[cathoderay57]

Hi David, thanks for the additional tip. I will warn the recipient in case the problem recurs. The original fault was that on power-on the Apple on-light illuminated briefly, then extinguished. Hopefully it was just the dodgy cap that I have replaced but, if not, then at least I now have another option to explore. For anyone attempting a similar repair, it's maybe worthwhile if I add a few tips on dismantling. The cover is removed by first extracting 4 cross-headed screws. The short edge of the cover has locking tabs that slide into slots so the cover has to be slid sideways to release the tabs. Inside, the PCB is secured to the chassis by another 4 cross-headed screws. Three are simple to unscrew, but the fourth is partly concealed by a large rectangular filter capacitor soldered to the mains IEC connector terminals, and access to the nearby screw is made more difficult by a liberal blob of potting compound used to stick the capacitor to the PCB. Once the 4 screws are out, the filter capacitor and the blue and brown mains input leads need to be de-soldered from the IEC connector, and the earth lead unscrewed from the chassis. The locking clips on the IEC connector can then be pushed in temporarily with a screwdriver sufficiently to slide the connector out of the chassis hole. Then the 2 pairs of red and black leads from the fans need to be released from the coiled components on the PCB to which they are stuck with more potting compound. Once the wires are released the locking tabs on the fan plugs at the remote ends of the wires can be held open and the 2-pin plugs released. The cable tie around the fan wires and another tie restraining the large multi-coloured wiring harness to the chassis hole need to be snipped off. Then the PCB can be lifted clear of the chassis. One other thing to note - after removing power, the 3 x 100uF 450v electrolytics remain charged up to in excess of 150v for a long time and that's enough to give a painful shock - so worth checking and discharging them before handling the PCB. Some of the electrolytics are glued to the PCB with yet more potting compound but on mine it was still fairly pliable and easy to cut free with a sharp penknife. Cheers, Jerry