T30 Display and power problem

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#1 Post by **RealBlackStuff** » Wed Jan 24, 2007 5:46 am

While re-assembling my T30 (2366-87G) and trying it out, I inadvertently shorted the inverter board against the metal frame of the LCD-screen. A small wisp of smoke, and that was it!
I replaced the LCD-cable and the inverter. When I boot up, the laptop's fan and hard disk start spinning up, the control lights on the LCD-cable and inverter light up, but after a few seconds it powers down by itself.
I then have to remove power (either battery or mains) for a few seconds, then reconnect, and she spins up, but again powers down after a few seconds, etc..
But when I disconnect the LCD-cable from the mobo, connect an external monitor, and then start her up, everything works perfectly. This means mobo and graphics card are still OK (so far).
Using my docking-station (2631) makes no difference, except I can easier connect keyboard, mouse and monitor to it.

Those symptoms either point to a defective LCD-screen (hope not, the backlight still seems to come on in that short spin-up), or there is a problem with one or more condensers or something on the motherboard.
Anybody ever had the same problem, and how did you solve it?
Thanks for any info.

PS: My T30 has an (undocumented) Hitachi LCD panel P/N: 11P8292, FRU: 11P8297 (150nit).
Which 14.1" XGA panels would be compatible (from e.g. T2x or others) if I do need a new one?

#2 Post by **rkawakami** » Thu Jan 25, 2007 4:15 am

Based upon your description of the release of "magic smoke" from the inverter and how the system appears to work fine if the LCD ribbon cable is removed, you may have a problem with the cable or inverter or motherboard.

Try this: with the ribbon cable plugged into the motherboard, just remove the inverter and see if the system can run normally. If so, that tells you that the LCD panel connections are probably okay and that the problem is likely in the inverter circuitry. Also, if the system remains powered up, take this time to shine a bright light on the LCD and if the video signals are making it to the panel, you should see pixel activity.

You mentioned that you replaced the cable. Was it damaged after the inverter was shorted out? If so, is it an exact replacement? Same goes for the inverter; same FRU on the new one as the old?

I would guess that there might be a problem with the power going to the inverter board. It's possible that there is a component which is damaged on the motherboard and is causing one of the thermal fuses to open up.

#3 Post by **RealBlackStuff** » Thu Jan 25, 2007 8:40 am

I did replace both cable and inverter with the exact same numbers.
With the new LCD-cable inserted and without inverter the same problem remains, spin up for a few seconds, then conk out.
Retry is only possible after removing the power for a few seconds.
I'd still say this points perhaps to a blown capacitor? But which one...

The original cable is burned around the rectangle where the inverter connects into, one of the contacts on the outside of that white 'block' is blackened and looks 'burned through'. The original inverter does not show physical damage, but I have not tried it again for fear of damaging the new LCD cable or something else.

I have not yet taken out the motherboard, to see if there is anything 'burned' there as well, because with an external monitor everything is still working. Is there a circuit diagram anywhere of these mobos?
( mine has an Assembly 2 board with security chip).
Any hints or specifics of which component might have been damaged, and would this be repairable? I am a dab hand with a soldering iron.
Are these thermal fuses repairable?
I appreciate your help.

#4 Post by **rkawakami** » Thu Jan 25, 2007 1:32 pm

Okay, this is what I have so far:

- new cable connected to the motherboard and no inverter installed = no power up
- disconnecting the cable = power up.

That appears to say that there could also be a problem with the LCD panel itself. The two things that I can think of are:

- disconnect the ribbon cable from the back of the LCD, leave the other end connected to the motherboard, remove the inverter and try powering up
- assuming that works, power off, re-install the inverter and power back up again (keep the LCD panel disconnected)

As far as I know, the schematics for any of the Thinkpads are not available outside of IBM/Lenovo. I have tried searching for them before and could not find anything. You may want to extract the motherboard from the system and go over it with a magnifying glass to see if you can see any obviously burned out component. The main problem if you DO find something wrong, is identifying what it is/was and then getting a replacement. I've had some luck in finding replacments for parts that do not have any definite part numbers marked on them (fuses, switches, connectors, etc.). Components that are marked with the manufacturer's part numbers are usually easy to identify and track down.

Soldering parts on the motherboard can be very difficult if you have not had any experience with surface mounted technology. You definitely need a low-wattage, sharp-tipped soldering iron and good eyes. It also would help if you have a digital multimeter for checking some basic things like fuses and/or voltages. Here's what some of the thermal fuses look like:

http://www.schurterinc.com/pdf/usa/c_pfme.pdf

The ones I've seen on the T23 motherboard are about the same green color as the printed circuit board.

Sorry I can't be more specific in what kind of part you should be looking for.

#5 Post by **RealBlackStuff** » Thu Jan 25, 2007 2:03 pm

Thanks Ray, those were excellent suggestions.
With an external monitor attached, it boots up with the new LCD-cable attached, and also with LCD + inverter attached.
It even boots up with LCD-cable, inverter and old LCD-screen attached, displaying of course on the external monitor.
When I then hit Fn-F7 to change between external monitor and LCD screen, it promptly dies, meaning 'only' my LCD-screen is bollixed.

Now my original question applies again: are there any LCD-screens from e.g. the T2x series that are compatible with the T30?
These seem to be more widely available (and cheaper).
I currently have a 14.1" XGA Hitachi TX36D37VC1CAA,
P/N: 11P8292
FRU: 11P8297
150nit.

#6 Post by **rkawakami** » Thu Jan 25, 2007 2:25 pm

That I don't know. Physically, you should be able to mount a 14.1" panel from a T2x into the T30, as long as the mounting screws are located in the same places along the side of the lid.

The only bug in that plan is that there may be differences in the way the signals are routed up the ribbon cable to the back of the LCD panel. I don't know if there is an "industry standard" in the way that the connectors and signals are arranged on the back of LCDs. I couldn't find any references to replacing a T30 screen with one from a T2x system in the archives. Maybe someone else here can supply that information.

thomaslp · #7 Post by **thomaslp** » Wed Jun 11, 2008 3:21 pm

Hi,
I am facing the exact same problem. Did you guys ever find a solution for this issue?
If unplug the LCD cable from the motherboard and then uses an ecternal tft it works fine.

deedoodee · #8 Post by **deedoodee** » Mon Jun 23, 2008 8:13 pm

connect external monitor boot to bios setup check your setting in display set for lcd and external save setting reboot again to bios setup
and see if both diswplay at the same time.
make sure you are set to pci not agp
if boith work you are fine now you can set to lcd only if you like.
i had simular problem getting a new lcd cable inverter and lcd panel to work. this is how i fixed it.

T30 Display and power problem

T30 Display and power problem

try this have you?

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