Dead Laptop Mystery - for fun only!

I was recently given a laptop to fix that presented bit of a mystery. I eventually got to the bottom of it, but was surprised by the result. So for fun, I'm going to let you guys experience it too! You can ask me questions and what tests to do, though I'm afraid I can only give you the answers to things I did do as the laptop is no longer in my possession. I did try many things though, so I can probably answer most of your questions.

I want to stress, this thread is for FUN only - you won't be helping anyone fix their problems by wasting your time here!

History
The laptop is an ACER 5532, a year or two old, no problems until recently. The owner said that he went to bed one night with the laptop working fine, then woke up the next day to find it was pretty much dead. He didn't mention until later, but it's actually his 14yr old son's laptop.

First Inspection
When connected to the a/c adapter the corresponding LED correctly illuminated to show it was connected to the wall. On removing the a/c adapter the laptop showed no signs of life. With both reconnected, I hit the power button to see what would happen. The power button LED lit up, and the screen went from pitch black (off) to the slightly illuminated black (as if the back light came on) and then immediately back to pitch black within maybe a tenth of a second. Around the same time the CPU fan kicked on full blast, then cut off after a second or two. Nothing changed further over the next 30 seconds to a minute, and ultimately the laptop turned itself off. Without the a/c adapter, the laptop wouldn't turn on at all with the battery alone.

I repeated the same process a few times, and each time the same thing occurred in the same pattern. I also tried outputting the video to a (working) monitor via VGA, but still no picture (or back light flash), and the keyboard controls to cycle outputs had no effect. I put in a UBCD boot CD, restarted the laptop once more, and I felt the CD spin to full speed, but ultimately slowed down after a few seconds and the laptop shut down after 30-60 seconds as before.

 

What I would probably do: (altho I don't have the laptop in front of me so hard to say)
1. any signs of damage? (from drops?)
2. correct AC adaptor?
3. check that RAM and HDD are installed correctly
4. attempt power-on without battery installed
5. leave to charge batter overnight (my old powerbook won't boot unless the batter has some charge and is plugged in.. so i tend to try it if its a power issue of some sort)
... I'll leave it there for now and see what your response is (although i'm assuming that none of these will work)...
*EQL*

 

All good suggestions!

1. any signs of damage? (from drops?)
After inspecting the laptop all over from the outside I determined there were no cracks or obvious impacts. I did notice a sticky drink-like residue on the top right part of the keyboard, which seemed like a small spill. Significantly, I also heard a rattle coming from around the fan, which sounded like a small loose part.

2. correct AC adaptor?
Yes. Correct a/c adapter and battery.

3. check that RAM and HDD are installed correctly
Removed and reseated the SATA Toshiba HDD, and the 2GB and 1GB PC2 5300 RAM modules. I also inspected the RAM when I removed them for signs of a spill or short, but both looked fine.

4. attempt power-on without battery installed
Powering on with a/c adapter connected acted exactly the same whether or not the battery was attached.

5. leave to charge batter overnight (my old powerbook won't boot unless the batter has some charge and is plugged in.. so i tend to try it if its a power issue of some sort)
I didn't try charging the battery overnight, but it had been connected to the wall with the battery in for a few hours and still wouldn't even try to spin the fans when I would try to power up from just the battery, so I assumed the battery or part of the motherboard was just dead.

 

ok, now you said something about the screen showing nothing?? starting to sound a bit like a power issue, graphics card issue, or motherboard issue...
I would carefully check all parts of the ac adaptor, DC-in jack, and anything else i could see for bent pins, etc. If nothing, i would talk to my friend and make sure the warranty had expired, as if i need to open the case it will void any further warranty...
if available, i might switch out the hdd and ram just for kicks to see if anything happens... unlikely but worth a shot while my friend is double checking that the warranty is no longer good .
Also, i would plug the HDD into my desktop and see if it shows... try to recover any data before i mess around too much...
Assuming there is no more warranty and i'm given permission to do watever i want.. hee hee hee...
-prob do a quick google search to confirm no one else has expeirenced a similar problem...
-open up the case, do a quick look for damage, spills. If none obvious, go through and make sure all the connections are attached properly (this has solved the issue for quite a few of my friends laptops)
*EQL*

 

Yes monitor showed nothing, but remember it did flash to the power-lit black screen for a moment, so something is reaching the lcd screen, even if it's just for a microsecond.

I didn't check the DC/AC pins and connectors, but assume they are all fine for now.

The owner told me that the laptop is under warranty but after a long battle with ACER he's given up having them issue an RMA and wanted me to go ahead and do whatever is necessary.

