r61 - problem with backlight

[radim]

Hi to all!
I`m a happy ThinkPad R61 owner (purchased in spring 2008). Unfortunately I did run into an issue with screen backlight couple of weeks ago.

Problem Description:
When hdd LED on the inverter lights up, screen backlight turns off. It produces a nasty flickering effect of the screen. It does not happen only in Windows but also during boot. It basically happens whenever system access the internal hard drive. If system access data on the external hard drive, screen is fine without flickering.

What I tried to do:
1. Connected external screen (external screen works perfectly with no flickering, laptop screen flickers as before)
2. Disassembled laptop and reseated all the connectors in LCD assembly (did not help)
3. Replaced the inverter (did not help)
4. Temporarily removed lid switch on the keyboard bezel (did not help)
5. Removed internal hdd and installed OS on the external USB hdd (this works perfectly, with no flickering of the screen what so ever, but it is not the solution, obviously)

I`m convinced at this point that LCD assembly works perfectly. I`m afraid it is the SATA controller on the mobo which causes this problem, or, possibly, any fuse?? Is there a "fuse overview" of R61 (such as this one for T4x?)

My laptop is ThinkPad R61, type 8918 - DFG (Core2 Duo T8100, 4GB RAM, nVidia Quadro NVS, 15.4" 1680x1050, Win 7 Pro)

This is the first problem I`ve had since the purchase, I would love to get it work again...
I`ll appreciate any type of advice, thank you for your time and have a nice day!

[Neil]

Hi there radim...welcome to the forum!

This is a new one for me. I've never seen or heard of a problem exactly like it. But, looks like you have done an excellent job of trouble shooting already, and I would agree with you that it's a motherboard problem.

I doubt it's a fuse issue, though, because fuses either pass current, or they don't. A blown fuse can make the screen go black, but it won't cause flickering.

Likely, someone else will weigh in that can help you isolate the issue. My only advise would be, start shopping for a replacement motherboard. But, maybe it won't come to that.

[radim]

Thanks for the super-fast reply, Neil!

Replacing the motherboard, that`s quite an expensive affair... Yet, if it comes to that, is it possible to replace my R61 board with T61p one? Those 2 laptops are physically nearly identical... and I like its Quadro FX570M graphics card (since I use architectural and 3D modelling softwares a lot.)

Thanks again

[radim]

Can anyone tell me please, if placing t61 motherboard into r61 chassis is physically doable?

Thank you and enjoy the weekend!

[radim]

Hi, I just want to let you know that the flickering is gone! After returning back from Haiti to Europe, the screen behaves normally. That`s something really weird... It might be my lappy was a victim of voodoo?