help with 32" LCD TV

[seanduk]

Hi Guys.
A relative of mine has a 32" TV which is giving her problems, & I'm trying to help. The TV works perfectly for around 30 mins - 1 Hour & then vertical multicolored lines appear all over the screen, while the sound still plays fine.

I had a look at the Power supply board, & noticed 3 680uf 35V capacitors, one of which looked slightly bulged at the top & when I desoldered them I noticed the same one was bulging at the bottom also.

The board itself also is stained where the 3 capacitors once were, I'm including HQ pics to show the caps in question & the board.

My question is; Do you guys think I'm on the right track? & also; do you notice anything else wrong with the board, going from the photos? I can provide pics of the rest of the TV if needed.

Thanks in advance guys.

Edit: Sorry for massive pics, will upload smaller ones

[tom66]

Re: help with 32" LCD TV

I have seen this problem before on the same PSU and probably the same TV. (Lexsor? Logik?)

It is accelerated by the caps but it is also caused by the 5V supply for the T-con on the main board malfunctioning. This is a buck converter IC and it appears to fail as it is run very hot. It may be possible to replace it but it could be simpler to use a separate DC-DC board as I did. I used one for a model aircraft rated at 5V, 3A.

[selldoor]

Re: help with 32" LCD TV

Welcome to the forum- Please update the mains voltage and country in your profile.
If you post more pictures please use the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.
(max resolution 2000x2000 and 2MB)
Some members will not wait for inline hi def pics to load and will move on to the next thread.

Please quote make and model number of tv (amend the thread title if poss) good pictures of the front and backs of your boards would be useful and helpful for others working on this set.

[seanduk]

Re: help with HARWA 32" LCD TV

Sorry about that selldoor, didn't realize the pics were so big. Hopefully all fixed now. Thank you as well Tom, for taking the time to reply, The TV is actually a Harwa, can't for the life of me find a model number though, front or back.

This is the 4th TV I've ever attempted to repair the other 3 were all repaired by replacing capacitors, was hoping this was going to be the same,

I have already ordered some replacement caps, is there any chance fitting these will give her a few more months use of the set to allow her to save for a new one? & if not could you please highlight the part i need to replace using the photos?

Thanks again for all replies & Sorry again for uploading massive pics

Sean.

[selldoor]

Re: help with 32" LCD TV

Pics are great -thanks - Cant see anything obviously wrong in those - you will need to try and clean off any leakage from the caps. Just for the record what brand are the orange ones.
One of the boards is numbered 782 l27w18 4000 which is an inputs board the same as in Lexor 27 and 32 inch

Power supply is kas200-5s241812XS and is also used in lexor and polaroid. Hah just seen Tom66 was looking for schematics for this on ESI last September -( suspected failed toroid) remember that one Tom?
If you post pics of the main board we will be able to point out the problem area mentioned by Tom.

[seanduk]

Re: help with 32" LCD TV

Thanks selldoor, The battery just ran out on my camera, so will have to give it an hour or so to charge.. as soon as it does, I'll update with more pics & the brand of the orange caps

Thanks again.

[tom66]

Re: help with 32" LCD TV

Hi you would need to take off the shield on the upper board to get to the DC-DC buck converter. It's on the righthand side. There are two of them. I think the lower one is the one that malfunctions.

Caps may help, at any rate they are needed anyway to make it last.

Selldoor I narrowed the fault down to the main board but the PSU developed another fault so it's sitting unused in the shed ready for parting out I suspect, not worth repairing anymore.

[seanduk]

Re: help with 32" LCD TV

OK, Thanks for bearing with me guys I'm back with the requested photo.
My board isn't labeled "782 L27W18 4000", but is instead "782 L37W25 6900"

& selldoor, the Orange caps say "JH" "CD263"

Thanks for the help guys.

[seanduk]

Re: help with 32" LCD TV

Another thing I should have mentioned guys; I Have 2 old TV's with smashed panels in my Garage, A Goodman's 20'' & Goodman's 32'' If I'm not mistaken, Any chance the part I'm looking for being in one of those?

[tom66]

Re: help with 32" LCD TV

The devices with 470 written on them... the bottom one... check the voltage on both ends. When the voltage disappears you know this is the fault. The AOxxxx chip probably needs replacement but I just disabled it and used this: http://www.ebay.co.uk/itm/RC-3A-U-BE...item2560c9ea36

[seanduk]

Re: help with 32" LCD TV

Thanks a bunch mate, will update the thread with the outcome when the replacement caps come in & I have another go at it

[keithdisco]

Re: help with 32" LCD TV

let us know how you get on

i have the 37" model that just failed with color lines going down the screen
ive narrowed it down to the dcre chip on that signal board when heated it works ok when it cools the problem reapears

[Winny]

Re: help with 32" LCD TV

Hi I have Hanwa 32 inch lcd, being honest I am a novice when it comes to repairing tvs. I wish I would have found this forum before I tried to resolder connections on the lower board with the eight connectors. I started off with multicoloured vertical lines and now I get no picture at all!! If I had known to replace the caps I would have tried this firtst, not wanting to sound dumb but were can I order parts from such as caps for this hanwa 32inch lcd tv????

[ashok]

Re: help with 32" LCD TV

Hi Tom,

Do you know where the buck converter IC is located please and also do you know the chip number or the component number on the board please?

Thanks

[ashok]

Re: help with 32" LCD TV

by the guys
its a lexsor 32in tv and when i try to power it up there is no power at all. i have checked all the caps and they seem to be ok, no leaking or bulging. any suggestions please?

Thanks

[ashok]

Re: help with 32" LCD TV

just found them two IC's, i'll get the datasheet and check the output tomorrow. Should the output be 5V constant or doest it change? i.e. pwm, clock pulse etc?