Bad, bad caps.

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I was given a broken Acer monitor recently which was powering up but not displaying anything. I took it apart and was surprised to find this, but not where I expected it.


The capacitors in the main power supply were fine and the supply was giving out the correct voltages, but for some reason Acer (or whoever made the power board) had decided to use a different manufacturer's capacitors for the part of the circuit powering the backlight inverter and 3 of these had blown. You can clearly see the top of the capacitor has been pushed up and evidence of leaking electrolyte in the 'hot-cross bun'.


This looked like an ideal candidate to test my new capacitance meter I got on Amazon and received (from China of course) only last week. The capacitor is marked as 1000uF, so let's see what it is actually doing now.


Oh dear, only 230uF and probably on it's way to a dead short. Unfortunately one of the other ones looked like it had exploded and had shorted out which in turn had fried one of the 2 inverter ICs. Not worth repairing so I stripped the monitor for a few parts and the carcass has gone to the dump this afternoon.

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