I connected the HDD via a usb multi-connector and it found errors in the extended test and short test using DATA Lifeguard by Western Digital. However after removing it, plugging it back in and repeating the test, it didn't show errors and I started to think the original fail was wrong. I also had no issues exploring the hard drive via USB. As the same problem persisted without the hard drive in the laptop, it was definitely ruled it out as a cause.

 

and thats why i refuse (and tell everyone i know not to) buy an ACER...
*EQL*

 

lets see...
try a reset of the CMOS (remove, wait, and reinsert the battery)?
*EQL*

 

I was interested in resetting the CMOS myself, but also really wanted to investigate that loose part and spill! So I decided to take the whole laptop apart.

I removed the LCD hinge covers, then the LED cover strip (that runs between the keyboard and LCD), removed the keyboard, took off the LCD screen and the top half of the laptop case. Each part seemed to be correctly connected to the next. The spill seemed localized to just the keyboard, with a tiny amount making its way underneath, but far away from any circuitry or components. I took a multimeter to the problem and determined that not only was the motherboard providing power to the battery, and the LCD screen was supplied power during that initial flash but nothing afterward.

The rattle was deeper still, so I unscrewed the mainboard from the bottom half of the laptop case and discovered a piece of black plastic with 4 metal legs coming from it. I recognized it right away as being the inside of a USB port. I took another look at the USB ports and did indeed now see that the inside of one of them had been pushed inwards and broken off.

Unfortunately USB ports aren't essential from a computer to start, so a broken USB port couldn't be the direct cause. I checked to see if any of the broken legs of the rest of the USB port were creating a short, and determined that none were.

 

at this point i would probably put it back together enough to see if it starts up, maybe (although unlikely) the loose peice was causing a short.

 

I reconnected everything (without bothering to reassemble the case halves), and same problem as always . At this point I basically decided the part had been flopping around shorting things out and that by now the board was fried.

 

hmm.. at this point i would probably say its time to pay someone to do it (or, depending on how old the computer is, get a new one and i'll transfer your data over for you).
I'm interested in what the problem did turn out to be.. wonder if it might help me fix a laptop have ive had sitting around for a few months which ive decided to be KIA
It's hard for me to admit defeat, but from the sounds of it; can't see anything wrong, can't find anything wrong, and the parts that I can test are working, so its gotta be something that I wouldn't be able to fix myself anyway..
*EQL*

 

Eh... first thing I'd do is replace the $3 CMOS battery.

That PROBABLY wouldn't fix it, though... just a first step. Then, I'd completely disassemble it, since it obviously survived a drop (I had a laptop that had similar issues from a drop), and see what that inwards pushed USB port pushed with it. Likely a connection of sorts, or tripped a jumper or something.

I'd also double check ALL connections (keyboard, touchpad, drives, screen, etc.) since some laptops have autocheck mechanisms that won't let it start with something unplugged/not properly connected.

Am I getting anywhere?

 

We all want to be Major Geeks when we grow up!

 

Well I am that guy unfortunately!

I didn't have a replacement for it, but I did test it and it was outputting charge.

All the connections were double checked and I'd taken a careful eye all over the board for signs of melted circuit board or any signs of spill or shorting damage, but couldn't find anything.

By this point I was about out of ideas too, and had researched the price of a replacement motherboard ($160 on ebay!). Next I went about stripping the $$$ reusable parts so I could see if the RAM/HDD/etc was working, to offer the owner the alternative of selling it all for parts to try to recoup some value. It was in doing this I absolutely stumbled on the problem...

Last chance for guesses!

 

My next step would be replacing the RAM with known working/tested RAM.

 

lucily im not that girl.. all my repairs are done for free (although i often recieve a thank you card with a tim horton's gift certificate in exchange

thats about the same process i would follow too. Generally, my experience is that, unless its a very recent laptop, the cost of a new mobo is not worth it compared to buying a new (or refurb) computer with better specs (or specs that can be improved by reusing RAM and HDD).

hmmm... makes me think that its going to be something really random yet obvious.. a peice of food in a socket, or a cracked connection between the DVD drive and the laptop, or something like that... maybe even a dead processor...

*EQL*

 

I'd watch what you say.. some people will get VERY offended if you refuse to believe they haven't dropped it. I've seen a laptop where the DC-in was completely destroyed and disfigured. I wouldn't have believed it was never dropped if it wasn't my roommates computer who i can verify NEVER has even removed if from the house... i think it was just a faulty dc-in jack, since she had been having random power issues since she got it. so i ordered the piece online, soldered it in myself, and good as new.
*EQL*

 

i thought i had mentioned this too, but yes, i always also check the ram for errors on another computer.. but i think it was already declared 'not the issue'
*EQL*

 

I'd watch who I give free advice to... I didn't solicit any advice about what I say.

