Short on a psu LS1904006A

[markm6164]

I have found the reason the choke was blowing fuses. After carefully unwinding each coil i found a small blown area which has taken out about 6 or 7 coils on each coil and blown a hole in the plastic divider. The coils were not physically touching/shorted hense the reason i didn't read a short between the coils on the meter but i suspect when power is applied to the choke this allowed an arch to jump the gap creating a short circuit. Very intresting.

Now i wonder if its wise to remove the other filter choke in the circuit and rewind that one? Even though its measures fine now maybe a month down the line that one will follow suit?

Also any advice what i could fill the hole in the coil divider/centre section with? Can you buy potting in small quantities?

 

[jackorocko]

Man you could have totally used my megger tester. If you had one, you could test the other coil and it would answer your question.

 

[markm6164]

Ok,, so what is it and how does it work??

 

[jackorocko]

it is a resistance tester that uses high voltages to test against insulation failures. In almost the exact same way as a MM works, except the megger will output +500VDC to break down weak insulation.

 

[markm6164]

Sounds good

 

[Rleo6965]

How about placing MOV to protect your power supply? I think the damaged choke was the first one. Place 1 MOV before the choke and another MOV after the choke. Next time your ps would not be lucky.

 

[Heylow]

I have the exact same problem with my power board (ls1904006a).
The fuse is blown and the area under the coil is blackened as well.
When I at first opened my TV and replaced the fuse, smoke came out of the coil and the fuse blew again.

I have been trying to find a replacement for the coil (LCL-1608WH), but the label does not seem to be a name and I have no idea the value it has.
I have few old Computer monitors and PSU's, but have been unable to find anything.

Any idea's on how I can obtain a replacement?
Otherwise only other option is replacing the entire power board, which I found for cheap prices.

 

[Rleo6965]

If the coil was a ac line filter choke. You can use psu and monitor ac line filter choke as long that winding coil was not smaller the original choke.

I have encountered a carbonized filter choke. I just removed the the defective winding and rewind it again with same size of copper and turns.

 

[Heylow]

As mentioned in my post, none of the devices I have the coil/ac line filter choke of this size particular size.

I have been scouring Google for the power board of this TV (found shops but only for US and I am in UK)
or any other for that matter to find it.
But finding a replacement for the coil itself, rather than the entire board would be preferred.

If anyone could help me find the coil itself or knows on what other devices to find it on?