T61 screen repair question

my 14 month old t61 screen has stopped functioning. I can see a faint image, but with no backlight at all. It is 2 months out of warranty and lenovo wants $575.00 to repair. Hardly seems like a good value, so I have decided to attempt self repair, but so far no success. I am quite frustrated and would appreciate any insight.

My t61 is a Type 7662-CTO, 2.5 T9300, 160gb 7200 HD, wxga+ 1440 x 900 Type 42T0427 LG screen. I purchased a new screen that i believe to be the exact replacement LG LP141WP1 (TL) (B8). Additionally I purchased a new inverter Type 14W4178. I was able to take apart the screen bezel and remove from hinge without incident. Close visual examination of the inverter reviled a small dark spot on the circuit board near the hard drive display lamp.

The first thing I did was change the inverter and try booting. Same problem, not light from screen. I then replaced the screen and tried booting again. Same problem, not light. I then ordered another inverted thinking maybe the replacement was somehow defective, but the second replacement does not work either. I am not positive, but when I booted after installing the second inverter card, I think I may have herd a small popping sound.

It now occurs to me that maybe there could be something else at work here. Is there something that could be causing the inverter to fail? The small function lights work fine, so it appears to be receiving power. I am at my wits end with this machine and am seriously considering smashing it into little bits. (only kidding.) But, I am generally pretty good diagnosing and repairing electronics but this one has me stumped. I would be grateful for any help that would allow me to get this laptop functioning again.

 

Hook it to an external screen to see if it is the LCD that's broken. If it works on the external screen the next obvious culprit assuming you've done everything correctly would be the LCD cable.

 

Thanks Zaz. It works fine through a external. The guys over at thinkpad fouum seem to think its the motherboard. I did have a problem with overheating and sudden shutdowns a while back, and now this is all starting to make sense. While I can not be cretin, the little voice in my head is telling me that this screen problem that can not be fixed by replacing the screen may have been caused by the overheating problem. I did open a service ticket a month before the warranty expired regaurding overheating, but Lenovo just gave me a bunch of stuff to try and never took the machine back. I really have the feeling like I have been "Had" by Lenovo.

 

If you can see a faint image but no backlight, I doubt greatly that it's the motherboard.

My first guess would be that the display inverter is the culprit. That inverter supplies power to the backlight. Another possibility is the display flex cable is damaged. That shouldn't be an expensive part to swap out and see if it fixes the system.

 

I am wondering how much these screen costs. My old laptop too has a weak screen showing clear signs of aging. And where might one make purchase of such a replacement component?

 

Thing is the OP already changed the inverter cable twice and didn't worked.
Now I suppose that by changing the whole LCD assembly it includes a new backlight that it may be the culprit of the problem.
IIRC a user at thinkpads forum offers to repair broken backlights, you may want to contact him and ask for his feedback on your particular issue.

 

Thank you for all of the help guys. I think I reached the limit of my ability, and defiantly my patience limit with this machine. 2 screens and 3 inverters will do that i guess. Anyway, at this point I think I am going to just sell the machine broken. Hopefully it will bring a few hundred and I will just get a new laptop. Unfortunately, its not going to be a Lenovo. I did like it, but I just do not like the way they do business. I called today and even though I made a claim before the warranty expired, they stood behind the fact that it was now out of warranty. And when I asked if it even mattered that I started an service ticket prior, the rep hung up on me.

Its always been amazing to me how if you just do a little hand holding treat people with respect, you can keep their business forever. I can accept that the rules are the rules. But hang up because you do not want to answer their question and you get someone like me who will go out of their way to say to everyone I know, I wouldn't do business with that company, they do not treat you with respect.

Goodby Lenove. see ya...

 

Hey Rob,

Can I just ask how you managed to take apart the screen bezel and remove from hinge without incident? I've not been able to get to the screen without taking the bezel off, and cannot get this off without it snapping as it designed to tight..? The partcode I need for replacement, 42X5060 is only about £25.00 but was intregued with the fact you removed without any problems lol and was wondering how...

Also, from what you describle I am having exactly the same problem... I guess you never got to the bottom of the issue? Will keep you posted if I find a solution anyway, although guessing you've parted company with yours now?

Cheers!

Simon

 

GPU or graphics related failures can also manifest in the internal LCD not working, because there is separate subcomponent that controls the internal and external LCD.