Not that it matters, but I wouldn't accuse anyone of dropping it, and the owner may have been unaware of the drop (it could've been dropped by someone else). What happened to the laptop has nothing to do with blame, it has to do with fixing it.

 

It wasn't.

Assumptions are a dangerous replacement for thoroughness.

 

i didn't? oh.. ok.. must have deleted it when re-wording my post. Good catch then.
*EQL*

 

94dgrif..
i'm ready to hear the result when anyone else playing is ready.. I'm quite anxious to hear what the problem was!!
*EQL*

 

By doing this you might have stumbled across the same solution as I did, so I'll go ahead and finish the story.

I put one of the memory modules from the Acer into a working laptop, and ran memtest. After 5 or so passes that module presented no errors, so I removed it to test the other. I didn't have a good place to keep the good module so I put it back in the Acer. I turned the laptop on and wham... it started showing the BIOS bootup screens! It booted to Windows, and it loaded up just fine. A little bewildered I put the second memory module in (which by now had also passed memtest) and was faced with a black screen again. After trying every combination I discovered.....

...one of the memory slots wasn't working! Putting either module in the other slot worked fine, but anything in the bad slot gave me the same black screen.

My question at this point was: Why a black screen rather than crashes or errors in the BIOS boot up, as you might expect?

Well this is where I had my duh/eureka moment! Being a standard laptop, it doesn't have a graphics card so instead it uses shared memory (borrows a portion from the RAM). Nothing got displayed as a memory slot was faulty, and as the graphics chip borrows memory from the first memory slot. Obviously no text/BIOS info/etc can be displayed on the screen before the problem occurs because the data heading to the LCD is corrupt/missing.

So yes, replacing the motherboard would have fixed the problem too, but the cheapest solution to this problem was just to live with using one memory slot!

 

Yeah... usually with a "dead" laptop, those are my steps... CMOS battery, connections, RAM (and RAM slots). Sounds like a fun one, to be sure!

EDIT: It seems more computers nowadays are having dead memory slot problems... which is sad, because motherboards are one of the higher priced and more of a pain to replace than anything else.

 

Yes EQL did mention switching the RAM out, as of course mcsmc did too. If I was mean I would have posts the successful memtest results and kept hush from there, but I felt I'd kept you guys guessing long enough.

I agree it's dangerous to accuse the owner of causing the damage, but I find if you're 100% honest there's never any ill-feeling. So in this situation I'll say that the damage could be from pushing a USB device in upside-down too hard (it is a flimsy part really), or from dropping it and it landing there, or even in transportation or something bumping it from the side. The fact is I can't know what caused the USB port to break inwards, I can just offer suggestions and let them decide what to do with the info.

Actually I once had a hilarious couple with a broken keyboard + RAM. The fault there was that something was spilled on the keyboard that seeped down onto the RAM. I mentioned it to the wife of the couple and suggested that it smelled of maybe apple juice or white wine, and she went bright red and asked "Did my husband tell you to say that?" I said "um no...", and she begged me not to tell him, but yes she always takes a glass of wine and her laptop to bed with her, and was for sure she didn't spill. I told her that Everybody gets spills at some point, and there's also no proof it wasn't apple juice from a child, or someone else bumping her table. She took it well anyway!

 

I've only had CMOS battery problems with old computers (a couple of IBM Thinkpads) which gave an error during BIOS. I've actually been able to boot a the few test computers I've tried without the CMOS battery at all, and they simply gave the wrong date and time!

I've had to consider faulty memory slots in the past, but it's always turned out to be something else and I've never seen this situation before. I've since examined it with a magnifying glass to see if that loose part shorted any of the contacts or any neighboring components, but I can't see anything. I hadn't heard that faulty memory slots are getting more common - do you then think it could be unrelated to the loose part?

 

haha, looking back i did edit that out of my posts.. although i would most certainly have checked it in another computer so i'm not sure if i would have caught that a slot was bad... probably 50/50.. i guess it depends on whether or not i would have tried to turn on the computer with only 1 RAM module in.
Unfortunately won't help me with my KIA computer.. I've already checked the RAM and RAM slots.. doesn't seem to be the issue.. darn.

thanks for the fun game though!
*EQL*

 

Yeah, it could be completely unrelated, though it's hard to say for sure. Most mobo memory slots seem to just go bad randomly, without a cause for the effect.

 

Oh I also forgot to mention another bizzare result: since keeping the bad memory slot vacant, the laptop now boots from the battery! That very first time I successfully booted the laptop up I viewed the battery info and it showed 100%.

 

I sense an idea for a cartoon book in the works...

101 Uses For A Dead Laptop​

:-D