Hi,
Finally it happened…My beloved P-250 died today…I cannot turn it on, I double checked fuses and connectors - everything looks good. Maybe there is something on fuses assembly (spiral part in small plastic square), power switch or something with MA60 power assembly board.
I need 240V (European)power transfomer for my P-250. Original part number is:
XQ431 (E) B0 DS 07M SMD 12
I attached a photo of this part.
Any information will be helpful. Thank You for attention!
best regards
Rafal
Hello.
Dear Rafal.
Does the transformer smell like burned?
Did you measured the output voltage?
Have you done something wrong with the input voltage?
I never heard about a burned tranformer! But who knows!
Best regards.
Hello,
No, probably transformer is ok, but Power Supply Board can be faulty. Strange thing is that every fuses are in good condition (!!!), so it looks like some of the condensers or power stabilization is dead.
Will check it, but I’m not a pro technician/service guy, I can repair my analogs on my own, but this baby is digital…
best regards
Rafal
So, it looks like the OMRON G5Z-2A relay is damaged - when I shake it delicately, there is something moving inside. I have found those relays here in Poland. I’m going to replace it soon, so I will tell You what is goin on. I hope it is only that small part…This part costs maybe 6$…
regards
Hi Everyone,
It is a shame for me to write about it, but. it happens.from time to time…Finally I repaired my P-250 piano and it works 
Why it is a shame for me? Let’s explain…
On the Power Supply board there are three fuses - 3x T5AL 250V slow-blow fuses. I was checking three times those fuses, but only visually…So when I used gauge/electronic meter, I have found one bad/blown fuse…
What’s the moral of the story?
DON’ TRUST YOUR EYES, USE ELECTRONIC METER/GAUGE!
best regards
This is an older post, but I’m hoping someone can help me out.
I have verified that the PT isn’t working. I have the US model. I’ve verified there are no shorts. Fuses are all good. The winding with the two yellow wires is the issue. One leg is putting out 8Vac, the other is only putting out 0.8Vac, so when it comes to the full wave and bridge rectifier for the 3v3 and 5v regulators, they don’t get enough voltage to produce an output. That means none of the digital electronics will function.
Problem is, I can’t seem to find a replacement transformer, and of course, Yamaha no longer makes this or has it. So, my only option is to find a used one, or if someone can get me the voltages from a working unit, I can talk to a transformer manufacturer (I have a local company that will custom build with the right info) to have a replacement made up. The schematic doesn’t give me the voltages coming off the transformer, but I’m guessing the yellow winding should have 8v-8v and the R-B-R is 20V-0V-20V. Can anyone confirm this? The other models should produce the same outputs on their windings, so really, I just need to know what the output voltages are.
Original part number according to the service manual is XQ430C00.
