Got this weird problem with the backlight of my HP Pavillion zt1150 laptop. I'll be using the computer, sometimes for hours, when suddenly the backlight goes out. If I depress the little spring-loaded switch (the one that tells the system that the lid is closed), then release it, the display comes back.

The problem is that this happens in "clusters". Inevitably, the backlight will go out again in a few seconds, and I have to go through the switch-pressing routine again. This cycle continues anywhere from 5 to 20 times, (driving me nuts!) and then, as suddenly as it started, just stops. Typically, I can then continue using the computer for another hour or two before this beast rears it's ugly head again.

It almost seems like a software problem, but I haven't found any new display drivers on the HP website that I could install. Could it CONCEIVABLY be the inverter? (And if so, could a reasonably tech-savvy guy like me perform the replacement?)

TIA,
Dave

Welcome to SAF!

It could be the inverter board or the backlight tube itself. Those are the most likely causes. It could also be a number of electrical issues.

Hitting the switch cuts and restores power to the screen - which resets the backlight.

Is it still under warranty? If so, I would make them fix it. I would not try this unless you have moderate experience in electronic repair. I am all for learning how to do stuff, but this project could become VERY expensive.

Thanks, efabes!

I like my HP, but it's 3 years old, well out of warranty, and if I end up killing the patient on the operating table, well, que sera, sera. Actually, I'm an EE and have done my share of repairs & upgrades, so I'm not too concerned.

I would like to know one thing, though -- is the inverter in the main body (ie, lower part) of the laptop, or is it in the display section? I took apart the main body, but didn't see anything that looked like the inverter module. I'm hesitant to start disassembling the display module unless I know for sure that that's where I'll find the inverter.

Dave

I am not sure. You are more skilled in this area than I.

I did find THIS site that offers service manuals.

I downloaded one for the Armada. It does have some basic display removal info and a parts list, but I did not see the inverter listed. The site says it has schematics, so that should help if you can find the correct one.

If this does not work, post back. Someone else may know....

This is an old post, and I don't know if it was resolved. On the chance that it was not, I have one thought on it.

For a LONNNNG time, I would turn on my computer and, about half the time, it would turn right back off again....before Windows or anything could load. I posted to a help forum, and checked various things. It was months later that I happened to look directly at the "on" switch when I turned it on one day. I knew instantly what the problem had been all along.

I suspected all kinds of things (CPU, MoBo, etc.), but the culprit turned out the be the on/off switch itself. When I pushed it, it only came partway back out. It would stick just enough to turn the computer right back off after I turned it on. It was a situation where I had to be looking directly at the switch to notice it. A little WD40 (just a VERY SMALL shot) fixed it. Once the switch would release all the way, problem was solved.

Don't know if this could be your problem, but thought I'd mention it. It sure sounds like the switch isn't totally disconnecting every time, then eventually it does.

Anyhow....just a thought.....