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Christian Treldal Christian Treldal is offline
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Default Roland keyboard power supply problem

Den Thu, 25 Jan 2007 09:54:35 +0000 skrev Mungo \"Two Sheds\" Toadfoot:


One other possible symptom is that the main transformer on the power board
hisses. The sound changes if I push on the transformer itself, or on the
board. There are two large capacitors near the transformer, one of which has
a small bulge on the top, which can be pushed back down easily, but shows no
sign of leaking, nor do any of the other caps.

Any thoughts?


New capacitors. The bulge is a sign. If you mesure them with aa ESR meter
you will find a high esr. It cauces all kinds of strange faults in the PSU.

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Vy73 de OZ1GNN