T40 & T42 Having Same Problem, Won't Boot

[msmrinc]

Hello All,

I'm having the exact same problem with two Thinkpads, a T40 and a T42. Neither will
boot up after hitting the power button. Once hitting the power button, the "Power On"
indicator light lights up, and you can hear the cpu fan start up. But nothing, no video
whatsoever, and the harddrive light never hits.

I've tried the "pull the battery, remove a/c power and hold the power switch on for 30
seconds" thing, but that doesn't make any difference. Oddly, I got the T42 to come
up once, and it booted all the way into Windows XP Pro. I had to attempt power on
with that T42 about 50 times before it came up. Really weird.

Any ideas??

[Danny Manabat]

Could be toast ...

http://forum.thinkpads.com/viewtopic.php?f=2&t=83671

[poshgeordie]

Welcome to the forums and sorry to hear of the problems you're having.

If you remove the RAM do you get any beeps?

I'd say you've got the same unsoldered GPU or Southbridge chip problem on both of them.
Remove the keyboard, palmrest and wi fi card at the front centre of the board (under the Tackpad).
Whilst starting up, first press down on the GPU (has ATI on it). Do you get a display? If so you have an unsoldered GPU.
Try the same whilst pressing down on the Southbridge - it's the big square chip with Intel on it under the wi fi card. If the laptop works then it's an unsoldered SB chip.

All isn't lost here because myself and RealBlackStuff (who lives in US) are setting up a board swap out depot for US based Thinkpad Forum Members, and we may have suitable replacement boards for you either straight away or in the near future. PM RBS if this is of interest and read this post and the next few following too.

[twillis449]

I just had similar problems with a T42. I went through the exercises suggested in previous posts but it turned out that the actual culprit was a dying hard drive. Installation of a new drive got things up and running again (after an OS install as well of course).

[Amika]

my t43 is having the exact same problem, switch on only the power light up but sometimes it work without any problem, but when it failed to bootup, i would have to take out both ram reseat it back and it will work sometimes, but recently i found out that if i put a bit pressure one the keyboard connection to the mobo it will bootup... weird...

[poshgeordie]

@Amika - that's classic southbridge solder ball joints which are failing.

[Amika]

@poshgeordie... thanks for the quick reply... which means my t43's days are numbered... since i'm not in USA or UK it would be hard to get a reballing service here...

[poshgeordie]

I've just re-read your first post and maybe I was too hasty.

To confirm the symptom, remove the keyboard, palmrest and wi fi card to get to the SB chip under the wi fi card - big square chip with Intel on it.

Plug the kbrd back in, power up, and try pressing directly on the SB chip to see if that makes it work. Releasing pressure may then cause it to stop again.

Unfortunately it's becoming a very common problem with T43's - rather than the GPU.

[Amika]

nope.. i only put a bit of pressure on the keyboard connector on the mobo.. which is kinda weird... i did try putting a bit of pressure on the SB and GPU before but it wont boot up but only if i put a bit of pressure on and around the keyboard connector that it will boot up...

[poshgeordie]

I do remember having this on a couple of boards and traced it to an area around the underside of the board near the fan. We never managed to fix them unfortunately.

What I did was to completely strip the board (except CPU, Fan, 1 RAM module) and made a board holder which holds the board vertically. This gives access to both sides of the board to press most of the components (you may want to leave off the fan but don't run the board for more than a few seconds without it).

Bottom line - looks like a new board.

[Binh]

My T41 has the same symptom, and it was the fault of the VCC1R2M 1.2v power supply chip (Max1845 IC, U29). I replace it twice, each time the laptop works fine for 1-2 week and then has this failure again. Now I am tired to replace it for the third time

[lukee]

Perhaps some component causing over-voltage on the Max1845 IC, U29 chip? Did you measure it?

[Binh]

Perhaps some component causing over-voltage on the Max1845 IC, U29 chip? Did you measure it?

The supply voltage (VINT16) is normal. I will PM you the voltage table of all its pins afternoon when I get back home.
Strange think is that when it gets failure, if I remove the battery for 2-3 days then it works again from battery (but not AC adapter), but only for 3-4 hours, and then I have to remove the battery for another 2-3 days
I am thinking that I got a bad patch of Max1845

[lukee]

I experienced similar behavior on DELL Latitude C840. After pushing the power button it worked fine about 2 - 5 seconds (able to see POST etc.) and then it automatically powered off. Used Google I investigated, that the one transistor on bottom side of planar may cause this error so I cut the transistor off, three contacts on planar remained, I shorted two of them by 4k resistor and lapopt went fine then. Could it be a similar problem to yours?