Thinkpads Forum

Don't know what happened, but after over 4 years since I've that pc, since yesterday kept not starting and going into protection.
I've just opened it, thinking it was the psu.. and I've seen what seems termal paste (color and consistence) spread between the cpu and the chipset heatsink. In part is soft, and I'm removing it.. but on the bottom is more hard.
How to clean without damage ? it's all over some SMT resistors, and I suppose it's causing a short and all my problems.

I think I would give denatured alcohol a try - either 90% rubbing alcohol (isopropanol) or shellac thinner (methanol). Shellac thinner is probably stronger.

But before you do anything, wait and see if someone else replies with personal experience in doing this.

Ok,

meanwhile first update.. I've removed by hand (with a toothpick.......) all the thing. What's left is a very thin coating over the area (around 1cm2). There were more than 6 smt resistors under it, and now are colored silver, but more or less clean between them.
I've tried to turn on.. and worked immediately. Now is doing dos based diagnostic loops checking cpu etc etc, and apparently up to now (over 1 hour) all is PASSED except for a failure related to the Sata controller (but has never been used in this pc, so actually I don't know if it has ever worked... got this pc used, and never cared about the 2 sata ports on it).

I'm wondering if this means I've been lucky and can simply ignore to clean the rest...

2nd update.

Looks like I've spoken too quickly... it's starting to do it again (protection)

I use Goof Off. Note that there are other products with "goof" in the name that have fragrance and stuff that you do not want.


What do you mean by "protection"? If there's a short, usually it either doesn't turn on or something gets burnt/ruined. So if it's turning on then I do not think that's the issue.

Well, actually the psu and cpu fans start, then after some seconds all stops like if an emergency breaker kicks in.
This X times in a row, than it would boot...

On one boot the asus bios started saying : keyboard defective. Changed the keyboard.. worked briefly but at the next reboot back to the beginning. Attached the keyboard thru an usb dongle.. same. (the older keyboard works, I've checked).

I've read that some thermal grease are also conducing current (and I don't know what grease was this), and this is the reason i focused on cleaning. I wonder if this could be just a waste of time and what i've read just a plain [censored].
After removing the most of it (wonder how got there after 4 years....) the pc booted and i've started dos diagnostics using a boot cd. While using a 2nd software it shut down, and back to square 0.
Options :
1)psu defective
2)grease causing a short
3)thermal grease missing / no more working under the cpu heatsink
4)some device inside starting to drain too much power from the psu, causing it to shut down.
5)a combination of all this

While I'm still messing with this thing, i've managed to speak with an online friend who works as support for the central bank of portugal.
Apparently there's one liquid that's safe to use directly on electronic boards

WD40

www.wd40.com

Yeah, WD-40 is safe. The question though is: is the material you are trying to remove solvent-based or alcohol-based? WD-40 works well on solvent-based adhesives, etc.

Mah, not sure at all about the composition of that material since I was not the one using it years ago.

mazzinia wrote: 5)a combination of all this

Could be, that is why you have to eliminate one by one. Number one is a good place to start by borrowing from your assembled desktops. Also, I have cleaned AS5 from my cpu modules using isopropyl alcohol and sometimes with tapehead/contact cleaner which I always keep handy. Be sure to apply back heat sink compound else you risk thermal cpu failure/shutdowns without it. Good luck and let us know .

Up to now things are turning out funny. Funny because the whole problem started when I tried a new keyboard and then plugged back the old one.
Funny because initially gave the impression of being a ps/2 socket defect, then a shorted keyboard, then the persistence and random condition led to opening the case and finding that strange chunk of what seems thermal paste lying on the mb where I remember clearly nothing was.
Funny because disconnecting the HDs lead to a system powering on correctly and rebooting or hanging after being stressed for over 1 hour... and reconnecting one hd power cable caused the pc to simply go into protection.

So... 12V line on the psu is probably failing. I've still the old psu (removed because was starting giving too few wattage on one line of cables) and with that one back installed, all works since hours.

Funny because NOW after 1 month and a half of being stored away, that old psu works like not having problems... I wonder how it fixed itself...

Remember Murphy's laws.... all happened at the same time...

Thermal paste doesn't just appear like that. Sure a capacitor didn't pop or something?

Pretty sure, it's the first thing I've checked (being that one an asus mb, and remembering they had problems related to a bad batch of capacitors time ago).

Unless... and I underline unless, this thing was coming from the psu (that has a fan on the bottom part). But the psu looks clean (aka not having obvious traces of this material on any opening). Still.. if coming from here the trajectory would have been absurd