Monday, February 8, 2010
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.