10-23-2013 04:55 PM
Hello to one & all
T400 - ONE
I have a problem with two T400 thinkpads. The first T400 was dead when I bought it ( suspected graphics card ) . Well I managed to get this laptop to boot up. The screen was black but I found by chance that if shine a lamp or light on the screen it is working. Now being able to see what I was dooing on the screen faintly. So I updated the bios & that did not fix the problem but I was well happy about finding out this trick. I then added 8Gb kingston ram which works with my other T400 laptops. I installed Win 7 ultimate. The laptop is working fine. No issues just extreamley dark screen almost black "but working" Very strange indeed.
T400 - TWO
Now the second laptop was working fine. But I was swapping the parts with the non working laptop to determine the problem. Now I have two T400 laptops with a dark almost black screen. But over about a month working on them I am making progress. I am determind not to give up on these computers. This is not like fixing or repairing a computer. More like rezerecting a computer. I did not intend to spend so much time on these laptops but I have found a common problem that effects a lot of people. I would love to know why a working laptop when re- assembled gives an almost black screen & still works. Normally I would just buy a new motherboard & bin the defekt one. I was quoted 150 euros from a specialist to fix a graphic problem that does not exsist, Don't get me wrong the engineer was not trying to rip me off. I would have got a new graphic processor in my computer. I normally buy dead thinkpads fix them & sell them. What I need is some command codes to try to make the screen brighter or any other ideas are welcome. Is this planned obsiletion or just a graphic defekt myth. Because after throwing away more supposidly dead motherboards with a graphic defekt than I can count. I am starting to think that if I get the brightness back on my computers I will have sloved a major black screen problem. It is not the graphic processor. I have been playing fifa 14 with a lamp shining on the screen. It played fine, not jumpy ,no colour stripes just very dark.
Thanks & Sorry for the long ramble ***KANARA***
Solved! Go to Solution.
10-23-2013 05:03 PM
HI there, it seems you are suffering from dead screen inverters, maybe you shorted out the second one when swapping parts. Look at the Hardware Maintenance Manual for the T400, find the inverter FRU and order one to test the screens.
I think your problems will be solved. Post back with results, help others solve similar problems.
10-23-2013 05:10 PM
10-23-2013 05:15 PM
07-16-2014 09:35 AM - edited 07-16-2014 09:37 AM
I've got the same problem as above - very dark screen.
I've replaced (just for try from another one) both inverter and the LCD screen. But still the screen is very dark.
What could it be?
As there're both inverter and the LCD ok, what could be the reason?
The laptop Type is:2767-AK4
07-16-2014 10:19 AM - edited 07-16-2014 10:19 AM
Did you also replace the LCD Cable?
07-16-2014 10:20 AM - edited 07-16-2014 12:42 PM
Yes, I've just pluged another complete LCD assembly with no effect. Anybody can help me? Is there also in that kind of LCD with the inverter any fuse on motherboard which could fail? Or may it be something wrong with the motherboard?
I've got no idea how to fix the laptop
07-16-2014 01:06 PM
My understanding is that if a fuse is blown you will see nothing, only pure black!
So if the screen it's dark it can be the inverter, the LCD cable or the panel's backlight itself...
07-16-2014 01:15 PM
When I start the laptop I can see very hardly (in very darkness) the starting page, and after that almoast nothing.
Even after replacing the whole LCD assembly (LCD + inverter + LCD cable), it stays the same.
I'm asking about the fuse in the motherboard, because when I had similar problem with the T400s very dark screen (but the one is the LED panel without the inverter) there's the fuse burned in the motherboard.