Samsung TV`s UE32J5500AK and UE48H6400AK Red Standby Light - No Picture/Sound

[lotas]

First you need to make sure that the lighting is working. Some motherboards do not start when the backlight is not working.

[vinceroger69]

Programmers are cheap enough if your looking at repairing tvs as a hobby also worth buying is a led tester like whats in these links
https://www.ebay.co.uk/itm/203585702...3ABFBM8t_Xp8hj

https://www.ebay.co.uk/itm/364755536...3ABFBMzLLlp8hj

[slimsoul]

Thanks for all the help so far lotas & vinceroger69
UE48H6400AK update:
replaced the main board, now have power with backlights and sound but no picture?
(I can hear the led covers rattling around inside which I assume is what the bright spots are)

[lotas]

Check the fuse, is there 12v power on it, are the LEDs on the T-con lit?
White spots on the screen are the lenses falling off the LEDs, in the xxHxxxx series this is their disease.

[slimsoul]

Found the issue… I disconnected the t-con board connections when checking the connections were ok the last time I had the back off…. Didn’t connect the right one back fully. Tv now working👍🏽

[vinceroger69]

Found the issue… I disconnected the t-con board connections when checking the connections were ok the last time I had the back off…. Didn't connect the right one back fully. Tv now working👍🏽

Nice to hear a replacement mainboard fixed the issue the backlights still need changing these are the ones i purchashed for the set i repaired
LED backlight strip(12)for Samsung UE48H6400AK UE48H6470 UE48H6240 BN41-02176A UE48J6275 UE48H6200 UE48J6270 UE48H5000 ue48h5270 - AliExpress
Thermal Conductive Adhesive Double Sided Tape For LED CPU GPU Strip Chip IC 2023 | eBay

[slimsoul]

Thanks again, will order these. (Estimated shipping time is quoted as 67 days, I've not used AE before?)

[cheeky2]

You have different options of postage selection when ordering Aliexpress. The cheapest option is normally selected which is the longest to deliver. They will have options to select faster and more expensive shipping select the appropriate shipping delivery timescale.
Personally I wouldn't bother ordering from the seller vinceroger69 recommendation but use this seller https://www.aliexpress.com/item/1005006209602127.html? who's cheaper and quicker to delivery of April 7-11 if ordered today.
Look through carefully when ordering to ensure the same leds inside your TV are the ones you will be ordering! Why you may ask? Well more than one screen can be fitted to the same model of TV and different screens use different size leds and different amount of LED's inside the TV!
Though personally a quicker fix would be to get some adhesive to fix the existing led lenses back onto the leds. I tend to use the 5second ultra violet glue https://www.ebay.co.uk/itm/275912824273 which allows you to align the lens properly then use the uv light led to cure the glue when properly aligned.
Though this is assuming your leds haven't gone blue. If they have then you will need to replace them. Easiest way to check is to remove the cable connection to the TCON board and see if the leds are all white, if they are blue in any areas then replace all of them.

[vinceroger69]

Nice to hear a replacement mainboard fixed the issue the backlights still need changing these are the ones i purchashed for the set i repaired
LED backlight strip(12)for Samsung UE48H6400AK UE48H6470 UE48H6240 BN41-02176A UE48J6275 UE48H6200 UE48J6270 UE48H5000 ue48h5270 - AliExpress
Thermal Conductive Adhesive Double Sided Tape For LED CPU GPU Strip Chip IC 2023 | eBay

yes like cheeky2 rightly said there are different screens sometimes used in sets so the leds i ordered may not be the ones used in your set ( on the metal chassis of the tv should be a white sticker with the screen number on) most led strips i order from ali express arrive in around 15/20 days and that glue cheeky2 has recomended is really good i have used it on leds on lg tvs,

[slimsoul]

First you need to make sure that the lighting is working. Some motherboards do not start when the backlight is not working.

UE32J5500AK Update

Tested back lights and both strips light up fine. (Used 2 9v batteries with some wire on the + & - points on the strips)

Are there any checks i can do on the Power/Mainboard or other parts to narrow this down?

[lotas]

Well, I don't even know what to say, disconnect the WI-FI module, check without it, disconnect the panel, check the resistance and voltage on the DC/DC converters and SMD fuses on the board, check the resistance on the HDMI signal lines....

Or maybe the problem is in the firmware, but here you already need a programmer and knowledge.

[slimsoul]

Checked with my daughter what happened when the tv stopped working, the picture on the screen froze and sound glitched then the tv powered down? While watching YouTube… if that helps !

[vinceroger69]

Checked with my daughter what happened when the tv stopped working, the picture on the screen froze and sound glitched then the tv powered down? While watching YouTube… if that helps !

Reading online these sets do suffer from firmware issues
Regarding backlights i also like to see what amps each strip draws as if wrong could kick in error protection etc