T21 Startup Problem

[russb]

I have an IBM Thinkpad T21 that Im having a bit of bother with. The laptop powers up ok but nothing appears on the screen. The hard drive light flashes a few times then nothing happens but i can hear the drive is still spinning up.

For a start i thought this was a problem with the screen so i hooked it up to a monitor that i knew was working but still nothing. I then reseated the memory and still nothing

Is this a know issue and is there anything i could try to resolve this?

I have tried the hard drive in another machine and it works fine. The only other LED that stays on is the power LED.

Any ideas?

thanks!

[Robbyrobot]

For a start i thought this was a problem with the screen so i hooked it up to a monitor that i knew was working but still nothing.

Do you mean an external monitor attached to the video port? Or did you attach a known working LCD display to the mainboard?

If you get no signal on the LCD display (no dark image due to backlight failure either) and none on an external monitor (make sure to cycle through the Fn-F7 combination several times to make sure), something's probably wrong with the video signal.

[russb]

Sorry about that, I meant to an external LCD Monitor. When the cable is unplugged i get no signal on the external LCD Monitor but when i plug it into the laptop the no signal text disappears but nothing happens when i press FN + F7?

[russb]

Ok, since my last post I have opened the laptop and disconnected and reconnected all of the connections and reseated everything (processor, memory etc) now when i turn it on it works on an external LCD monitor and theres a very very faint image on the screen of the laptop. Is this an issue with the backlight?

[Robbyrobot]

That sounds positive

In that case, you may be lucky and it really is just a backlight problem, not something to do with the mainboard.

The only problem now is how to test for what's defective... you could have a bad inverter, a bad CCFL (backlight lamp) in the LCD panel or a defective LCD cable. The ideal situation would be to have another display (a good one) and switch components until you find the defective one. It would even be sufficient to have a second defective display to switch parts if the same part is not defective in both displays.

If you start buying individual components to test (inverter, cable, panel) and are unlucky, you could end up buying all the parts of a display - which generally costs more than a complete display - before you find the defective one. Of course, you could get lucky and replace the defective part - for example the inverter - on the first try.

If it were me, I'd try to find a display with a cracked screen or one where the seller states that the LCD panel is defective. That would be cheap and you'd definitely be able to locate and probably fix your display, since you'd get a functioning inverter and LCD cable and if replacing those doesn't fix the backlight problem, the defect is probably the CCFL tube itself.

Incidentally, you can get lucky buying "defective" displays... I bought a T22 display described as defective at Ebay last week, and when I hooked it up to my T21, it worked perfectly

[russb]

Thanks for your response. Luckily someone I know has a t23 (i think) and he reckons the screen will fit, I will try it this week and let you know how i get on