yamaha psr

Very well could have blown all kinds of stuff. You'll need a service manual, and if you aren't a tech type yourself, best just get it to a shop.

Mark Z.

Given that the overvoltage was nearly four times the rated voltage, there's a good chance virtually "everything" in the unit is blown. By all means have a tech look at it, but I wouldn't be optimistic.

there's

have

And the fry factor by about the square , something approaching x16

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

l,

If i knew exactly where to check,i hoped i could find precisely what to replace-if its just a replaceable component that is..I have some theory behind me from some electronics modules ive done, but havent experience...thought if someone knew what and where to check resistance/power/caps or whatever it could be straight forward but as i said...ive no experience.. cant find a tech to look at it thats why gotta try sort it out myself... bummer...doesnt look hopeful does it..im looking for a service manual at the moment-might shed some light on the situation...kepp lookin... thanks M

ve

unfortunately I cant find a tech to have a look...im in the process of finding a service manual to hopefully troubleshoot and come across a protection unit or something like that..but "virtually everything" doesnt sound enticing!.. only got the thing at christmas,2nd hand with no dc input...should have checked before i plugged in that 45v mother.. gonna keep on lookin-

thanks for your time Will S

The OP's problem implicitly raises an interesting point.

We don't think of IC circuitry (as opposed to discrete) as drawing a lot of current. Nor do we think of it as being able to pull enough overcurrent for a long-enough period -- without being damaged -- to pop a fuse.

Most electronic equipment has a fuse on the line side of the power supply, and some has fuses on parts of the circuit that draw or pass a lot of current (eg, an output stage). But I don't remember seeing fuses directly protecting circuitry that's mostly LSI (or even SSI).

How often are fuses used in such circuitry?

of

for

How many nS/uS to knock out silicon before the mS to knock out fuse wire ? The fuse is just to give a bit of protection of reduced chance of consequential combustion.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on