Yamaha REV 1 with a broken psu

[NoisyIndividual]

There's a third board, PWB3.
this takes the voltages from PWB2 and actually runs PWB1.


However, for some reason I think yours failed due to excessive mains voltage input, though I can't now find the post here that says that.


The one I had was a Japanese 100v unit that was subjected to 240v.

This fried the main switching transistors and nothing else.

So maybe yours is the same, and the design of the SMPS has this in mind, and will gracefully fail accordingly.

I wouldn't put it past Yamaha to have done that.

 

[dreamix]

There's a third board, PWB3.
this takes the voltages from PWB2 and actually runs PWB1.


However, for some reason I think yours failed due to excessive mains voltage input, though I can't now find the post here that says that.


The one I had was a Japanese 100v unit that was subjected to 240v.

This fried the main switching transistors and nothing else.

So maybe yours is the same, and the design of the SMPS has this in mind, and will gracefully fail accordingly.

I wouldn't put it past Yamaha to have done that.

Thanks again for your input!
That makes sense, I will put the power supply all together and try run it with a 60W lightbulb I found.

Yes this unit is 120v , 150W ...but got hit with 240v

Im no expert, I can only do some simple measurments, replace some stuff and see if it runs ...to me it seems only the power transistors and the 6.8 ohm wire wound resistor went.
I have managed pretty good so far through the years but wouldnt have managed without forums, youtube, and great help from people like you so... much appreciated!

Edit: All works fine now

 

[NoisyIndividual]

Xlnt.
I think Yamaha did a good job on that PSU.