How to test this transformer?

Question

Hi, I need help testing an inverter board transformer, I don't have much experience with this type of transformer and I'm not sure how to test it, I will be forever grateful for any suggestions.

the part is: TM-09175

photo attached.

Thanks

Seb

jw0752 · Accepted Answer

Hi Sebastian, I can see in your picture that there is an indication of wire and blue potting material in the wire channels on the two upper sets of contacts. I would expect to see some continuity between there connections at the top of your picture. It is unusual for transformers like this to fail. It would be even more unusual for the two side coils to both fail. Make sure you check all the combinations of the 4 upper connectors to see if they have made the connections in a less than obvious manner. If the upper connectors are indeed open then you have a failed component. John

clem57 · Answer

Looking at https://www.badcaps.net/forum/showthread.php?t=54410 , a few entries in has testing process for this inverter:

I would recap the board.
You can also have worn out lamp so it draws too much current as caused one of the two high Voltage windings to burn out.

__________________
Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956

Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999

Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl

Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/

TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809

dougw · Answer

Do you suspect the transformer is damaged? I don't know anything about this type of transformer so the following is just general transformer testing... First thing to do is a close visual inspection to see if all the windings and insulation are intact without nicks, pitting, dents or shorts and no signs of overheat (charring & discoloration). Next measure resistance between the 2 coils - I don't think they should be shorted together. Next measure the resistance of each coil - they should be very low resistance - not open circuit. You can try measuring the inductance of each coil to get some idea of the number of turns. You could try applying a low-voltage, current-limited oscillation signal to the primary (the coil with fewer turns and heavier wire) and see if the secondary has the appropriate step up voltage. If it is operating in its normal circuit, you can measure its temperature.

jw0752 · Answer

Yes that sounds normal. John

sebnast · Answer

Hi, thanks for all the answers guys, you're right I've had another look and both coils (thin wire) have around 1K between the pins the middle coil (multicore spun wire) has continuity between the pins. Is that expected behaviour please? Seb

sebnast · Answer

One of the possibilities yes as for the test the two pins attached to the braided wire are shorted and the rest has no relation to any other, it's all open line. (see photo)

dougw · Answer

I can't tell from the picture, but is there actually any wire in the cores at either end? It looks like there are channels for wire to come to the pins, but there is no wire coming to the pins... It looks like all the turns of braided wire are touching, which would mean there is no coil. Is this the case, or are all the strands coated with enamel?

How to test this transformer?

Top Replies