hi guys....i need to replace the transformer in my sharp gf 990 keyboard box.....i think someone has plugged 230 volts into the 110/120 volt slot....the box works on a 15 volt supply so must be the tranny as it is now open circuit.....i do have access to a lot of new ones but im unsure what rating it should be in amps , VA etc.....i.e. would a 15volt 6va do the job.........

what i do know is the gf is rated as follows:-

15 vold dc input
50 watt power consumption
2 amp glass fuse on the tranny pcb board

any ideas appreciated

Dave. The PS most certainly could have blown but we don't know that for sure since if the transformer blows, it usually will not blow instantaenously. Instead, it will supply the over-power condition for a period of time first, unless it is fused. If so, replacing the fuse should repair it. The second thing is that before the actual transformer blows, the rectifier diodes in the Power supply would likely blow next. That is not a particularly difficult repair to effect.

Both of these items should be checked before going any further. Transformers themselves are very durable items and downstream parts usually will destruct before the transformer does. If you think the PS might've blown but can confirm that the transformer itself is still OK, then the PS can be rebuilt. Find someone local or ship to someone else to rebuild it for you.

But in case the transformer actually is bad, just keep in mind that VA is another way of expressing watts. So they are the same. If your GF requires 50watts power consumption, you will need a 50va PS. Minimum.

How about posting a hi-res pic of your PS board.