[Solved] My PC keeps switching off on start

[Tino1948]

Hi everyone. I am new in the Forum and I have all the tickets for a living nightmare: Man, old and foreigner.

 

I bought a second hand PC that yesterday and, when I did buy it, I saw it working without problems. But arriving at home and installing it, when I do switch it on, after 30sec switchs off itself. And this happens any time every time.

 

Can not be overheating issue because it has not chance to overheat anything in 30sec. The fan is working anyway. I can not perform any BIOS or whatever repair using the PC because I have not chance in 30sec.

 

My experience on nowadays PCs is very slim. I did start in 1973 with an IBM 360 30 Mainframe and while in London I used to go the Tottenham Court Road the weekends to the PC boot sales (Saturday in front of Tottenham Court Road underground station and Sundays in front of Warren Street station) and build my PCs but after 12 years in Hastings I've forgotten averything and my hands are not what they used to be. The ageing is showing up very, very fast...

 

I would appreciate if someone can help me to resolve this on 30 sec switching off problem.

 

With thanks in advance for your kindness,

 

Tino, the Mad Celt Galeg

[maynardvdm]

Hi

 

Welcome to Extreme Tech Support - Free PC Help.

 

First thing to try is make sure nothing has come loose transporting it. Make sure everything is secure in place. Next would be to try a different PSU, if you can borrow one to test.

[Tino1948]

Ta maynardvdm.

 

Tomorrow I'll go to the shop to get one and I'll try. It makes sense to me but, as I said, I have not too much knwoledge of these desktop PCs.

 

In any case, Why was working just few hours before in the other chap's place? I don't kow, but seems to me that nothing got loose in the transportation (I had a look inside), but at my age this means nothing, really.

 

Anyway, thank you for your tip. Have a nice one.

 

Tino

[Tino1948]

Hi again maynardvdm

 

And hi to anyone that could be reading this post just in case of that someone knows something new that we are missing.

 

I did several trials. I did repeat about 40 times the following:

 

I wait about 5 minutes, press the “on” button, the PC starts until WindowsXP attempts to start up by showing the logo and the running strip and then the machine switches off. I do try to turn on the PC but the second time and the following 14 times just switches off within 30sec. Stop for 5 minutes and the full thing starts again and again.

 

Why the first time reaches the Windows start up but not the others? If the CPU or MoBo are faulty I suppose that they will not allow anything since the first time, Isn’t it?

 

The 3 fans are working all the time.

 

I did open the case, unplug everything and plug it again (just in case of a bad connection) with not avail.

 

I did mount the full PC in a carton box with not avail (just in case of a short circuit somewhere).

 

I couldn’t see any condenser deformed or blacked by heat or with some leaking.

 

With a multi tester did check diodes, resistances and the input and output voltage values on the PSU and I believe that they are as they should be (I think…).

 

I am lost… My knowledge and skills are not up to the task, I am afraid.

 

Any new ideas?

Edited July 15, 2012 by Tino1948

[Plastic Nev]

Hi, I just recently advised on a similar thing, where from the first start up it took a few minutes, or similar to you, just long enough for the running strip to show up, but shuts down very quickly at the second or third attempt.

 

It was due to the heat sink having become detached from the CPU, with no heat sink connected, the CPU will overheat extremely quickly.

 

Considering you have only just bought it, I do think perhaps it has loosened in transport, however I would suggest taking it back as it isn't as you saw it first and running OK.

 

If however you are willing to first remove the fan, and then find whatever clips or screws, fix the heat sink in place, some are clips, other makes are screws, and correct them if they are loose.

 

If so and it is loose, before refitting, first you need to clean off all the original thermal compound between the heat sink and CPU, then apply fresh compound before fixing the heat sink securely, and then the fan.

 

Nev.

[ukbobboy]

PC Keeps switching off

 

Hi Tino1948

 

Your problem sounds to me like your WinXP has some sort of instability, such as the memory chips, motherboard, etc, so I have the following suggestions:

 

1) Try starting your PC in safe mode, this may or may not work, but it will give you some indication of what may be wrong.

 

2) Try re-installing WinXP from a boot disk, again this may not work but if it does you will have a stable copy and workable O/S on your PC.

 

3) If nothing works then you will have this final choice, take your machine to a PC repair shop, get a quote on how much it will cost to repair then decide if the cost is economically worth it.

 

 

UK Bob

Edited July 15, 2012 by ukbobboy

[Synapse]

It was due to the heat sink having become detached from the CPU, with no heat sink connected, the CPU will overheat extremely quickly.

 

This is where I would start based on how you have described the fault.

 

The first boot from cold will take longer to warm the system including the CPU heatsink. Each reboot from here will add heat to the system and if the CPU heat is not dissipated quickly enough, the system will shutdown to prevent damage.

 

Look carefully at the CPU heatsink and fan, foliow Nev's advice, if you get stuck, please come back for help.

[Tino1948]

Ta Plastic Nev, ukbobboy and Sypnase.

