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PostPosted: Fri May 09, 2008 8:52 pm    Post subject: Re: Citizen C27401 TV blown fuse

barney wrote:
3 years old TV, 3.15A fuse keep blowing.

I took out the HOT, #C4460 (NTE2594), tested leaky. No short circuit without the HOT.

I'll try to find the hot today and change it.

Anything else to check ?

BTW great forum !

Thank you.


Check also the rectifier circuit.
torbjorn
PostPosted: Fri May 09, 2008 9:33 am    Post subject:

If the HOT is defective or suspect, always check out why it has failed.

For example: flyback capacitor, all components in series with the horizontal deflection coils, bad solder joints in the horizontal output area, bad connections to the deflection coils, problems with horizontal drive (either too weak drive pulse so that the HOT doesn't get completely saturated, or horizontal frequency way off from the correct value).

However, it sounds strange that a fuse should blow due to a defective HOT. In conventionally designed TVs, the power supply should begin current limiting, tripping, in such cases. If there is a simple, non-isolated power supply (series regulator or buck converter), make sure that it operates correctly. If the switching/regulator transistor of a such power supply gets shorted, the output voltage will be way too high and cause lots of damage in the set.
barney
PostPosted: Thu May 08, 2008 4:20 pm    Post subject: Citizen C27401 TV blown fuse

3 years old TV, 3.15A fuse keep blowing.

I took out the HOT, #C4460 (NTE2594), tested leaky. No short circuit without the HOT.

I'll try to find the hot today and change it.

Anything else to check ?

BTW great forum !

Thank you.

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