Thinkpads Forum

Hi,

on my 600 i have the following problem, if i turn it on the display remains black, if i look exactly i can see the display flicker, but it is still black it changes from dark black to a grey black and back...i can't see anything even if i put a lamp on the screen...
BUT, if i press fn+F7 the display turns on and working without any problems, it is very bright and there is no flicker...even if i change the position oft the tft (moving back/front)

what could it be? inverter, any connections?

Any idea?

btw.: what is the exacltly difference beetwen the 600 and a 600e, the cpu socket? mmc1 to mmc2, the graphics, any important difference?

thanks in advance

My guess about the display is the little switch that tells the laptop that the lid is closed. I really don't know how to fix it.

The difference between the 600 and 600E is the 600 uses MMC-1 cpu's and the 600E uses MMC-2 cpu's. MMC-1 go up to 400Mhz PII and MMC-2 go up to 850Mhz PIII with SpeeedStep. They both use the same graphics chip, but I think the 600's uses ISA interface, or something that is really old while the 600E uses PCI or AGP. I am really unsure about that, but the 600E does have better graphics performance on the same graphics chipset.

Stargate199 wrote:My guess about the display is the little switch that tells the laptop that the lid is closed. I really don't know how to fix it.

You are quite correct about the lid switch causing this type of problem. I have simulated a "stuck down" lid switch on a 600E and it operates just like the OP stated; powering up the laptop leaves the screen's backlight off until you cycle through the LCD/external video settings with the Fn+F7 key sequence.

I have found a replacement switch and posted the information here before. I also have a web site at:

http://www.rkawakami.net/ibm_600x/sub_card/

I would suggest "toggling" the switch up and down several times (with the laptop off) to see if it is just stuck or dirty. If that fails to permanently fix the problem, then you have two options:

- replace the entire Sub Card
- replace the lid switch

Thanks!!!

yes it was the lid, just cleaned it and it works...
small problem cause big effect


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