Laptop Testing
The Laptop Testing shelf is located in the far corner of the room from the entrance. There are a handful of ethernet cables for booting to the network, as well as a few long power strips for charging batteries. When you put a system on the Testing shelf, MAKE SURE YOU KEEP ITS AC ADAPTER WITH IT (even for Battery tests)!
Memtest
After a laptop has been deemed fit for building out, we want to ensure the memory installed is still good. Hence, Memtest.
A laptop successfully completes Memtest if it makes 3 passes without error. Periodically check on the systems running Memtest to see if any errors are reported. If so, make note of where in memory the errors occurred. Occasionally, you can infer which stick is bad based on where the error occurred, and save a stick of RAM. Consult your Instructor if you have any questions.
| STEPS | NOTES AND DETAILED DESCRIPTION |
| Install the proper amount of RAM | Check the specs on the whiteboard and confirm with your Instructor that the appropriate amount of RAM is installed. You should only be running Memtest on the following types of laptops:
As-Is machines go straight to the Store after being outfitted. |
| Run Memtest | Depending on the system, there are a couple approaches we can take:
Boot from Network
Boot from HDDIf you've already installed an imaged hard drive, then Memtest is available on the local disk. Follow these steps:
Boot from LiveCDIf the laptop you're working on doesn't support network booting and there isn't a hard drive available, you can try booting off of a LiveCD. There are a few available on the workbench, sometimes even a dedicated Memtest Boot CD. In general, once you boot from the CD, you should be presented with a list of boot options. Try and find Memory Test (memtest86+) in that list. If it's not there, try another boot CD. As always, if that doesn't work, consult your Instructor. |
| Troubleshooting Memtest |
Memtest FreezesSometimes you'll get Memtest loaded onto a machine, blue screen and all, but it won't indicate any activity. The newer versions of Memtest are incompatible with certain older chipsets in laptops. The work-around we have available is to use an earlier version. Unfortunately, this is only available on the Network at the moment.
Misreported Available Memory
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Battery Test
Once an imaged hard drive has been installed in a laptop, we can test its battery. This can happen either before or after the laptop has been built out, but needs to occur before its QC.
| STEPS | NOTES AND DETAILED DESCRIPTION |
| Adjust the Power Settings | These steps are covered under the Laptop Build Checklist:
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| Make sure the Battery is Charged | You can either hover your mouse over the Battery Icon on the top panel or, more reliably, type the following into a terminal:
$ cat /proc/acpi/battery/BAT?/{info,state}
Note that some manufacturers use odd names for the batteries (e.g., C167A). If you get an error with the previous command, either run This will tell you how much charge the battery is rated to keep, as well as how much charge it had the last time it was full and what its current charge is at without attempting to guess how long the battery will last (Ubuntu is notoriously optimistic in its estimations). Here's some example output: present: yes design capacity: 56160 mWh last full capacity: 49200 mWh battery technology: rechargeable design voltage: 10800 mV design capacity warning: 2460 mWh design capacity low: 200 mWh cycle count: 0 capacity granularity 1: 1 mWh capacity granularity 2: 1 mWh model number: 42T5262 serial number: 35098 battery type: LION OEM info: SANYO present: yes capacity state: ok charging state: charging present rate: 0 remaining capacity: 47800 mWh present voltage: 11243 mV Here you can see the remaining capacity is just a little bit below the last full capacity, but that the battery is reporting charging at a rate of 0. This can be attributed to the natural degradation of the battery, and so this should be good to test. Bear in mind that sometimes the firmware will lie, and represent numbers that are not at all accurate. The above is primarily meant to be a way of gathering clues as to the health of the battery. Remain vigilant! |
| Running Batterytest | There are two ways you can run a Battery Test:
Method 1: Playing a CD
Method 2: While loop
$ while true ; do stress-test ; sleep 300 ; done This will tell the computer to run a Make sure that you leave the AC Adapter with the laptop on the shelf. This makes it easier to check the results of the battery test and move it along the production line. |
Badblocks
Occasionally we'll get a laptop (especially netbooks) where it is exceedingly difficult to remove the hard drive, or the hard drive has an incompatible adapter with our imaging stations. When this happens, we can wipe the hard drive while it is inside of the computer and then install Ubuntu on it.
| STEPS | NOTES AND DETAILED DESCRIPTION |
| Adjust the Boot Order | It is imperative that we not boot from the hard drive before it has been wiped. The first thing to do is boot the laptop and set the Optical drive and, if available, Network device first in the boot order. |
| Boot into a Live environment |
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| Running Badblocks | Once you have a console up, type the following:
$ sudo badblocks -wvvf /dev/sda -c 1024 This will start writing arbitrary data to every sector of the harddrive, making five full passes with different patterns each time. Note that this procedure will take a long time (somewhere along 3-5 hours). |