 

I think that I need to become a magician to do all that in 30sec… I don’t know… Do you think that I can be that fast ukbobboy? In the other hand, every time that I hit the keyboard the “thing” shuts down too so…

 

I believe that Plastic Nev and Sypnase have a point because, on spite of being careful in the transportation, after the stroke I am not too stable as well as that the box was only 16Kg (tower, keyboard, VDU and mouse) but these days 16kg to me feel like 160 (and only 5 years ago I was moving 30 pallets of half ton each every day plus at 6am I used to have 100 miles in my back and now… Very depressing…), so the box got a “bit” of shaking so that something got loose makes sense to me.

 

I am too tired now to work safely on the PC and it is too late but tomorrow I am going to do what Plastic Nev said and fingers crossed.

 

I will keep you updated on how the “thing” resulted since all of you have been so kind to help me. It is the less that I can do.

 

Thank you and good night to every body.

 

73 Plastic Nev.

 

Kind regards.

 

Tino

 

 

 

(Why on Earth I need to sign in twice to answer your answers? One to get into the Forum and other to answer… ?????)

Edited July 15, 2012 by Tino1948

[KenB]

Why on Earth I need to sign in twice to answer your answers? One to get into the Forum and other to answer… ?????

This is not normal - once you have signed in you should not need to sign in again to post a reply.

 

When you sign in do you check the box to "Remember Me" ?

[Tino1948]

Hi KenB

 

Thank you for your commet.

 

Not I never tick that bos enywhere, not in any Forum, not in Skype, not in Microsoft Live... nowhwere. It seems to me not safe to do so. And less in anything from Microsoft... Actually in my PC I have WindowsXP for particular things and Obuntu Linux and AppleMac OS X Lion for business.

 

So when I sign in just go to the XP part of the Forum, I open my post and then I do try to answer the last advise, I do write the comment adn when I do click on "Post Quick Replay" ad notice tels me that I am not authorised to do so adn I need to sign in whe already I am signed in. I need to sing in again and write again de full comment.

 

After all this happenings, I do write the comment in a word document (like this one actually), copy and pst it in the Forum and when fails I don't need to write again, just copy and paste again snd the second time goes out.

 

What I am doing wrong this time? (as usual... not news... I am getting old too fast...)

 

In this moment I am working in the troubled PC doing the advise by Plastic Nev and I took a breake to have a cup of coffe and to see what was going on in the Forums and I did find your commet.

Here we go again!!!:

The following errors occurred with your submission

 

1. You do not have permission to perform this action. Please refresh the page and login before trying again.

You see? So this answer is the second one as usual…I did refresh the page and did log in again and did post this answer again…

[KenB]

Hi

 

What I am doing wrong this time?

Absolutely nothing - I have just heard from synapse (moderator)and he has the same problem as you.

 

I always use the "Remember me" box - which will put a cookie ( harmless ) on your system.

[Tino1948]

Yes… The heat sink was totally loose…

 

This heat sink have not only 2 clips or 4 normal screws as most of them, but 4 press-and-turn vertical bolts that fit into the MoBo.

 

After re fitting the heat sink and checking again all the plugs and connections, still keeps doing the same on its own, I mean even with not VDU, keyboard or mouse plugged.

 

Any suggestion?

 

Kind regards.

 

Tino

Edited July 17, 2012 by Tino1948

[Tino1948]

Ta KenB

 

This time I tick "remember me" and seems to be working... ??????????????? Should not be like that, I think...

 

Anyway, fingers crossed, it is working now.

[KenB]

The heat sink was totally loose

You probably need to take it off completely - clean the surfaces with rubbing alcohol ( from a pharmacy ) and replace the thermal paste ( Arctic Silver or similar )

The thermal paste only needs to be a very thin layer.

 

=============

 

This time I tick "remember me" and seems to be working

It is cookie related.

You now have a cookie ( small piece of software ) on your system from this site.

It may have been related to your privacy settings - either way ...............hopefully it is all ok now.

[Tino1948]

Ta KenB

 

Yes... Plastic Nev told that but I did run out of thermal paste, I thought that still had enough (I know, I kown, nobody is perfect. Sorry Plastic Nev...) and just put it back, but obviously (as expected) didn't work, needs to be cleaned. That's why now stays a bit longer without switch off.

 

Tomorrow I'll go to the shop and buy some and I'll fit it again.

 

I'll keep you update.

 

All the best

 

Tino

[Plastic Nev]

Hi again, once disturbed, even if fairly fresh, old paste should be removed and replaced. A bit like an engine gasket, best to replace it as the old one will never seal again.

At least we are getting somewhere and the heatsink had come loose, let us know how you get on.

 

Nev.

[Tino1948]

Hi Plastic Nev, KenB, mayarddvdn, ukbobboy and Synapse.

 

Problem resolved. Not only the heat sink was loose but also the fan was damaged and didn't spin at the right speed. I did change the fan, put new thermal paste, fit the whole heat sink and is working properly (so far... fingers crossed... always learning).

 

Thank you every one for your help. Nice one.

 

Tino

 

 

http://extremetechsupport.com/images/statusicon/user-online.png

[KenB]

Problem resolved.

That is good to hear.

 

Good result from a team effort :)