It has been replaced with a more modern cyber-secure PC (i.e. one that supports Windows 11 as this is a 4th Gen i5) so although technically it's not worth repairing, I would like to use this as a training opportunity to see if (with your help) I/we can fix it as that way I can learn something from a computer with a genuine fault...
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On plugging it in to my bench power supply it starts to draw around 160mA whereas from the other Ultra Compact PCs I've successfully fixed it should...