T400 LCD screen is very dim, but icon lights for HDD, etc. are working

[nk9781]

Hi - I'm wondering if anyone knows what the issue with my T-400 would be if the LCD screen is very dim.  Details include:

- When I boot up, there's a faint outline of what is going on, but barely noticeable since the whole screen is very, very dim

- Video card is working okay, because I can operate the laptop when I plug in an external monitor

- The icon lights for HDD, power, battery, etc. are still working

Thanks so much for the help.

[richk]

There 3 several possibilities. The backlight could have burned out. There is a fuse on the motherboard. If you have a CCHL backlight, there is also an inverter that could have died.

[nk9781]

Thanks very much for the response.  Assuming it is not the 2nd issue (i.e., motherboard fuse), can it be fixed by just buying and replacing the LCD?

[richk]

First a question: Is it a CCFL backlight or LED? If it is a CCFL, it could be just the inverter, which is a lot cheaper than the panel. If the CCFL bulb goes out, usually (but not always) there is a red tint to the screen for a while first. The LED backlights are less likely to blow and there is no inverter. (The LED backlight is DC and the inverter convers the DC to AC to drive the CCFL bulb) Do you know which kind of backlight you have? If you don't know, send me your full model and serial in a pm and I'll look it up. Don't post it in the open forum. Also, what were you doing when it went out? Were you doing anything except normal work, like taking something apart or hooking something up?

[mccready]

Hi,

I have the same exact problem with my T410 - the symptom happened once, then worked normally after a suspend/resume cycle, but now it is back and doing a suspend/resume, restart or a battery removal while unplugged will not  fix it.

Just wondering a solution for the above was found, as there seems to be a fair number of other posts about the same problem sent back unrepaired, and I would love to give some direction when my laptop gets sent out.

Thanks,

--Gary

[nk9781]

Sorry, I couldn't figure it out. 

[mccready]

So I guess yours is still broken?

My in-house tech says they'll need to replace the motherboard, which of course will take at least 6 days once sent off...hopefully that will do the trick for me...