"Black Screen" on laptop on which I replaced the screen recently

[britechguy]

The college student for whom I replaced the cracked screen a few weeks back has contacted me again. She's not trying to claim any issue with the screen, cracked or otherwise, with the replacement, but is reporting that the machine is firing up, keyboard illuminating, but that the screen remains black. No sound, no Dell splash, nothing.

I know that the connector for the display was very carefully seated (and has pretty much a death grip in its connectors) at install time so I'm doubting this is the issue, but it could be.

Just checking to see if this rings any "obvious to check" bells other than the connectors for the screen before I have to tear this thing down again.

 

[seashore]

Over the phone:
Ensure no peripherals are plugged in.
Ask her to do a hard power off then power on.
If she can remove the battery, get her to flush power.

In your hands (or over the phone if she's willing):
Reseat the RAM.

Did you tape down the display connector?

 

[Larry Sabo]

Anything on an external monitor?

 

[britechguy]

Gentlemen,

Thanks for your input. I will be receiving the machine itself around 4:30 this afternoon, and will know more then. I appreciate the suggestions, and will report more as I have it.

This was what I call "preliminary research." Very often something rings a big bell for someone else who's "had exactly the same issue" in the past.

I will definitely be trying the external monitor trick again, as that's how I found out that the original replacement screen was defective.

 

[alexsmith2709]

As there is no Dell splash screen that pretty much rules out drivers/software. If an external monitor has the display i would be checking both ends of the display cable, although you have have secured the screen end, its possible, due to the movement when replacing the screen the other end may have become a bit loose.
When you have it check for any flashing lights, like the CAPS LOCK and power light. I believe Dell are one of the manufacturers that have a flashing light combo if there is a BIOS issue.

 

[Porthos]

My vote is for being stuck in sleep due to fast start in Windows. Power cycle the machine without battery.

 

[britechguy]

Well, now that I have the machine in my possession, and have been able to power it up while connected to my TV set, I can confirm it boots up just fine and that there is no issue with the display on the TV set.

The display on the laptop itself definitely has the backlighting come up, it's unmistakable when it fires up, but absolutely nothing displays on the screen at all. This strikes me as odd if the video cable were loose, but it's certainly not impossible.

Any other suggestions before I tear it down again to check the video cable connection? If it did somehow come loose I can't, in good conscience, charge for this service, but if that's not it I don't know whether to suspect a *second* screen that's died in very short order or not. The machine shows no signs of abuse, it's not even scuffed on its case.

 

[Larry Sabo]

Do you have a known-good, compatible test screen you can swap in (after disconnecting the built-in battery and AC power)? If no change and the connector is well seated at both ends, sounds like a motherboard (GPU) problem, possibly bad BGA solder joints.

 

[britechguy]

No, I don't have any screen I can swap in. I only buy parts of any sort on an "as needed" basis, and I very, very seldom need replacement screens.

Thanks for the tip regarding the mobo. If reseating the cable does not work, I am going ot suggest that she return the unit to Dell for servicing.

 

[mikeroq]

Do you have a known-good, compatible test screen you can swap in (after disconnecting the built-in battery and AC power)? If no change and the connector is well seated at both ends, sounds like a motherboard (GPU) problem, possibly bad BGA solder joints.

I tried to keep as much stuff available for testing as I could. Boss wasn't going to buy anything for that. More than once I took the screen out of my Thinkpad to test on another laptop or plug a screen in to test.

Could simply be just be a failure in the motherboard. Nothing related to the screen or your repair. Sometimes the stars align.

 

[Porthos]

If reseating the cable does not work, I am going ot suggest that she return the unit to Dell for servicing.

Is/was it still under warranty?

 

[britechguy]

Yes, it is/was. I warned her when she asked me to replace the screen that it could possibly void her manufacturer's warranty, though I have no idea whether it would/did necessarily do so.

The computer is not even a year old. It was "born" last September.

 

[Porthos]

Yes, it is/was. I warned her when she asked me to replace the screen that it could possibly void her manufacturer's warranty, though I have no idea whether it would/did necessarily do so.

The computer is not even a year old. It was "born" last September.

Was this that "taped" in screen repair little ways back?

 

[britechguy]

Was this that "taped" in screen repair little ways back?

Yep.

 

[Porthos]

Yep.

The screen should be under warranty.

 

[britechguy]

The screen should be under warranty.

I do know that, but I will be incredibly, incredibly PO-ed if a *second* one has "gone dead" this quickly. I've done screen replacements over the years and never had this much trouble. This isn't even a touch screen.

I am truly hoping that this is a loose cable, but no matter what I have a teardown to do, which is really irritating under the circumstances. I have to check the cable connection first.

Last night, when I was using an HDMI cable I was getting "intermittent quick blackouts" but that could be that particular cable, so I intend to test again using another I know to be absolutely rock solid before I start taking the machine apart. It seemed to occur when I had to move the machine slightly, so I suspect a wire going bad in the cable, which is an old one and ribbon style.

 

[nlinecomputers]

Rereading your other topic I say you have a bad motherboard. The original unit was dropped or had an impact. It’s possible that the motherboard is cracked.

 

[britechguy]

No, the unit was not dropped, ever. It was a "lid closure" screen crack, and with these damned micro-thin lids that are barely more than a plastic sheath around the screen itself, I expect to keep seeing more of this.

 

[nlinecomputers]

No, the unit was not dropped, ever. It was a "lid closure" screen crack, and with these damned micro-thin lids that are barely more than a plastic sheath around the screen itself, I expect to keep seeing more of this.

Well clients lie, so there is no guarantee of that. And it’s just as likely to be an impact damage. Hard closing the lid, rough handling in a backpack. And often not even realizing it. it real easy to have it in a backpack slung over your shoulder and catch a doorframe. You think it was a minor bump….

 

[britechguy]

Actually, I think it was a screen flex. The design on these ultra thin laptops, even the really expensive ones (and this is) is just appalling for the screens. If you don't close either from the center or both ends, a flex crack is virtually guaranteed.

Anyway, I'm not here to argue this with you. I have the skills to recognize a computer that's even early in the process of living in "the school of hard knocks." This does not appear to be one of those. It's pristine in virtually every respect.