Flickering and dead LCD backlight

austinpctech

Junior Member
Jan 7, 2004
5
0
0
I have an IBM T21 laptop that has an LCD backlight problem. Upon bootup, the backlight comes on momentarily, then flickers, then goes dead. I have replaced the inverter with a new one, however it has the same effect. Plugging in a monitor works just fine. I have not yet tried replacing the backlight yet.

Anyone have any ideas?
 

LatexRat

Member
Aug 27, 2000
168
0
0
hey. i have the same problem with my Toshiba 1800. However it works for a while (30 minutes), then craps out.
I figured it might be my inverter, but i havnt bought a replacement yet. I too have hooked up a vga monitor, and it comes up fine. I believe it something to do with the voltages going to the backlight. perhaps too much voltage coming from the motherboard to the inverter? Forgot to add. that i can cycle my outputs (lcd,vga,tv) and it comes back on... Sometimes for a while, but eventually it only flickers on for a second. Also, if i unplug the power. if it was in when the problem starts. the problem usually stops for a while, but then eventually it happends again.

All this leads me to believe the inverter is either getting too much, or too little voltage. Perhaps a resistor would help if voltage is too hight, or a capacitor if its too low?? I'm no electrical engineer, so i can only guess.. I am gonna pop open my laptop and monitor the voltage coming from the inverter, and see if it fluctuates. hopefully i dont mess stuff up more :)

Thanks,
KK
 

titanmiller

Platinum Member
Jan 5, 2003
2,123
2
81
Same thing happened to my HP notebook, I believe I sent it in 3 times for warrenty repair for the backlight but it never stayed fixed for more than a few weeks. Finally they decided to replace it with a new computer (much better than origional) so it worked out in the end.