I recently had an unexpected part 3 to this tale the other day, when the display went. Again. But this time, different symptoms. This time, the backlight went. Oh sh*t, replacing LCD panels isn’t exactly cheap, and since the backlight diffusers and CCFL’s are fused to the back of the LCD panel itself, there was no way of replacing the individual unit.
But wait, it’s a CCFL. That means it has a HV inverter. Stripping the LCD casing down to reveal the inverter, a distinct burning smell wafts out of the casing. Though the board doesn’t look burnt out, sliding away the protective plastic around the HV coils and a close sniff, a slight burnt-out-electronics smell was present.
A quick turn to eBay later and I found a replacement inverter board (Part #: 19.21072.081 – not a Compaq/HP unique part. This board is used in many different brands of laptop screens) for £18.50. I could have had a used one (probably from a spares/repair unit), but I’d rather have a new one. Swapped it out, put it all back together, LCD backlight now back in action.
For those wanting to attempt this themselves, here’s a basic run-down of what you need to strip down to get to the screen.
- (And most obvious), remove all power sources. You’ll need to have the battery out anyway.
- Flip the laptop over, so that the back of the laptop is facing you, but upside down.
- Remove the 2 screws in the bottom left and right hand corners.
- Where the battery sits, there are 7 screws you need to remove. 3 hold the keyboard in place, the other 4 hold the plastic keyboard surround in place.
- Remove the panel covering the wireless card, and disconnect the 2 antenna cables. You’ll see why later.
- Flip the laptop back over, open the screen, and gently pry the plastic surround away from the rest of the chassis. If you hold the laptop left and right, and push firmly backward on the plastic surround, it should start to ease away. Don’t push it too hard, or move it too much when it’s loose. There’s a short ribbon cable connecting the power/wireless buttons/LED’s to the main board. We want to remove that, but gently.
- Fiddle under the keyboard and slip the ribbon cable out of it’s connector. Put to one side.
- Now you’ll see what I mean in #5 about the short cable. You can gently pull this out, but there’s a small piece of plastic that sits above the cable in the connector slot that comes loose. Make sure you have eyes on this. If it pops off and you lose it, your laptop might as well be dead, since without a power button…!
- You need to remove some cabling now. You’ll see 1 thin cable coming in on the right hand side, and goes inside the unit. Out of the same area, another similar sized cable goes to the right. These are the antennas you disconnected earlier. Pull them out. On the left hand side, there’s a large cable with the connector facing to the left. Disconnect this. Gently. It’s double-row pins, so they’re extremely fragile. Lastly, there’s a cable going to where the caps-lock LED is, which goes to a connector roughly where the Alt button would be. Another cable coming from this connector goes towards the screen. You’ll need to remove the LED from it’s slot (a gentle-sharp tug should do the trick), and disconnect the connector it goes to from the mainboard.
- You should now be able to see (and get to) the screen’s hinges. There are 2 screws each side holding the hinges down. Remove all 4 of them. Pull up on the left-hand-side first. This has a metal stabilising pin which holds it all in place. Then wiggle the screen gently back and forth, tugging upwards until the right-hand-side bracket is free. Put the rest of the laptop to one side.
- At the bottom of the screen are 2 screw covers. Remove them both, and the screws that they cover.
- Using a thin flat-blade screwdriver, prise the 2 pieces of the LCD’s housing apart. It clips itself together all the way around the screen. Do this until it’s free. Put it to one side.
- Looking at the base of the screen, you’ll see a small, long, thin circuit board. 5-pin cable coming out of the left, 2 pin cable coming out of the right. You’ll have to do a bit of fiddling here as I can’t remember exactly how it came out, but it clips into place in the LCD’s housing. Once free, disconnect both sets of cables.
- Replace the now removed inverter board with the new one. Both sets of cables only go in one way, so you don’t have to worry about that. Clip the board back into place, and re-fit the LCD’s housing. Clip it all the way around, replace the 2 screws at the bottom, and re-fit the screw covers.
- This bit, I reckon, is the trickiest. Positioning the screen at the back of the laptop (where it should be), fit the right-hand-side hinge first. It’s a little tricky to get it in the right place, but it’ll “feel right” when it’s in place. Once it’s in, do the left hinge. This one’s easier as it has that guide/support pin. Once in place, replace the 4 screws that hold the hinges down.
- Time to re-fit the cables. Do the caps-lock LED cable first. Position the cable under the guide tags on the chassis, push the LED back into it’s slot, and re-connect the connector into it’s slot. It’s around where the Alt key would sit.
- Put the large display connector in next. Line this up, then carefully push it in. You might want to use a small flat-bladed screw driver to push it gently into place. Check it’s firmly in place before continuing.
- Re-route the wireless antenna cables, and push the remainder of the cable back into the hold they came from. This area is around just above where the backspace key would be. Push the cables into their guide/support tabs and feed the rest through.
- Position the keyboard surround into place. Carefully slide the tiny ribbon cable back into the connector on the board that it lines up with. This is tricky. Be careful of that black plastic support on top of the connector. This provides the “push” required to make the contacts on the ribbon firmly connect with the pins in the connector itself. Push the plastic piece into place and verify that the ribbon is firmly in place before continuing.
- Do the same with the keyboard’s ribbon cable. Place the keyboard inside the plastic surround, and re-assemble. Holding everything in place, close the lid and flip the laptop over.
- Replace the screws inside of the battery housing first. You might need to put the laptop on it’s side with the lid half open so you can apply some pressure on the keyboard/surround so that the screws meet the holes they mate with. Finally, replace the 2 long screws in the 2 top corners.
- Verify everything is in tact (and that you have no screws left over!) then put the battery and power back in, then power it up. If you’ve done everything right, you *should* have fixed the problem.
Of course, I accept no responsibility if you destroy your laptop if you decide to follow these instructions. This is basically a summary of what I did to fix mine. Your mileage may vary. However, if you’re having issues, contact me and I’ll see if I can offer up any assistance.
I’ve taken it upon myself now to see how long I can keep this thing going by replacing parts that fail. It’s about 2 and a half years old now, so it’s bordering on expected life. I’m going to try and get 6 years out of it. We’ll see 🙂