (as a replacement...). Even, one of the piece of paper said something as "replacement for the FRU's 93P". Strange for me. Right now I deduce that when they asked me confirmation to continue the ordering, they was planning already into sending "the replacement FRU part", not the asked one.

The worse of all is that the replacement does not solve the problem either. I've just tried it this evening. Also, this inverter comes with a sticker that says "Serviceable used part". So, I don't really know what to think... Symptoms are similar: the unit starts and works fine, but after a few minutes (this will depend on the brightness level set) LCD goes dark although the unit is still running as nothing different were happening.

Now, I don't know if telling to IBM Service Parts of picking the pack back, and waiting for about four weeks, until the original FRU part comes (this supposing they would accept to return this inverter...)

Facts are that I have a LCD panel attached to its unit that does not work, that I have here at home three inverter cards, two of them are supposed to be able to work fine, but none of them is capable of solving the problem. Maybe I should think of another reason for the problem, but I no have idea..., even if it worth to continue for so long trying,waiting, trying again, ... wasting money, time, and efforts. If at least I knew where the problem is, if I had any clue, experience... It could be the backlight bulb, some cable, etc.
On the other hand, if I end up buying another LCD and the problem would remain there... Uff!

Tomorrow morning I'm going to call to IBM and we will see...

[RealBlackStuff]

"Serviceable used part" is either a customer return OR a refurbished item. It's definitely NOT new.

[ajkula66]

IBM will not let you return the part. At their discretion they're allowed to substitute FRU numbers, as well as to supply "serviceable used" parts.

Chances are, the inverter wasn't your problem to begin with.

Good luck.

[milkensen]

"Serviceable used part" is either a customer return OR a refurbished item. It's definitely NOT new.

So.., which means that I'm like at the beginning: even don't know where is the problem.
At least, not absolutely sure that the inverter could not be.

[milkensen]

IBM will not let you return the part. At their discretion they're allowed to substitute FRU numbers, as well as to supply "serviceable used" parts.

Chances are, the inverter wasn't your problem to begin with.

Good luck.

Thank you.
But which place to point to?
With this IBM method (of servicing) I'm not even completely sure of discarding the inverter.
If at least I had some list of possible causes..
May you suggest anyone, please?

Maybe I should start to think in a whole LCD replacement, but even in that way, it could be a problem focused into the mainboard, a conection somewhere, etc.

[kulcousy]

Can an inverter be tested for voltage out? That shouldn't be too hard. Of course the circuit would be hot but, worth a try.
Also, I have had lcd's on 2 machines that blanked when a disk drive ran. I checked all the cables and connections. As I recall one lcd turned out to be bad, the other never has been resolved but maybe now I'll try swapping the display