Hello again -
I have re-capped, replaced transistors and re-soldered all the input/output connections on the power board and the machine now works as it should and is firing on all cylinders. However.......
When I first removed the bottom cover there were two loose pieces of aluminium strip lying on the circuit board. I do not have the skills to upload photos, but they are approx. 40mm long x 15mm wide x 1mm thick. Half way along they are angled at 135deg and in each angled portion are the remains of a yellow plastic screw offset from the centre. They also had attached a thin transparent film with two holes on the lugs, but only one is present.
I searched high and low for some evidence of where they could have been fitted without success, and am now worried that they might be a vital part that would cause the machine to fail again.
Anyone any ideas of where I should put them, other than the laugh and tear up tray?