Help - Acer Aspire 5742G - Does anyone know what this cover is on the GPU?

Skybluesky

Hello Everyone,

I opened my laptop to clean it and noticed that the clear cover over the GPU seems to be peeling or lifting (photos attached) - much worse than it was before. Due to excessive heat is my guess.

There seemed to be some glue beneath it that is now dry or gone.

Does anyone know what this clear cover is made of and how I can replace it? Or what glue is it? Some type of flux maybe?

I´ve been having many problems with the graphic card and getting many blue screen warnings. I also noticed some signs of slight oxidation on metal parts like the usb connectors and a few screws from the heatsink.

And I think this is the Intel chipset (with the same problem):

Does anyone have an idea of what this is that can help?

Thank you and best regards.

JackE

Anything that seems 'springy' or 'springs back up' when depressed down might be a momentary switch. If you haven't done so already, I again suggest trying to download the mainboard diagram by googling the keywords 'Compal LA-5891P - Schematics. Download Free' Then compare it with what you have up close. It's difficult for me to do this on-line without having the actual board in front of me.

If it was mine, I wouldn't use the thermal pad or mylar side cover on an older AMD & Intel based mainboard, I instead use hand-kneaded thin (about the thickness of a dime) pieces of gray electrician's sealing putty covering the entire surface of the processor. When squeezed between the CPU & heatsink, excess putty doesn't flow over nearby components as easily as thinner pastes do. The resulting putty layer stays put & sticks well to both surfaces with no voids for fairly good thermal conductivity. It also doesn't dry out as easily as pastes. It's usually sold in half or one lb bricks in the electrical dept at the HomeDepot or Lowes.

JackE

I´m looking for the number of this ribbon cable, to see if it may be this.

Number is printed on the ribbon itself. It's a quite common Toshiba part Hamburg-SH E235863. Google the part number to find a vendor who ships to your location. But I don't think it's the problem since the mainboard wire connector contact shadow on the ribbon conductor seems to overlap what's left of the conductor. However, new ribbons are pretty cheap so it's up to you if you want to try replacing it to see if it makes a difference.

JackE

OK. The folds are normal. But google the part number again from your location for vendors who might have a better image of exactly what you get. If the board isn't already attached, the other end of the ribbon should slip into the button board in a similar wedged way, not glued. As for manuals and drivers for older WinXP/Vista era models, 3rd party sources such as manuals lib dot com should have them.

JackE

It´s easier than soldering

Maybe. Maybe not. Depends on if the board is included. Not a 100% certainty unless a vendor says it is.

Note that the manufacturing date stamps on your old board & cable are different. Which may or may not mean they are sold separately and must be assembled (soldered).

It's a gamble. But I think the price is low enough to justify a try. Good luck.

JackE

12/11 Anyone has any ideas as to what could be the reason it starts and then shuts down? But at least now it connects… :(

11/06 This time it didn´t even connect then shut down again.

The above comment you made last month —- "shut down again" —- suggested that you're now back to almost where you started this thread after experiencing many blue screen episodes. Accordingly, my best guess is that the GPU has finally failed with an internal short from repeatedly being overheated based on your very first opening comments in this thread.

New mainboards for this model seem to be available for less than $50usd from Aliexpress if you're willing to wait about 4 weeks for delivery should their stateside warehouses not have them in stock.

Skybluesky

… I think I´ll give up on this one. :(

Anyway, thank you very much for replying.

JackE

It's called a thermal pad to help cool the inductors and other components surrounding the GPU chip. Usually about 1mm thick. New pad material is available from Amazon. Or you probably can re-use what you have.

The pad may have had a layer of pink or white thermal paste (not glue) smeared on the bottom to help keep it in place during heat sink thermal module assembly. The thermal paste on the pad and GPU dries out after a while so it should be replaced with a good thermal paste like ArticMX4 or Kryonaut, also available from places like Amazon.

Skybluesky

Hello,

Thank you for replying.

I know it may seem logic, but are you sure it is thermal pad?

I was asking about the clear, transparent, acetate like layer that covers and surrounds the central part of the chip (where the yellow arrow is pointing)? Maybe you could be right but these don´t look like the usual pads and they have a plastic like cover on them.

All thermal pads seem to be opaque like the photo below.

