IBM Thinkpad T40 LCD goes dim after boot up

[retrobeast]

The screen is fine for a boot 2 seconds then goes very dim. Attached monitor comes up fine.

 

[overclockingrocks]

sounds like a backlight issue to me. I'd check that and also the inverter board as well one or the other may be going bad. I'd suspect the backlight as if the screen is dim but still readable the inverter board is still functioning