Laptop Display very dim

[Tobiax]

About a week or two ago, my HP Compaq 8510w display began to flicker slightly. It was very faint and it wasn't flickering on and off, so I ended up just turning it off for the night. There weren't any problems using it the next day, but the following day the display did not turn on (or rather, it was so dim that I did not realize it was on). The display showed up fine on an external monitor, so I assumed that the video card was fine and that it was probably an inverter issue. I bought a cheap "compatible" inverter replacement to just test it out, and when that was plugged in the display worked at its normal brightness with the screen flickering on and off very rapidly (the inverter was also letting out a high pitched noise at first).

After that I immediately removed the inverter and purchased the correct inverter model (452214-001) from HP, but after plugging that one in to the display there was no difference from the original inverter. The screen was very dim and almost dark, but you could still barely see things being displayed.

If the cheap inverter I had bought hadn't displayed the screen at a normal brightness I would've normally just went ahead and replaced the back light, but now I am unsure of what to do next. For now the laptop works fine using an external display, but I would still like to get it fixed so I can use it as a laptop again.

 

[Ironsounds]

Hello... replace original inverter and replace the lamp... Lamps, like the standard household light blub, go Bad.

 

[Tobiax]

Hello... replace original inverter and replace the lamp... Lamps, like the standard household light blub, go Bad.

I did replace the original inverter, but I purchased 2 different inverters. One from HP and one from a 3rd party. When using the 3rd party replacement inverter the screen is bright, it just flickers on and off every so often. When using the new inverter replacement with the correct model from HP, the screen is still very dim.

Like I wrote earlier, I would ordinarily just replace the back light at this point if it weren't for the fact that when using the 3rd party inverter the screen is bright and seems to work fine (other than random flickering and the screeching noise the inverter makes). Since the screen can get bright (just under poor circumstances), should I be looking for other problems or just replacing the back light anyway and hoping it fixes the display with the HP replacement inverter?

 

[Ironsounds]

Hello... Like I said bulbs do go Bad... They are flouresent bulbs... like the ones you see in building all over... Have you seen how they flicker and Dim? They just don't always turn off when they go BAD... It can be full time job, just changing them, in a public building... And there are more than one bulb in most displays... Sounds like with a bulb and your present spare inverters... you can find the right combination together, for your fix... and return one of your inverter for credit?

 

[Tobiax]

I assume that by bulb you mean the CCFL back light. I am well aware that the symptoms indicate that I should just replace the back light, but I guess my question is why is the 3rd party inverter is able to force the back light to illuminate while neither the original or replacement 452214-001 inverters can.

I just want to be sure I have the problem isolated before having to disassemble the display. Thanks for the responses so far.

 

[Ironsounds]

Hello... the flouresent Bulb is High voltage low current... thus energy efficent... But that Dam Blue Color... the only TWO Parts required for the system is the... inverter and bulb. I suspect the 3rd party inverter is putting out a higher voltage and/or current to the bulb, than the OEM spec.