TI-99/4A wont power on..

UK PAL model, plug everything in and flick the power switch, the power light doesnt even come on?

Ive checked the power supply for and dry solder joints and they all look fine.. ive opened the computer and had a look inside and everything looked ok, the power switch was moving the internal switch, and the power connector at the back goes to another internal power supply, ive not checked that yet however...

Anyone any ideas? :/