Inside Matthias Nott's Brain

I recently had my APC Smart-UPS 3000 RM report to me that I needed to replace the battery. Sure thing, I ordered a replacement from Ebay, plugged in and thought everything should be just fine.

Well, it wasn’t. The battery was not charged, and neither reset nor power cycling the UPS helped. Today, I was lucky enough to find this Video on Youtube:

http://www.youtube.com/watch?v=pAwMRn15z60

Fortunately, also, I was having an old 9 pole m-f serial cable which I happily plugged into the back side of the APS first, and then into my server’s serial port. At which time everything was powered down.

It of course helps to RTFM before the fact, so I saw this scheme:

And as I had a spare female serial connector (it helps to never throw those kinds of things away; I used to make those cables myself about 20 years ago) and of course a soldering iron, I modified the cable that I had accordingly.

Since my server is running on Linux, instead of using Hyperterm, I used minicom with the following /etc/minicom/minirc.dfl:

pu port /dev/ttyS1
pu baudrate 2400
pu rtscts No
pu xonxoff No

Under ubuntu, you can install minicom just like apt-get install minicom. Then run minicom as root, and it should connect you to the APC. If not, you can use minicom -o -s to modify the settings.

The idea from the above Youtube video in essence goes like this: You somehow use a terminal program to connect to your APC UPS, then

1. Press Shift+Y to get a SW prompt
2. Press 1 two times with about 2 seconds interval to get a PROG prompt
3. Press 0 to get a status, where everything except 8C is not what you want
4. Press – as often as it takes to get the status set to 8C
5. Press Shift+R to save and exit

In the Youtube video, it also says to use + to confirm the value; this was not working for me; + is just the opposite of -, i.e. it cycles the other way round.

In the comments to the Youtube video, I found a note that if you have an APC Network adapter plugged into the back of your UPS, then hitting those 1 two times at an interval of 2 seconds would not give you the PROG prompt. This was the case for me; I could remove the network card while the UPS was running, and got to the PROG prompt immediately after. After saving the value (Shift+R) I could just plug back in the network card; after a couple of seconds, I was able to reconnect using telnet or http as usual.

So bottom line: Make sure to build (or order) the correct serial cable.

Today’s one of those days where you start with a clear plan of what you want to do, and then you end up fixing something entirely different. Since I’ve built most of my virtual machines based on a small set of templates, at some point I got bored by having to keep them updated manually (and there’s a lot of them). So one day I switched them all to automatic updates.

Now’s the other day where all of them decided to throw errors. Basically, my boot drive was chosen to small, and the automated update process didn’t remove older kernel images.

Easy to fix, though I’ve to find a way to automate that (you’ve to make sure you’re running on the latest kernel, i.e. a reboot), if you use this script from the command shell (I found it somewhere on the net but have lost track):

dpkg -l 'linux-*' | sed '/^ii/!d;/'"$(uname -r | sed "s/\(.*\)-\([^0-9]\+\)/\1/")"'/d;s/^[^ ]* [^ ]* \([^ ]*\).*/\1/;/[0-9]/!d' | xargs sudo apt-get -y purge

Apple Mail seems to use its own location for downloading attachments that you double-click on. On my machine, this was in

~/Library/Containers/com.apple.mail/Data/Library/Mail\ Downloads

I wanted those to go into

~/Downloads

And since Apple as a company keeps thinking about even the illiterate, it hides the Library folder, and even if you unhide it for the Finder and create a “Shortcut”, it won’t work. So, open Terminal.app and do

mv ~/Library/Containers/com.apple.mail/Data/Library/Mail\ Downloads/* ~/Downloads
rm -rf ~/Library/Containers/com.apple.mail/Data/Library/Mail\ Downloads
ln -s ~/Downloads ~/Library/Containers/com.apple.mail/Data/Library/Mail\ Downloads

To fix that.

Interestingly, Apple Mail’s preferences did point to ~/Downloads all the time. But that’s used only when you do a “Save to Downloads Folder.”

Oh well…

I’ve had increasing problems with two MacBook Pro, one I5, one I7, both from 2010. Reading about badly applied thermal paste on the net, I decided to give that a try. Using this excellent walkthrough from iFixit.com, I was able to eliminate the problems entirely. Monitoring the I7, I can see that the processor temperature dropped from 60 °C down to hardly over 35 °C doing the exact same job. The fan’s are very silent right now. The whole process takes about 30 minutes if you do it the second time; the first time may take you like an hour.

So here’s some material that I used, all from iFixit (the only additional tool I used was a head lamp with a magnifying glass that I recently bought in a road-side store in Taipei). First of all, I used a Magnetic Project Mat. This really helps keeping all those tiny screws in place. Next, I used the Pro Tech Base Toolkit. Those screw drivers are really excellent, very good selection of bits, and excellent grip. Don’t even try with your 5$ selection of screw drivers from Home Depot… The spudger from the set comes in handy for removing all those tiny ribbon cables. The anti static wrist wrap should be a no-brainer for you. Then, I used the “pro” Version of the Probe Set. The tiny tip served very well to remove any remaining old thermal paste from in between of those resistors. By the way, there was so much excess paste on the NVidia Chip that it had run over the resistors (see images below) – one effect that I had was that when watching Flash movies, I had diagonal flashes across the screen quite often. That’s also history now. Next, I used Arctic Silver ArctiClean to remove the old thermal paste. The easiest thing is to use QTips to remove the old paste, as you can work very precisely with them – and thus avoid spreading the old paste everywhere. The removal kit comes with a solvent for the old paste, and once you’ve done that, you use the second component (they are labelled “1″ and “2″) to prepare the surface for the new thermal paste. Bigger bits of paste can be removed with one of the tweezers from the Pro Tech Base Toolkit. Following some guides on the net, for the first computer I applied the new thermal paste using a very tiny droplet of Arctic Silver Thermal Paste on the tip of my index finger that I wrapped into some plastic film. For the second computer, I used QTips wrapped in plastic film, which allowed even more precise application. Since the Thermal Paste is basically metallic silver, you want to avoid at all costs spreading it outside of the application area. I applied a very thin film on both the chips as well as their counter parts of the heat pipes.

Total cost of material used (except the lamp): 141.75 $.

Here’s the first computer after umounting the heat pipes:

As you can clearly see, there is much too much thermal paste, it is everywhere where it shouldn’t be, i.e. outside the chips but not really on them. No wonder that the fans were inefficient to remove the heat!

Here’s the same view, after removing the old thermal paste:

Then, with the new paste applied:

And here are the products used:

The second computer had the exact same problem. This confirms this to be a general problem with MacBook Pro’s:

Again, after cleaning:

This shows how (and, in particular, how little) to apply:

After application of the thermal paste:

So that’s all for now. While assembling everything back together, you can actually benefit from the occasion to remove the battery, pry the white lamp that stupidly keeps flashing when the laptop is in standby mode, and put some black adhesive over the lamp. I haven’t documented that, but you’ll find out yourself. The lamp sits in front of the battery, so you’ll have to remove the battery first (and you’ll need to remove the three very special screws for that; the right bit is part of the Pro Tech Base Toolkit); then you can use one of the metal spudgers of the same toolkit to remove the lamp. It is just glued there, but comes off pretty easily; it can be put back just as easily afterwards).

Hope, this helps…