"(…) The pad may have had a layer of pink or white thermal paste (not glue)
smeared on the bottom to help keep it in place during heat sink thermal
module assembly. (…)"

Like this one (photo from the internet)? Or just paste?

Originally, mine had thermal paste on the central part of the chip (where you see the toothpick pointing) , which I replaced with Artic MX-4.

I remember I replaced thermal pads on some other parts of the motherboard because they were breaking down, but these looked clearly like thermal pads.

JackE

Sorry, didn't seem too clear/transparent in the image. Probably Mylar then with thermal paste on the bottom. Mylar is a lot more heat stable, tear-resistant & durable insulator than a pad. It can be re-used. The GPU itself should only have a thin layer of thermal paste (spread more evenly than it appears in the image) to fill the gap between it and the heat sink.

Skybluesky

Ok, thank you. I had undestood (years ago) that you should only place thermal paste on that center part, the GPU itself, and not surrounding it.

SO, just to be sure I got it right:

it is ok to place thermal past all over the chip/card as long as the center only has a thin layer? AND then cover it with that mylar type layer?

JackE

Sure if the Mylar used still has the chip opening.

Skybluesky

Alright. By the weekend I will be able to open it and try that - I´ll see what I can do and post the result here later.

Hard to notice your bold letters!

Skybluesky

Hello again,

So I opened the laptop and did as suggested:

cleaned the old thermal paste and sticky stuff /"glue" with isopropyl acohol, then replaced thermal pad in the places where there was that plastic "mylar" thing (above the gpu and the chipset). Replaced the thermal paste, same place where it was before, and assembled it back again. Turned the laptop on and… nothing. This time it didn´t even connect then shut down again.

Re-opened it and checked if anything was disconnected - nope. Then cleaned the excess thermal paste (I put too much the first time), checked the fan, checked every cable and reassembled it back again. Still doesn´t connect. :(

I´m sure the thermal paste is not in excess, and I think I can say the thermal pad seems to be the right height as I was able to close the laptop and assemble it and it all seemed to fit fine, no gaps. I don´t know what is wrong. It used to turn on and disconnect, now not even that.

Anyone has an idea of what it could be wrong?

Before thermal pad replacement (this is a chipset, I think):

After thermal pad replacement (chipset and GPU):

JackE

Did you disconnect battery pack from mainboard BEFORE you re-pasted?

Did you fully tighten bottom cover screws when you completed re-pasting?

Skybluesky

Hi, thanks for answering.

I´m sure I did on both.

JackE

Remove bottom cover again.

Search around the perimeter of the RAM modules for a small springl-oaded push-button switch. Some mainboards have this safety switch. It must be fully depressed by a properly aligned and tightened bottom cover.

If not depressed properly by the bottom cover, all power to the mainboard is cut as a safety precaution.

Skybluesky

Ok, I´ll check it tomorrow when I open it, but I can´t see anything that looks like it from the photos I have right now. Not near the RAM modules.

Any clue of what it may look like?

CMOS battery?

I´m also wondering if a difference of 0.25mm or even 0.5 mm may make a difference in the thermal pads to the point that it wouldn´t turn on. I got the impression the pad was just slightly above the GPU chip, but such a small difference that is maybe not bigger than 0.25 mm.

Also, by the old photos I got the impression that the chipset had (maybe) a pad that stayed below it´s own height but now has a pad of 1 mm that stays right at it´s level. The original pad had long disappeared so I can´t be absolutely sure.

JackE

Yes, looks like the lithium coin cell.

Google search the keywords 'Compal LA-5891P - Schematics. Download Free' for the mainboard diagram.

brummyfan2

Hi @Amiya,

Do you still have the thin plastic you originally had? If so, remove the thermal pads around the CPU, it could be too thick and heatsink is not making proper contact, it's only a cover to protect other components from overflow of thermal paste.

Skybluesky

So I opened it again and checked everything and the only thing similar to a "small spring loaded push-button switch" is this:

Here on the last photo you can see it on the side. The arrow is pointing at the RAM modules which are right on the other side. If this is what you mean, I think it sits fully depressed. The cover was also well closed on this spot.

Don´t really know what you mean by "switch" as I couldn´t find anything like a switch elsewhere.

