Main Board Removal Problem - Stuck Screw

I apologise for this post, but I am at my wits' end, or it feels like it.

I know this issue is going to be a very general one; I have encountered it specifically in regard to a laptop. I suspect other, more competent people have come across this problem in their laptops, and overcome it.

How do I remove a screw that is stuck ?

It's an M2.5x5mm (small) Phillips head screw that is the last one holding the main board of the computer I am working on in place (I hope).
I have tried some of the methods which have been suggested for removing g screws to no avail (the screw head is not projecting enough to get pliers around it [probably a good think), use of penetrating oil to loosen the screw [which probably was not a good idea], etc)
I don't want to do anything more violent to remove it nor do want to strip the cross-head patterning (anymore than I may have done already). All the guides I have seen show how easy it is ! indeed the other two similar screws came out more easily. But this one is stuck fast.

Dumb_Question
1.April.2019
HP Pavilion dm4-1050ea - Windows 7 Home Premum

 

Sure it's not a JIS screw? Phillips drivers don't fit them 100% and can damage them.

 

Yeah, sadly, it is not uncommon for manufacturers to use uncommon screw types just to dissuade users from doing their own maintenance. While this is partly to avoid warranty fraud (users breaking the product through misuse/abuse then attempting to get free warranty support), I feel they also do it so we (consumers) will be forced to use their very profitable service centers and their very profitable replacement parts.

Hopefully satrow's suggestion to try a different driver type will resolve the issue.

If not, is the screw head already stripped? If so, you may need to drill a hole in the screw then remove it with a screw extractor. The problem here is metal filings on your electronics. It is almost impossible to avoid it. So a thorough blasting with compressed air to ensure none remain would be prudent.

 

Thanks for your answers, Satrow & Digerati. I had never heard of JIS screw heads before !
(not surprising).
I quote the HP maintenance and service manual:
"Remove the three Phillips PM2.5×5.0 screws (1) that secure the system board to the computer.", of which the problem screw is the last.
These are the larger of two sizes of screw (M2.5) which fit a Phillips screwdriver #1 (the other is M2.0 for which HP say to use size #0 screwdriver). These screws, although only of two Phillips sizes used in the laptop, come in more than head size and length in the laptop.

The head may be damaged, but there enough of the pattern remaining to get good purchase with one screwdriver, a jeweller's screwdriver, hence not very much torque, that I have (the proper Phillips #1 which I bought do not seem to fit !)
The head only became damaged (my lack of skill aside),if it is, through the screw being stuck in the first place because the other two came out quite easily.

AFIK this screw had never been used except when the laptop was first assembled. I will remember your warning, Digerati, about the care needed with metal filings when using a screw extractor. I don't like the thought of using a screw extractor because I always experience difficulty with keeping drills central when drilling holes, and for me it sounds like a good way to destroy my mainboard

Dumb_Question
1.April.2019

 

I hear you. Maybe you can find someone with a drill press (or hand drill press adapter jig) so you can ensure you drill down straight.

That said, you say you don't want to destroy the mainboard, why are you trying to remove it?

 

That's a good thought (find someone else...)

I am trying to remove the main board (in fact this entails the disassembly of virtually the whole of this model of laptop) simply to clean the dust from the fan. I am not certain that this was the cause of the overheating, but I had certainly been putting it off for quite a while. Of course I tried blowing air into the ducts first.

I also thought, while I had the laptop in a state of disassembly, that I could upgrade the CPU (core i5-430M), because that seemed to a very little job and I've replaced CPUs before, though not in a laptop. I know you are thinking why don't I just buy a new up-to-date laptop with gen 9 core CPU: please don't ask !.

dumb_question
1.April.2019

 

Well, good luck with your project. No doubt it will be a good learning experience.

 

Thanks, Digerati ! A learning experience was, in fact, partly one of the considerations.

Dumb_Question
1.April.2019

 

Have you tried the Phillips driver/rubber band/screw sandwich yet?

 

Hi Satrow
no, I haven't. I remember reading about that but it must have slipped my mind to try it. Thank you for reminding me.
I was thinking that I might as well try to unscrew it and damage the head pattern as it is going to have to be removed anyway. I just wanted to try reinserting and tightening all the other screws around it to see it that would relive the tension.
Thanks !

Dumb_Question
2.April.2019