Author Topic: [SOLVED] plugged wrong power supply in my preenfm2...  (Read 115 times)

chaocrator

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[SOLVED] plugged wrong power supply in my preenfm2...
« on: September 26, 2017, 02:27:32 PM »
so, today i've plugged wrong power supply in my preenfm2, for 2 or 3 seconds i think, and something bad happened.
a sticker on power supply says it's 9V 1A, but actually it outputs 12V.
after that, preenfm2 still turns on, the OLED comes all yellow, and that's all.
so, before my mate who built it for me can look at it, the question is: are there chances it survived and can be fixed?
« Last Edit: September 27, 2017, 05:07:02 PM by chaocrator »

Xavier

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Re: plugged wrong power supply in my preenfm2...
« Reply #1 on: September 26, 2017, 08:59:48 PM »
Many 9V power supplies have a higher voltage, specially when no current is provided (multimeter test).
2 or 3 seconds ? That should not be a problem. The 7805 voltage regulator must have turn hot, but that's all.

The OLED is yellow because the preenfm2 draws all the squares. Else it would be all black. So it kind of work.

You should verify the USB key.
The preenfm2 CPU seems to have problem reading it.

Xavier
« Last Edit: September 26, 2017, 09:01:29 PM by Xavier »

chaocrator

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Re: plugged wrong power supply in my preenfm2...
« Reply #2 on: September 27, 2017, 05:06:04 PM »
Many 9V power supplies have a higher voltage, specially when no current is provided (multimeter test).
2 or 3 seconds ? That should not be a problem. The 7805 voltage regulator must have turn hot, but that's all.

The OLED is yellow because the preenfm2 draws all the squares. Else it would be all black. So it kind of work.

You should verify the USB key.
The preenfm2 CPU seems to have problem reading it.

you designed this synth really smart way, i must say.

indeed, original USB key is dead. after i replaced it, everything's working again.

thanks a lot!