The only place I noticed a raised upper/lower cover was on the GPU/ heatsink area, far from the RAM modules.

Maybe 1 mm pads is too much? The cover was tightly closed except maybe for the GPU area. Could this make a difference and prevent it from connecting? It´s a 0.25mm, maybe 0.5mm difference.

I´m thinking of getting a thinner pad but unsure of the thickness I should choose. Either 0.75mm or 0.5mm. I´m also unsure this will make the difference. I´ll have to try.

JackE

It is a tiny, spring-loaded normally-off, push button safety interlock switch. A normally-off or momentary switch means that the spring keeps the switch off if no pressure is applied to the pushbutton. An example location near the RAM modules is shown below. Sometimes the factory omits the switch to save money and only an empty solder pad is visible where the switch would be otherwise located.

AnhEZ28

@Skybluesky

The tape that was on the GPU/chipset is a masking tape or Kapton tape. It is for protecting the small capacitors that sit around the die. Do not use the thick thermal pad as it could interfere with the gap between the die and the heatsink. You can use an electric tape to cover it or just leave it exposed.

Before putting the battery back in and the charger unplugged, hold the power button for 10 secs to cycle the power.

Skybluesky

@JackE and @AnhEZ28 thank you for replying.

I´m sure the cover has a bit of difficulty closing around the area where the GPU stands but not around the RAM Modules. I also checked old photos and I´m sure, whatever pad was there, it was thinner than the current new one. Such a difference that I´m thinking I will search for a pad with 0.5 mm.

Can anyone tell me what conductivity value is best? Would it be alright with something like 15 W/mk, or above, for this laptop model?

My other doubt is also the hardness of the pad. I got the impression that the older pad did no leave an indentation in the masking tape cover and the current one, left a few indentations in the "plastic" mask made by the capacitors around the die. Maybe because 1 mm is too much or the pad is too soft?

Still I can´t find that switch 😐️ I see nothing similar around the RAM modules and everything in that area seems to be well attached, I couldn't find anything like a switch or button. I will try again later. I´m going to search this a better.

Is it the SWG1?

Thank you!

JackE

Anything that seems 'springy' or 'springs back up' when depressed down might be a momentary switch. If you haven't done so already, I again suggest trying to download the mainboard diagram by googling the keywords 'Compal LA-5891P - Schematics. Download Free' Then compare it with what you have up close. It's difficult for me to do this on-line without having the actual board in front of me.

If it was mine, I wouldn't use the thermal pad or mylar side cover on an older AMD & Intel based mainboard, I instead use hand-kneaded thin (about the thickness of a dime) pieces of gray electrician's sealing putty covering the entire surface of the processor. When squeezed between the CPU & heatsink, excess putty doesn't flow over nearby components as easily as thinner pastes do. The resulting putty layer stays put & sticks well to both surfaces with no voids for fairly good thermal conductivity. It also doesn't dry out as easily as pastes. It's usually sold in half or one lb bricks in the electrical dept at the HomeDepot or Lowes.

Skybluesky

@JackE

I suspect this Acer Aspire 5742G has no such switch!

The electrician sealing putty is an interesting idea… where there are no thermal pads selling. Conductive or non-conductive? Cause I don´t understand much of it.

Unfortunately, I think my skills at kneading putty are not that good enough for making a dime thick layer. Also, I suspect it´s needed less then that of thickness. It´s easier to go with thermal pad.

Still it´s a good idea - I will keep that for another day.

JackE

I think my skills at kneading putty are not that good enough for making a
dime thick layer. Also, I suspect it´s needed less then that of
thickness.

Thermal putties and pastes should be good electrical insulators but good heat conductors. Many are based on silicate clays of which electrician's sealing putty is an example.

Special skills are NOT needed for kneading putty. It's simply shaped between your forefinger and thumb. The final thickness is of course less than the thickness of a dime! When you tighten the thermal module screws, the clay automatically compresses & assumes the thickness needed to fill the gap between the CPU and heatsink.

Thermal putties and pastes are much more forgiving than thermal pads in assuming the correct thickness between the CPU and heatsink. That's why it's more critical to choose a certain initial pad thickness than it is for an initial putty thickness. Yet another reason to choose a putty or paste instead of a pad.