General question about circuit design (power supply board)

[ryanfan03]

so I have 2 different tvs that each have a flaw on the power supply. Each keeps blowing it's fuse. The one I quick tested some components and noticed a transistor that could be faulty. Pulled it but it was ok. Out of curiosity I put my probes on the pads that the transistor sits on and two of them tested positive for continuity.

The other power supply was similar with a diode. It tested fine out of circuit but the pads them selves were continuous.

So my question is do the positive tests for continuity on the pads of the circuit board cause the fuse to blow and if so is there a way to fix the problem.

Thanks and sorry if this is the wrong section of the forum.

[tom66]

Re: General question about circuit design (power supply board)

Fuses only blow suddenly if there is a path for a large amount of current, so if the pads are connected in such a way that the fuse will conduct a large amount of current, for example one end of the fuse is connected to B+ and one to ground, it will pop.

[Agent24]

Re: General question about circuit design (power supply board)

noticed a transistor that could be faulty. Pulled it but it was ok. Out of curiosity I put my probes on the pads that the transistor sits on and two of them tested positive for continuity.

The other power supply was similar with a diode. It tested fine out of circuit but the pads them selves were continuous.

It can be a sign that a part in parallel with the part you removed may be shorted.