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Circuit blew - please help

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Mysonisapain

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My Son bought a US device off the internet , put UK plug on and blew the 2A board fuse !!!!!!!!!! He also blew what looked like a small blue capacitor, on what remains is ; K175 10 32 , I guessed that the 10 is microfarads and the 32 the volts, but what i don't understand is on the reverse of the board between the terminals is the symbol -N- ( the - is connected to the N ) , anyone any ideas ????????????

Mark ( harassed father )
If in Uk , call me if you'd like. 01452 760625
 

BradtheRad

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N and the minus sign are used to identify the negative lead of the capacitor.

The board must have been briefly exposed to twice its normal operating voltage.

You can replace the capacitor if you wish. The device may work then. It would be a lucky break.

Be sure to take note where the negative lead goes as you clip or unsolder the capacitor.
 

Senthilkumar_rjpm

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Yes.. usually N is indicate Negative side of capactiors... asume in your condition also.. for better answeres please put photo of that component (Blew)
 

FvM

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Don't jump in conclusions about capacitors...

The blue part is most likely a 175 V varistor (175 V is an industry standard varistor voltage), which clarifies, that the device is intended for 120 V US mains only. So you need a transformer to operate it in Europe. The varistor is an overvoltage protection, you don't necessarily need it to operate the device.

Hopefully, no other parts besides the fuse and varistor are damaged.
 

Mysonisapain

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N and the minus sign are used to identify the negative lead of the capacitor.

The board must have been briefly exposed to twice its normal operating voltage.

You can replace the capacitor if you wish. The device may work then. It would be a lucky break.

Be sure to take note where the negative lead goes as you clip or unsolder the capacitor.

It's NOT a "minus" and "N" . Between the teminals on reverse of board is a N witch is in the middle with a line drawn to either terminal.
I did replace the blown component with a 10 mf 35v cap , connecting it to the negitive side of the board using the shorter of the two legs , which use to denote neg , admittedly that was a looooooong time ago !
Just need to find symbol meaning.
 

alexan_e

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What kind of power supply does your device have, is it plugged to the wall or the mains voltage enter the device with a simple cable?
Do you see a transformer, if so sometimes there is a small switch that can select 110 or 220v operation.
Also some devices have a pulse PSU which can work from 100v to 230v but this is obviously not your case, there should be a sticker somewhere with the input voltage that the psu can work with?
US has 120v/60Hz mains and UK 220v/50Hz.

Alex
 

Mysonisapain

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The markings on the component where K175 and below 10 32 also a mark which i think is a manufacturers of a triangle and 07. The componet was soldered in parallel with a resistor.
 

Mysonisapain

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The device was 120v only ! My son did'nt look , but now is powered by 120v and still blows 2A fuse, have only a multimeter and no scope so will try to see if andthing gone short-circuit later.

---------- Post added at 11:45 ---------- Previous post was at 11:42 ----------

That's the baby , makes sense too , just need to find the one i need. CHEERS ALL ! XXXXXXXXXXXXXXXXXXXXXXX
 

FvM

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The device was 120v only !
It has been said.
now is powered by 120v and still blows 2A fuse
I hope you remove the erroneously placed 10u capacitor before? As the device has most likely a switching power supply input, the input rectifier, capacitor and at worst case the switcher IC are popular candidates for additonal damaged components. You have a good chance to identify them with just a multimeter - if you understand the circuit.
 

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