LaCie Hard Drive Power Supply Fault - Clicking Hard Drive

Symptom: Power supply lights up but the Hard Drive continually clicks and can not be accessed by the computer.

Cause: Faulty capacitors inside the PSU reduce its power output.

Cure: Replace capacitors.

Difficulty: Relatively easy if you can solder.

Note: Leave for ONE DAY after unplugging before you work on the unit because the main capacitor might hold a high voltage charge for a while.

Buy suitable Low ESR capacitors here:
http://www.satcure.co.uk/accs/low_ESR_capacitors.htm
Type CP100016HTF recommended.

This PSU is expensive to replace because it uses a miniature DIN plug - so you can't simply buy a generic one with a DC plug. This PSU supplies 12 volts and 5 volts on separate wires.

With a small hacksaw or sharp cutters, cut a groove at the two corners nearest the mains cable.

Use a flat-blade screwdriver to pry the two plastic shells apart.

The plastic shells are glued together all the way round so you might need to slide the screwdriver round the perimeter and apply quite a lot of force.

Be careful NOT to push the screwdriver blade inside because you could damage components. It's a good idea to slide a plastic tube up the blade so that only 5mm of flat blade is left exposed. You'll need quite a wide blade (at least 5mm) in order to apply a twisting force.

With a sharp blade, slice the rubber glue that holds the capacitors. Be careful not to damage the adjacent coil inductor.

Note the location of the two capacitors and apply fresh solder to their wires beneath the Printed Circuit Board (PCB).

Use desoldering braid to soak away the solder from each of the four wires.

Remove the capacitors from the PCB. You might need to reheat the wires if you can't easily pull them out.

Note that the tops of the capacitors are not perfectly flat. That tiny bulge indicates pressure inside, caused by overheating. (The capacitors were not the correct Low-ESR type.)

Fit the replacement (Low ESR) capacitors. Press them down onto the PCB and bend their wires slightly to hold them in position.

Apply solder then cut off the wires with sharp side-cutters.

The new replacement Low ESR capacitors are 1000uF 16 volt 105°C. (The same as the old ones but LOW ESR type so they should last for several years.)

Clamp or tape the two halves of the cover together and apply glue. I used hot-melt adhesive. You could simply use tape but bear in mind that the PSU runs warm. You could also use cable-ties.

Whatever you use, make sure that it's impossible to pull the cover shells apart because there are LIVE WIRES inside when it's plugged in.

SAFETY

Someone commented that it might be possible for the plastic shells to come apart. My experience of hot-melt adhesive is that it's not easy to pull apart but, if you are determined and stomp on the PSU, you might just manage it. If you are doubtful, please add very large cable ties. You could also use tape but don't overlay it excessively because the PSU needs to get rid of heat.

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