Overheating CPU

Our main home PC is an AMD Athlon MP 2400+ dual processor machine that we bought back in 2004.  I have kept it going all these years by replacing various parts as they failed: first the RAM, then the graphics card, and most recently the power supply unit.

Earlier this week we had a series of warm days and the PC started showing occasional spontaneous shutdowns while my daughter was watching videos. 

I opened up the PC box to check that all the fans were still working (they were) and noticed a flashing red light on the motherboard.  According to the motherboard User's Manual that came with the PC, this light flashing indicated a shutdown due to a CPU overheating.

I let the PC cool off and the flashing red light went out after a minute or so.  Then I booted up into the BIOS and went to the PC Health Status page.  This showed the following:

• System temp = 35C
• CPU0 temp = 60C
• CPU1 temp = 60C, rising to over 100C within 10 minutes

This is not good: I remember reading in some AMD document that the MP 2400+ CPUs should not go above 90C - 95C.

A bit of Googling and a bit or reading suggested two things I could do: remove any accumulated dust and replace the thermal conductivity layer between the CPUs and their heatsinks.

I carefully used a screw-driver to detach the CPU fans.  Both fans were full of dust and the aluminium heatsink grills beneath them were covered in a thick mat of dust.  I cleaned them carefully using one of my daughter's artist's brushes.  I also cleaned the case fan, the front ventilation grills (I had to detach two front panels to do this properly), and brushed and blew out as much dust from the case as possible without touching the electonics.

When I rebooted the PC and went into the BIOS  PC Health Status page it showed:

• System temp = 35C
• CPU0 temp = 45C, rising to 60C
• CPU1 temp = 60C, rising to 85C

An improvement, but not there yet: CPU1 was still 15C - 25C hotter than CPU0.

I walked over to our local Maplins and bought a tube of Antec Silver Thermal Compound.  I again removed the CPU1 fan and, following the unclipping procedure shown in this Youtube video, I unclipped the aluminium heatsink from CPU1.  Following the instructions that came with the thermal compound, I used some spare video head-cleaning fluid to clean the contact surfaces of the heatsink and the CPU.  Then I put a small amount of the thermal compound on both surfaces and, taking care not to get any on the surrounding electronics, I used a thin slip of clean paper to spread it smoothly, so instead of being opaque dark grey it was an almost translucent even light grey.  I then carefully clipped the heatsink back to the CPU and reattached the CPU fan.

On rebooting, the BIOS PC Health Status page showed:

• System temp = 35C
• CPU0 temp = 45C, rising to 60C
• CPU1 temp = 45C, rising to 60C

Problem fixed!

It has now been 24 hours and I have seen no reoccurrence of the spontaneous shutdown and, whenever I have looked, the temperatures of both CPUs have been within a few degrees of each other and in the range 45C to 60C.

Update on Thu 2011-08-04 by Tristram Brelstaff

When I looked closely at the motherboard User's Manual (GA-7DPXDW-P AMD Socket A Dual Processor Motherboard Users' Manual) I noticed that the illustration of the PC Health Status page shows the following:

• System temp = 31C
• CPU0 temp = 34C
• CPU1 temp = 88C

It looks like I wasn't the only person to have problems with CPU1 overheating!

Wacom Bamboo Pen on Ubuntu 10.04 LTS

Last year I bought my daughter a Wacom Bamboo Pen CTL-460 tablet. I quickly got it working with Gimp and Inkscape on our Windows-XP PC but was unable to get it to work at all on our laptop running Ubuntu 10.04 LTS. And that was how I left it, until last week when I came across this page at the Linux Wacom site.  What I hadn't been clear to me last year was that both a kernel driver (input-wacom) and a X11 driver (xf86-input-wacom) were necessary and that Ubuntu 10.04 LTS has only the X11 driver included.  Last week I simply downloaded and installed the kernel driver following the given instructions and now the Bamboo Pen works perfectly on the laptop too.

Update on Mon 2011-10-17 by Tristram Brelstaff

Every time you update the Linux kernel you need to reinstall the Wacom kernel driver.

Firefox ignoring /etc/hosts when DNS not available

I have a laptop running a development LAMP web server under Ubuntu 10.04 LTS.  The laptop is normally connected to a small network where the DNS name server is a modem-router with IP address 10.0.0.2.  The relevant parts of the network configuration files are as follows:

 /etc/resolv.conf:
 nameserver 10.0.0.2
 ...

 /etc/hosts:
 127.0.0.1  localhost laptop site.laptop
 ...

