Multimeter fault and doubt

Thread Starter

sepiyan

Joined Jan 13, 2011
4
Hi friends..!
I am siva.G from south india,
I am newbie for electronics,
so i was brought a multimeter for experiment purposes, the problem occured when i tried to test a tubelight ballast with multimeter, that time small spark appeared, hence it read something automatically like a mad do, also continuous beeps sound then I uncovered meter and tried to change fuse but there is no fuse..! however they pressed "fuse 500mA/250V" behind a parallel line. PLEASE HELP ME TO SOLVE THIS PROBLEM.
 

tom66

Joined May 9, 2009
2,595
I expect Somebody help
First of all, this is a free service. So people help out only if they feel the need to, or are able to. Wait more than 2 hours between posts.

Can you take a picture of the PCB of the multimeter? It seems likely that the fuse did blow.
 

marshallf3

Joined Jul 26, 2010
2,358
I hate to tell you but most fluorescent light ballasts will maintain a charge for long after they've failed, you may have kicked 400V DC back into your meter. There's really no way to test these, if you replace the tubes and you still don't have light then you need to replace the ballast.

When replacing a ballast, after unhooking it always short the two input terminals to each other then both to ground before even thinking about removing it.

These things usually operate by converting the incoming AC to DC then a simple oscillator circuit is used to step up the voltage and regulate the current. There are a number of designs.
 
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