T43p screen replacement problem?

[mikiki]

I have T43p with 14" SXGA Samsung 1400x1050 screen (FRU 92P6760).

Since my LCD backlight lamp was dead (as diagnosed by IBM authorized technicans) and buying new screen was not an otpion as it costs too much (about $500), I replaced my old LCD screen with 14" XGA 1024x768 (manufacturer - LG) from T42 notebook (screen FRU 92P6726). Both screens listed here: http://www-307.ibm.com/pc/support/site. ... 58431.html

I did replace ONLY old lcd panel with new one, all cables, screen box, and other things have not been remmoved, all are left from previous screen.


PROBLEM:
After I turn on notebook it works 3-5 seconds (it works until LCD screen should turn on), and then it shuts down
automatically. I can NOT turn on notebook again before I remove baterry and put it back again.

Mystery is I also tried to return original SXGA screen with broken lamp to my notebook, but same thing happens again - it shuts down automatically after 3-5 seconds. Before I replaced original broken SXGA screen, I could still turn notebook on,
and no matter picture was pitch black on notebook, I could still get picture on my TV (connected via S-video cable to notebook).

What went wrong, any ideas? Is something fried or what?



p.s.
I was very satisfied with notebook (while it worked), however just a few days before my warranty expired (warranty 3 yrs) first my cpu fan died and since I didnt have time to sent it to IBM technicians immediatelly, instead few days passed and warranty expired, then in few months later (currenty) now lcd screen is dead. It looks like all notebooks are programmed to die after warranty expires, so i am a little bit angry this didnt happen few months earlier, it is not the first time some part dies just after warranty expires.

[poshgeordie]

Hi and welcome to the forums.

The SXGA and XGA screens use different LCD cables and this will be causing the problem. I don't have the different part numbers but someone else will (or you could do a search).

Does the laptop start up OK if there's no screen cable connected, and can you also say if you can get a picture on an external screen?

Other suggestions - this same problem happens if the CPU is not properly fitted in the CPU holder. Is the screw turned to hold it in place?

Also check the RAM is fitted properly. Also remove the HDD, CD, wi fi and modem /BT cards.

[wild_bill]

why not just find a good SXGA+ in the marketplace here and install that? - they are cheap here and also on the 'bay

here is one that one of the guys here has advertised for only $50!!

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0696233770

[mikiki]

Hi and welcome to the forums.

The SXGA and XGA screens use different LCD cables and this will be causing the problem. I don't have the different part numbers but someone else will (or you could do a search).

Does the laptop start up OK if there's no screen cable connected, and can you also say if you can get a picture on an external screen?

Other suggestions - this same problem happens if the CPU is not properly fitted in the CPU holder. Is the screw turned to hold it in place?

Also check the RAM is fitted properly. Also remove the HDD, CD, wi fi and modem /BT cards.

Hi,

regarding different cables - No matter SXGA and XGA have different cables as you say,
that still doesnt explain why laptop shuts down even when I return original SXGA screen in it?
Now it shuts down with both original SXGA screen and with XGA screen from T42. Before I replaced original SXGA screen with XGA screen notebook would turn on normally.

Laptop starts and shuts down after 3-5 seconds even if I remove/disconnect LCD cable from LCD screen.

Regarding RAM, CPU, HDD, CD wifi and modem/BT cards you mentioned:
I did not touch those parts or motherboard or even saw them, I only replaced old screen with new one as per this tutorial:
http://www.insidemylaptop.com/remove-re ... 3p-laptop/

Is it possible something happened to parts you mentioned during above mentioned screen replacement?

why not just find a good SXGA+ in the marketplace here and install that? - they are cheap here and also on the 'bay here is one that one of the guys here has advertised for only $50!!
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0696233770

i was thinking about it, however i am not sure if that is still an option since I do not know if maybe notebook motherboard is fried or maybe I caused some other damage to notebook with XGA screen i tried to install.

[poshgeordie]

To state the obvious, something has happened to the motherboard for it to turn off after a few seconds.

I think I've read somewhere that if you use the wrong lcd cable with the wrong LCD, then the motherboard may be damaged.

If you have a test meter, it may be worth checking the fuses are all OK - download the doc in my sig and then download the T4x fuses doc from there. I don't think it will cure the problem but may help a little.

BUT also you do need to check that the CPU is properly fitted as I said earlier since if it's not secured properly the laptop will turn off after a few seconds as well.

[mikiki]

To state the obvious, something has happened to the motherboard for it to turn off after a few seconds.

I think I've read somewhere that if you use the wrong lcd cable with the wrong LCD, then the motherboard may be damaged.

If you have a test meter, it may be worth checking the fuses are all OK - download the doc in my sig and then download the T4x fuses doc from there. I don't think it will cure the problem but may help a little.

BUT also you do need to check that the CPU is properly fitted as I said earlier since if it's not secured properly the laptop will turn off after a few seconds as well.

I dont have test meter.
How can i be sure if CPU is properly fitted or not, i looked it and dont see anything strange, however I am not experienced with this stuff.

Any other ideas? I hope motherboard is not dead, as it would mean laptop is unrepairable and dead forever as repair is too expensive.