 /etc/nsswitch.conf:
 ...
 hosts  files mdns4_minimal [NOTFOUND=return] dns mdns4
 ...

 /etc/host.conf:
 order  hosts, bind
 ...

This all works as expected if the laptop is connected to the network and the DNS name server is available:  I can ping site.laptop and can also visit the site.laptop website in Firefox 3.6.17.  However, when I disconnect the laptop from the network and the DNS server is no longer available I can still ping site.laptop but in Firefox I get "Server not found" whenever I try to visit site.laptop.

I tried all sorts of things in my attempts to fix this problem, and learned a lot about DNS in the process, but nothing worked.  And then I remembered that a while back I had disabled IPv6 DNS in Firefox to fix a bug which was delaying page loads.  I reasoned that the bug that caused the delay might well have been fixed by now, so I entered about:config in the Firefox URL bar and then set network.dns.disableIPv6 back to its default value of false.

This fixed my "Server not found" problem: I can now get to site.laptop in Firefox with or without the DNS name server available; and the slow page load problem has not returned.

Norton Internet Security Renewal Experience

I have just renewed the subscription to Norton Internet Security (NIS) on our Windows XP Professional PC.  It took me nearly an hour of fiddling to do it in the way that I wanted.  Here is what I had to do:

1. I started from the NIS 'control panel' (Start > Programs > Norton Internet Security > Norton Internet Security) and in the Subscription Status section at the bottom clicked Renew.  In the Subscription window that came up I clicked Express Renewal. This started the web browser and opened a subscription renewal page at one of the Norton sites.
2. Here the NIS 2011 renewal defaulted to 2 years  (£74.99).  I only wanted 1 year (£44.99) so I manually changed this and continued.
3. A screen appeared offering to add Norton Utilities (£9.99) to the order.  The Yes button was large and colorful.  I had to look carefully for the No option: it was hidden as un-button-like "Keep my choice" text.  I clicked the latter.
4. The shopping cart came up with Norton Virus Removal Assurance (£6.99) automatically added to the order.  No asking, no warning, no explanation.  I deleted it by clicking the little dustbin next to it.
5. At the Billing and Payment page I noticed in the small print that I would be also enrolled in the Norton Automatic Renewal service.  In other words, I would be giving permission to them to take an unspecified amount of money from my account in a years time, and every year after that.  And if I didn't want to give this permission, or later wanted to withdraw it, I had to log into my Norton account and explicitly disable it. 
6. Now I personally have no difficulty whatsoever in remembering to renew my subscription when the time comes.  (As if I could miss the Norton pop-up reminders!)  But I was a bit worried that I might have forgotten the password to my Norton account, so I abandoned my order at this point and went off to see if I could remember it.
7. When I had managed to log in, I thought I might try to renew directly at the Norton site, rather than through the NIS Express Renewal button.  There I noticed that a new sign-up for 1 year's NIS 2011 was being offered for only £24.99.  I then proceeded to order this, avoiding several of the above traps on the way (not all of them reappeared this time, if I remember correctly).
8. The order confirmation email contained a product key which I cut and pasted directly into the Product Key field in the NIS Subscription window (Start > Programs > Norton Internet Security > Norton Internet Security > Renew).  The NIS 'control panel' now showed that I had 366 days of subscription remaining.
9. Finally, I went to my Norton account and disabled Norton Automatic Renewal service.

How do I feel about all this?  Do I feel pleased with myself that I managed to pay only £24.99 instead of between £44.99 and £91.97 that I could have paid had I trusted Norton?.  No I don't.  Instead I think "Why the hell didn't the Express Renewal button just go straight to the £24.99?  Why was I forced to jump through all these hoops just to renew my subscription?" 

Had I paid £44.99 or £61.97 or £91.97, I would have felt pretty stupid when I later saw the £24.99 figure on their web-site.  Companies that depend on repeat orders should never make their customers feel stupid for having done business with them.

PhpMyAdmin not working in Ubuntu 10.04 Server

Yesterday I installed PhpMyAdmin on my Ubuntu 10.04 server but when I came to test it out I couldn't get it to work: I just got a 404 Not Found page instead of the PhpMyadmin login page.  I searched the web and followed up several possible solutions but they all eventually just fizzled out.  Then the answer suddenly came to me while I was watching this video: I had omitted to select the configure for Apache option during installation.  I remembered just assuming that Apache would be the default and just hit Return without thinking, but watching the video made me realize that you had to explicitly mark Apache with an asterisk before hitting return.  Simple, and I am rather annoyed that I fell for this.