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Hi,

I purchased a second hand ART digital MPA preamp a few yrs ago from the USA and had it shipped to Ireland. The unit was rated 110v and I sucessfully used a volage converter to comply with the 220v standard here in Ireland. However, last week i stupidly plugged the wrong kettle lead (location recording) into the back of the unit and switched it on, the lights flickered and she went dead, not a peek out of it.

What is the most lightly component that i have blown and with my limited knowlodge of diy audio (soldering), is it realistic that i can do the repairs myself...Is it very difficult to convert the unit to 220 volts?

If u need to c photos of the inside of the unit i can do this tomorrow and post them here and i haven't been able to find any schematics for this unit

thanks and regards
hally

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hally Mon, 07/18/2011 - 14:50

bouldersound, post: 374196 wrote: Most likely you burned some windings on the power supply transformer's primary. Replacing the transformer with one for 240V may fix the unit and make it compatible with your power if no other parts were damaged. I would contact ART before getting into it.

Thanks [[url=http://[/URL]="http://recording.or…"]bouldersound[/]="http://recording.or…"]bouldersound[/],
I contacted ART already and they were not very helpful, my unit is out of warrenty and i bought it 2nd hand so they said there wasn't anything they cud do...

How should i proceed, there is a local tecky guy who fixes gear but charges outragous amounts for what he calls a "specialised service" (which it is) but i he's just greedy, can i try and fix this myself?

regards
hally

Boswell Tue, 07/19/2011 - 09:47

Serious question: does it smell? If not, it's possible you have simply blown a fuse. The plastic cover at the lower section of the mains inlet has a protective fuse behind it. Prize open the cover and check the fuse. If blown, replace with exactly the same type, and try again, powered with 120V this time.

Good luck.

RemyRAD Sat, 07/23/2011 - 06:01

All these devices have some kind of internal fusing. They are not always accessible from the back of the chassis as is many other pieces of professional equipment. There is no real reason why the power transformer would blow. It is more likely that the bridge rectifier blew. Transformers really don't care what comes in or goes out. They only care about load. Rectifiers that convert the AC to DC are active circuit devices with maximum voltage ratings specified. Generally they open interrupting the circuit. However some situations may cause a short. That short could blow the transformer. However, not being ultra-familiar with that particular unit, it may utilize a computer style switching power supply. Generally, you don't repair those, you replace those. If it's on the main circuit board, you may be screwed? If it's an ancillary circuit board, you may be able to order a new one? Either way, you should pick up a couple of DIY electronics magazines to have a slightly better understanding that may help your insights into this what could be a simple repair.

Hard knocks are tough
Mx. Remy Ann David