What happens if you connect 110 Volt 9090 receiver to the 220VAC

Kale

Super Member
And in case you are lucky!!!
First of all, transformer was OK, and the power stage was OK!!! Unbelievable !
But the main strike got a protection board:

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And what I replaced on that board:

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That is the same board, do you recognize it :) ?

On printed circuit side I had to fix that too:

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... with new piece of copper foil ....

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... and now that looks like on the next picture

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... complete board....

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BUT... that is not all... protection relay was looking like on the next picture (look second and third contact):

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... if you still don't see, look now:

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Plus 4 pieces of burned fuses, plus two resistors on Driver board.... and that is all!!!
Really not so bad, if you know that receiver was at 110 VAC position, and connected to the 220VAC
 
So, in summary, I think we can say that the protection board did it's job, and nearly lost it's life doing it - I bet there was a lot of smoke! :D (although not actually designed to protect against such mistakes).

Great Work!
 
So, in summary, I think we can say that the protection board did it's job, and nearly lost it's life doing it - I bet there was a lot of smoke! :D (although not actually designed to protect against such mistakes).

Great Work!
:) John, I totally agree with you... the protection board almost died on duty!
 
I'm working on some commercial amps that have a plug adapter. The actual cord end is European type and the adapter goes on that. They are of course set to 120 volts because this is the US.

I got a half a mind to change all the cords on them, I am thinking if one of them finds its way to England or something... POOF. I doubt they'll be willing to pay for that, changing all of them ? I think it MIGHT save us money in the long run as we are "the" factory service for these things.

Anyway, I had an international model of the 771 and switched it to 100 volts to squeeze a few more watts out of it. Lasted a long time, no fan even, and working into 2.3 ohms. (had to change the fuses)

Never blew an output, eventually something on the driver board went and it got retired. The
FM was broken anyway and it was used as an amp. Sounded pretty good actually. Nice, simple amp, no nine million transistors, basic straightforward design.

Anyway, some of these big amps, like the one in the 9090 actually act as their own surge suppressors. They can just barely handle the inrush when you turn them on, and you would have double that with 240 volts. However IIRC that one has an inrush limiter, which is what gave it time to blow anything. If not for that, I think the AC fuse would have blown immediately and nothing would have gotten hurt.

But on an amp like that, they would have to be forever replacing power switches and rectifier bridges. Either that or go with ridiculous rectifiers and maybe a knife switch for the power switch. I've seen/had amps that dimmed the lights alot when you turn them on.Not to the ppoint where you have to reset the clocks but...

If you got it running great. But there is alot of equipment out there that when fed with double the line voltage is fine' right now. Within 16.666 milliseconds, or 20 milliseconds where you got 50 Hz power.
 
Kale, I couldn't tell. You didn't say. In that case__me >>>:whip:<<< the other gentleman. Of course I'm just kidding around and congrats on a nice repair job.
~Dave~
 
If you got it working more power to you. My opinion with lightning strikes and mistaken 220-240 volt hookups... just throw the stuff away. Not worth it in the long run. They just keep breaking... and breaking.
 
If you got it working more power to you. My opinion with lightning strikes and mistaken 220-240 volt hookups... just throw the stuff away. Not worth it in the long run. They just keep breaking... and breaking.

Sounds like you have a story to share.:lurk:

Also, I think I see your point. In situations like this one, one does not know what other components have been effected or weakened besides the obviously blown ones.

Wouldn't a complete refurbishment be the best ultimate solution then?

Just "throwing away" a 9090 sounds a bit wasteful.
 
I agree. A partner hooked up a power distro wrong once, and sent 240 to a bunch of crown amps and crossovers. After about 3 months of continuous problem with that gear, we figured out just which ones had been in the "mistake" and threw them away.

That was business. We couldn't have systems going down on pro audio jobs.
 
Looks like it...

"Description 3M™ Tin-Plated Copper Foil Tape 1183 consists of a 1-ounce dead soft tin-plated copper foil backing and an electrically conductive, pressure-sensitive acrylic adhesive. This tape is supplied on a removable liner for easy handling and die-cutting. It has excellent solderability."

The amount of the stuff that Kale has there, it looks like he's expecting some 'heavy duty action' with tracklifters anonymous. :D
 
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