Any electronics gurus?

[Tom B]

10 year old 32" LG smart TV in the bedroom expired yesterday. It make a pop and went off.

Despite its age it's seen little use. Given it's age I immediately assumed it had popped a capacitor on the PSU.

I opened it up today and inspection shows the capacitors all look fine, however it appears the magic smoke has escaped from what looked to me like a small transformer.

This is coded 12S-LP02. Looking at a data sheet for the PSU module it suggests it is a transformer with another reference PQ3513 and a rating of 220uH which I read as MicroHenri.

Now I'd expect something with a rating MicroHenri to be an inductor.

Either-way I cannot find a replacement part or any trace of the component online.

Has anyone any offers of where I can source a replacement or alternative?

I haven't desoldered it yet, but hopefully there will be more ratings below.

Pictures below (not mine)

 

[presta]

It's probably a transformer but I can't see from that angle, and getting into overthinking it is not going to help much anyway. I doubt you'll find anywhere selling the transformers, you'll be looking for a new power supply.

There are several companies selling LG TV spares, but I can't identify your PCB without the TV model number, and 5 years is a typical period for spares availability, so yours might not be available now.

They're quite expensive, so before splashing out a lot of cash bear in mind that burnt bits might be victims rather than the culprit.

https://www.tvparts.co.uk/lcd-tv-spares/power-supply-lcd/lg-1
https://www.tvserviceparts.com/LG-TV-Power-Supply-Boards.html
https://www.spareslg.com/gb/tv-audio-e-video-tv-fonte-de-alimentacao
https://www.expresstvparts.co.uk/search?type=product&q=psu

 

[slowmotion]

It looks like a transformer to me with the primary connections on the left. The thin wire coil is on the left and the thick one on the right, i.e. the lower voltage side. The photo you posted comes from ksp-electronics.com.

Try sending them an email and pick their brains about it. Good luck.

BTW, if you can wield a soldering iron, you can replace it with anything that has the same spec. as the original if you are prepared to use some tyraps, heat shrink sleeving, and extension wires.

 

[Tom B]

Thanks guys.

Ive seen the online spares, you can get some used boards of unknown vintage for about £40+ which seems a lot when I can get a new half decent TV for a bit over £130, and when the same fault may emerge next month.

Ideally I'd like a like for like replacement part, but am more than happy to make a suitable component fit, despite mine being quite a low profile board there is plenty of room in the case. I recently changed the power supply caps in my mother's TV and one of the replacement caps needed relocation due to being a different shape.

My problem is, the part as it sits in the board has no ratings the data sheet seems erroneous in rating it in Henri... In my limited electronics experience I've never come Henri ratings for transformers. Unless anyone can advise different? I'm going to pop the part off the board later and see if there are any markings underneath and check a few other items to see if there is any collateral.

If I can get a part cheap enough it'll be worth changing it just to see if it can be saved.

Edit: I've popped off the component.... No further markings.

 

[cyberknight]

in a similar vein some one cleaned out the deep fat fryer and now its shorting the entire house

 

[CXRAndy]

10 year old 32" LG smart TV in the bedroom expired yesterday. It make a pop and went off.

Despite its age it's seen little use. Given it's age I immediately assumed it had popped a capacitor on the PSU.

I opened it up today and inspection shows the capacitors all look fine, however it appears the magic smoke has escaped from what looked to me like a small transformer.

This is coded 12S-LP02. Looking at a data sheet for the PSU module it suggests it is a transformer with another reference PQ3513 and a rating of 220uH which I read as MicroHenri.

Now I'd expect something with a rating MicroHenri to be an inductor.

Either-way I cannot find a replacement part or any trace of the component online.

Has anyone any offers of where I can source a replacement or alternative?

I haven't desoldered it yet, but hopefully there will be more ratings below.

Pictures below (not mine)
View attachment 679870

View attachment 679871

That looks like a basic mains transformer. Above it is an encapsulated bridge rectifier and below looks like a largish capacitor.

Transformers do and can fail usually by going open circuit on the primary winding. You could measure the resistance of the windings to help diagnose if it has failed. Also check the bridge rectifier hasn't got a short circuit diode.

The actual voltage will be a bit of guess work. However with a bit of circuit analysis you can workout the output voltage and purchase a replacement from Farnell/CPC or RS components.

 

[Mike_P]

A google search thrown up a LG data sheet, again does not seem to list the voltage of the transformer but printed out and studied a clue might exist somewhere under the following an address starting
adjuntos.yoreparo.com (link would not probably copy)

 

[Tom B]

So while googling around and looking at fleabay for other cards withe the same transformer to butcher. I found a chap flogging a used card for a tenner under a pot
description. I've checked the photo is the card he's selling and bit his hand off. He's away for 5days so can't send it till next weekend. So hopefully problem solved.

I pulled the transformer to bits.

6 turns of thin on the secondary and 50 turns of thick on the primary. (26-28v?) Only damage I could find was some burning right on the ends of the primary suggesting it's maybe flashed across them before cooking a fuse on the board.

 

[mad despot]

Keep us up to date with the outcome of your repair attempt!

 

[Tom B]

In the end I found the actual card listed on AliExpress (not fleabay as above) with a bad description and typo in the model number. It came from China in just under two weeks for a smidge over a tenner.

It was packaged in an antistatic bag in a perfectly sized box and appeared brand new.

Plugged it all in and it works just fine!

Next project (after a new heater in the mother's washing machine - I think dad is currently happy saving money the cold washes) and trying to find a new flat double sided motor for my cool box.

 

[Drago]

My tv view up. I had the TV moved from the servants quarters to my room and replaced it with a goldfish bowl.