Google found...
http://www.fixyourownprinter.com/forums/inkjet/69647 Quote:Re: Canon MX7600-sensitive to power bumps? by Dubhlaine
Yes, i for one believe there is an issue with the power supply in these printers. I have replaced two power supples in this printer, one under warranty and another myself. I purchased after warranty expired. I found it online for around $70. Since then I have only used it on a battery backup surge protector, since that protector has its own voltage regulator and maintains a constant voltage even if your power in dies...the power adapter p/n is QK1-3484-000 and can be ordered from a few outlets. I ordered it here
http://www.dsnproducts.com/ but had some issue with their website since the number I clicked on (and ordered) changed somehow. So i had to return and order again so beware...
That part number might be for the USA version. UK might be different.
More googling found this but please check it's the right one and buy at your own risk.
http://www.crc-tasktron.co.uk/gbu0-prodshow/MX7600PS.htmlSome web sites describe it as a "clip fit mains adaptor". If the power supply is some kind of plug in module it might be worth removing the one you have and checking the contacts or however they get power from the module to the main unit?
Although it might be nothing to do with the power supply.