Hisense 65a7300ftuk - RSAG7.820.9659 schematics?

[retrorepair2]

I'm struggling with the above 65" TV, to be honest I'm not super familiar with TV repairs in general but the power board does seem to be giving me 12v and 19v (actually fluctuates between 18-20v).

Symptom is red standyby LED comes on, pressing power it will blink once, the second blink is brief where protect kicks in and goes back to steady red standby light.

The backlight did very briefly flash on a couple of attempts while probing voltages, I definitely wasn't shorting anything and it doesn't seem like slightly flexing the mainboard makes any difference.

I've also not got any voltage at all on the LED output on either left string or right string (assume that's what LP, LN and RP, RN means on XP6). Surely there should be something there when it's trying to power on?

Attached are images of the boards but feel like without schematics I'm going to have a hard time diagnosing this.

Is there any way I can test the LED strings? L and R both measure 5.7ohm across P and N with the leds connected, about 43k without.

[retrorepair2]

Re: Hisense 65a7300ftuk - RSAG7.820.9659 schematics?

I did notice L28 which seems to feed the IC above it (CS602) is 7.5v across the inductor when it's trying to boot, is this normal?

[retrorepair2]

Re: Hisense 65a7300ftuk - RSAG7.820.9659 schematics?

Well I was completely wrong, I was testing the speaker output. Idiot.

The LED output is on the PSU and when the standby button is pressed, jumps to 230v then stays steady until the rest of the system goes back into standby.

This seems to suggest from what I've seen, the LEDs may not in fact be the issue then? Is the a signal to turn the backlight on via the data cables to the display? It's really odd that it'll once in like 50 trys flicker the backlight a bit too.

[retrorepair2]

Re: Hisense 65a7300ftuk - RSAG7.820.9659 schematics?

Last note, I found the screen is coming on shining a light on it. I see the Hisense logo for about a second until it goes back to standby. Guess that's looking more like a bad LED then?

The LED connector coming from the panel looks completely open, should there be a resistance on there? Is there a way to test these LEDs without taking the whole thing apart?

[tech9pc]

Re: Hisense 65a7300ftuk - RSAG7.820.9659 schematics?

Don't overthink it. If you did the flashlight test and can see an image. It is bad led(s). I have fixed about 6 of these recently from 58" to 65" sharp / hisense. They are sold with backlights blaring at 100% and average user does not know that you can reduce them to extend the LED life. I set them to around 60 and picture is still bright. Been using one in bedroom for over a year now no problems. Here is a link to Aliexpress.com. Same leds you'll pay 100 bucks for in north america which orders them all from overseas cause we don't make them ourselves. only 27.00 shipped by PMALL. I have ordered from them several times. https://www.aliexpress.com/item/1005...d=SrpxOT6bbwD1
Good luck and happy fixin! Get R Done! lol

[retrorepair2]

Re: Hisense 65a7300ftuk - RSAG7.820.9659 schematics?

Thanks, yeah assumed as much.

It's someone else's problem now anyway, I didn't have the space to do it properly.

[tech9pc]

Re: Hisense 65a7300ftuk - RSAG7.820.9659 schematics?

Ya sorry to hear that. I am in little cottage not much room either. Somehow manage with my little kitchen / living room island lol