Computer shutting down

A business has 3 computer/registers at their checkout. When any of the registers printed an invoice the middle computer would shutdown. Now whether a computer shuts down or shuts down and restarts is important. The former is always a hardware issue and the later can be a hardware of software issue.

I initially thought that the middle computer was connected to the printer via a USB port but the printer was on the network. Unlikely but there could have been problems with IP addresses and a faulty Network Card (NIC) in the middle computer.

I had a closer look and noticed that all three computers have a UPS attached. UPS stands for Universal Power Supply and these are generally large batteries and when it detects an outage it will switch over to use the battery. More expensive UPS devices use the battery constantly and condition the power so it stays at 240Volts and 50Cycles (In Australia).

UPS devices do wear out however and I think that what was happening was that the power drain on the power circuit when the printer starts was tripping the UPS over to the batteries. Unfortunately the batteries were well and truly dead and so the computer shutdown.

I temporarily connected the computer into the power and it must have worked as I haven't heard a complaint.

Wet laptops

Laptops get all kinds of things spilt on them and they come in regularly. I recommend the following to give the laptop of fighting chance to survive a dunking or a spill. First is disconnect power and get the machine stopped as soon as possible. Don't worry about saving anything, hold down the power button until the laptop turns off. The next thing to do is to flip the laptop over, remove the battery and sit the computer upside down but open. The laptop will look like an A. This lets the fluid drain away from the motherboard.

When the laptop arrives I then take off everything I can from the bottom (RAM, Battery, HDD and DVD drive. I then remove the appropriate screws from the bottom and take off the top strip and the keyboard.

You can usually see the motherboard at this stage. I then hit the laptop with a hair dryer. I still leave the laptop for a day after this to make sure that all of the laptop is dry.

If the laptop has had coke or a sugary drink spilt on it, I usually then strip the laptop right down as coke will corrode the laptop. I then wipe the motherboard down with alcohol to remove all signs of cola and then again dry the laptop thoroughly. I usually can see at this stage if anything has blown and would need replacing.

Computer Not Booting (An easy one for a change)

A customers computer would not boot. It came up with an error NTLDR not found press Ctrl-Alt-Del to reboot. The harddrive wasn't making a noise which was good for a change and could be seen in BIOS. I set up BIOS to boot from a BART partition on my thumb drive. Most BIOS have two boot places. One to pick the device type order and another for the Hard Disk device order. When I restarted the computer would not boot from my thumb drive.

I went into BIOS again and notice that the first device to boot was the USB HardDrive. I changed this to last position and then booted again and the computer booted beautifully.