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Old 01-13-2022, 04:44 PM   #1
shelby5041
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Default LCD tv power supply transformer magnets broke off

Hi

I have a typical lcd tv poeer supply
I dropped the board snd the magnets on the dc transformer broke off

Is the board no good now?

What is purpose of the magnets mounted on both sides of transformer
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Old 01-13-2022, 06:39 PM   #2
R_J
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Default Re: LCD tv power supply transformer magnets broke off

There are no "magnets" on a transformer, I think you are referring to the transformers ferrite core. Why not post a picture?
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Old 01-13-2022, 07:35 PM   #3
shelby5041
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Default Re: LCD tv power supply transformer magnets broke off

Thanks

Cant tske a pic

Here is stock photo
Pieces in yellow broke off

Will ps not operate now?
Attached Images
File Type: png 2022-01-13 20.33.10.png (1.12 MB, 28 views)
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Old 01-13-2022, 09:01 PM   #4
R_J
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Default Re: LCD tv power supply transformer magnets broke off

The power supply will likely still operate, but the transformer will not operate efficiently as the core is broken and its drive circuit will likely fail when the supply is under load.
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Old 01-14-2022, 06:01 AM   #5
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Default Re: LCD tv power supply transformer magnets broke off

Thanks
Is there anything i can do with the broken pieces to fix it or no

I guess ill put it back in tv and see what happens.
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Old 01-14-2022, 11:02 AM   #6
R_J
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Default Re: LCD tv power supply transformer magnets broke off

You can try fitting the pieces back but they would not be magnetically conductive like when they were originally. If used like that I suspect the transformer could run hot as well. It would be best to replace it if you can find one from another board, maybe one that the board is beyond economical repair but the transformer is good.
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Old 01-14-2022, 12:17 PM   #7
shelby5041
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Default Re: LCD tv power supply transformer magnets broke off

thank you
this is not worth repairing as it is just a tv i found in trash

i dont put money into tvs anynmore..not worth it

lcd tvs are worthless nowadays

ill just glue it together and see if tv powers on..if it does ill just leave it as is

if it no power on ill just toss tv in trash
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Old 01-14-2022, 03:28 PM   #8
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Default Re: LCD tv power supply transformer magnets broke off

hi JR

i glued the ferrite back in place as best i czn with super glue

i did test the ps outside of tv i do get 5v standby so i assume tv ps will porb work but as you said for how long

i really dont care for how long since the tv is just a project tv..i dont use it

so tomorrow i will install it in the tv and see what happens
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Old 01-21-2022, 03:00 AM   #9
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Default Re: LCD tv power supply transformer magnets broke off

Keep us posted what happens.
The glued core should work, so long as you didn't increase the gaps too much.
If it works, also put some silicone glue to hold the core together. Superglue does not deal that well with heat-cycling and may eventually crack. So to prevent the core from cracking, silicone glue is recommended to hold everything as a "backup".
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Old 01-21-2022, 07:09 AM   #10
shelby5041
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Default Re: LCD tv power supply transformer magnets broke off

Hi...i did superglue it and tv powered on fine as i expected

The unknown is how will it affect long term use...i dont usecthectv so ill never know

When you say silicone what area are you referring to?

Can i just incase the entire ferrite perimeter in silicone? And is it just 100% pure siliccone caulking or a silicone based heat resistant glue?
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Old 01-29-2022, 05:07 PM   #11
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Default Re: LCD tv power supply transformer magnets broke off

Awesome, good to hear you got it working!

Quote:
Originally Posted by shelby5041 View Post
When you say silicone what area are you referring to?

Can i just incase the entire ferrite perimeter in silicone? And is it just 100% pure siliccone caulking or a silicone based heat resistant glue?
Well, RTV / heat-resistant silicone would be better, but it's not necessary.
I've used regular cheap silicone caulking (they type used in bathrooms) with pretty good results so far. Only thing to watch out for is to make sure to get one that is low VOC / low odor. As silicone cures, it may release acetic acid, which can sometimes corrode electrical contacts and metals. The low VOC / low odor stuff, IIRC, releases a little less of that so it's overall safer for electronics.
I don't suggest encasing the entire transformer / ferrite with silicone, as that may reduce its cooling ability. But adding a good layer over the areas where the cracks were should work fine.

Last edited by momaka; 01-29-2022 at 05:09 PM..
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Old 01-29-2022, 05:54 PM   #12
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Default Re: LCD tv power supply transformer magnets broke off

Look for it indicating neutral cure for a non acetic acid version.
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Old 01-30-2022, 04:00 AM   #13
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Default Re: LCD tv power supply transformer magnets broke off

Thanks for the good info but
Its just a cheap lcd tv
Ill just use 100% silicone caulking i have on hand..

If it was something expensive or something i was going to keep long term i would use more appropriate silicone but its just a typical modern day crappy made lcd tv so

Thank you
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