Thorn 65thl4kst1

[viewerau]

My friend has this television.

It stopped working, but still has power, but no image or sound.

It was under warranty, and instead of fixing it, the company sent him a new one.

The repair agent whom inspected the television reported that the fault was the main motherboards.

My friend would like to buy the parts and get his old one working as well.

I have looked online for spares, but note that this panel contains 2 x motherboards.

One is a B.RK3288.3 LC550EGE-DHM4 and the other part of it is 20F2 Main Board - T.MS3458.U801

Some pictures attached.

Each part is AU$93 each.

Is there any simple way to know which board is faulty, or is it a case of eenie meenie miny moe.

[nomoresonys]

Re: Thorn 65thl4kst1

The little one is your wifi board, the other is the mainboard.

[viewerau]

Re: Thorn 65thl4kst1

Thanks...that seems a big wifi board, but so be it.

Looks to me I may be best buying the one on the left with the rf/tuner, and hope for the best....

[nomoresonys]

Re: Thorn 65thl4kst1

Could do some voltage testing if you want to try to narrow the issue, start there:

Test the voltages at the connector on the powerboard with EVERYTHING hooked up, it's the connector that the cable from powerboard to mainboard hooks into, most times there's a legend/map nearby that gives the expected voltages, you measure them with your mutimeter, set meter to 20 vdc then report them, put neg probe on chassis metal ground, pos probe on pin of connector, measure in standby take note, leave probes where they are then power on tv and again take note of voltages, report them here, example pin 1-ps-on-0 volts standby-power on-3.3 volts.

[viewerau]

Re: Thorn 65thl4kst1

Many thanks nomoresonys...
I hope to have the tv dropped to me in the next few days for me to open it up.

I have noted today, during googling, that the left hand mainboard seems common to a number of different tv's on the market. One seemed to be JVC, Sceptre, and a couple of others, Bauhn too, I think?

Thank you.

[dick_barton]

Re: Thorn 65thl4kst1

They both appear to be mainboards. The only way to be certain is to open up the set and identify the correct mainboard for the LCD panel in the set

In post #1 the LC550EGE-DHM4 I believe is the LCD panel number it is paired with.

[viewerau]

Re: Thorn 65thl4kst1

Thanks dick...I think the actual number is LC650EGE-DHM8...which is different to the described part???

Googling those, I also found this link, indicating an LG telly???
https://www.panelook.com/LC650EGE-DH...iew_29029.html

[viewerau]

Re: Thorn 65thl4kst1

These were where I got the original photos
https://www.ebay.com.au/itm/313240251503
https://www.ebay.com.au/itm/313240273336

Naturally, I know taking the back off the telly will reveal correct numbers for me...cheers

[Diah]

Re: Thorn 65thl4kst1

dont be hurry LOL. if this was yours boards search this forum, before one year one user from Philippines posted dead JVC and it was the fault just one regulator under the main IC heat sink

[nomoresonys]

Re: Thorn 65thl4kst1

I thought it was an odd looking wifi board too but there it is evidently: https://www.ebay.ca/itm/254905757045...kAAOSww3FfYde2

[viewerau]

Re: Thorn 65thl4kst1

Hi...still awaiting this tv to look at.

I was searching for parts online, and noticed this:

This first photo is from a JVC T.MS3458.U801 Main-Board for U65CV-UMR ATVU65-0916 RTU6549-C 65UGX35 at a price of AU $53.99
https://www.ebay.com.au/itm/264935935927

The second photo is from a GENUINE THORN 65THL4KST1 20F2 Main Board - T.MS3458.U801 at a price of AU $90.35
https://www.ebay.com.au/itm/313240251503

Naturally the JVC board is the cheaper, but are the two mainboards the same, or could there be something on the main chip that makes each one either suit JVC only or Thorn only.

Could I be making a big mistake in buying the cheaper JVC one, rather than the more expensive genuine Thorn one, which is for a THorn TV?

Thank you.

[dick_barton]

Re: Thorn 65thl4kst1

The difference may be the LCD panel the mainboard is matched with.

[viewerau]

Re: Thorn 65thl4kst1

Thank Dick...does that sort of mean that one board will behave different to the other, when viewing the tv screen? Some functions may work differently?

Sorry...

[viewerau]

Re: Thorn 65thl4kst1

deleted

[viewerau]

Re: Thorn 65thl4kst1

Ahhh...my bad luck...I put another motherboard in, but all remains the same.

TV powers to on, but the screen is just white...grrrr

On inspection of these boards, I also note that the T-Con board also has texta letters on it....would this indicate that this may have also been replaced at some time?

Thanks

[viewerau]

Re: Thorn 65thl4kst1

I have been advised, via a youtube search on ShopJimmy (https://www.youtube.com/watch?v=yTnkOfwBGGE ) that a way to check that my t-con board has power, is to check power on an ic for power on the drain, gate and source to determine?

On picture number 2, can anyone identify the component to check please?

Thank you

[dick_barton]

Re: Thorn 65thl4kst1

"The screen is just white".....so the backlight is working.

Disconnect one cable from the tcon to the panel and see if you have half a picture then reconnect and repeat for the other cable.

[viewerau]

Re: Thorn 65thl4kst1

Thanks for your reply.

Do I have to power off the tv whilst removing and reinstalling the ribbon cables please?

Nearly 1:00 am in the morning now, so will look for a reply in the morning and try then

Thank you

[viewerau]

Re: Thorn 65thl4kst1

Sorry to be a pain again...

I just don't want to make things worse....do I need to power off the tv whilst removing and reconnecting these cables?

Thanks

[viewerau]

Re: Thorn 65thl4kst1

Ok...

I disconnected one tcon ribbon, and it all looked the same.

I then reconnected that ribbon, and removed the other.

This caused a change...one side illuminated bright white (left side) and the other side jet black.

Does this help with any diagnosis please?

Thank you.

EDIT...
I reseated all the cables, still no difference.

I could not work out how to open, remove this ribbon...is there a special way so I can ensure it is seated correctly?

Other picture shows with one ribbon connected.