Hisense 43A7100FTUK 2/3 red blinks.

[Donny2derby]

Hi again all.

Have got this set and trying to trouble shoot the above issue. I'm not sure if it's giving 2 or 3 standby blinks as one of them appears to be a very quick double blink.

The screen remains dead at all time. My fault finding so far has led me to what I believe is the barrier diode marked MBR B102 00CT. Which has two opposing diodes marked on it. And my meter is reading a dead short both ways when connected onto the board.

The reason I'm thinking this could be at fault is that everything up to there on the hot side tests and measures ok. I'm also getting a fluctuating voltage of between 140-170vDC on the connector pins marked LP & LN which supply's a connector marked XB 1216790 which goes up round the back of the telly and could be for the backlight??

Pictures below.

[Donny2derby]

Re: Hisense 43A7100FTUK 2/3 red blinks.

Ok when the barrier diode is lifted from the board I get a diode junction on both diodes when my black lead is on the common cathode and red onto both anodes. So I’m comfortable that’s ok.

Can anyone point me to where I should be getting voltage? I can’t seem to locate a standby rail anywhere.

[Donny2derby]

Re: Hisense 43A7100FTUK 2/3 red blinks.

I also have 15v Dc stable across caps c957 and c958

[Donny2derby]

Re: Hisense 43A7100FTUK 2/3 red blinks.

Ok I’ve got the fluctuation voltage back at my backlight connector again. Or what I believe to be the backlight connector.

Am I in the right ball park here??

Where’s my guy Diah at? Talk to me goose

[Donny2derby]

Re: Hisense 43A7100FTUK 2/3 red blinks.

Ok so I've found terminal rail XP4. Is this where my standby 3v and 5v should be??

[Diah]

Re: Hisense 43A7100FTUK 2/3 red blinks.

Ok I’ve got the fluctuation voltage back at my backlight connector again. Or what I believe to be the backlight connector.

Am I in the right ball park here??

Where’s my guy Diah at? Talk to me goose

buy led tester to switch all ( as one group on ) and tell. V & A reading. or take the panel out and see if they get one less than 1 second on... if they are fine..
then we have other known issue at panel buffer boards or one SMD cap short on BL Section at MB all in one.

search this forum you will find similar threat

[Donny2derby]

Re: Hisense 43A7100FTUK 2/3 red blinks.

Thank you for your help as always Diah.

The reason I believe the issue is on the MB is that when the cable to panel backlight is disconnected I get the voltage fluctuation.

I have found one Cap which is 1uf 400v reading around 920 nano farad but is discharging when read with multimeter in capacitance test mode. This capacitor is very close to backlight cable connection.

I will buy one of these soon and see what happens.

I have looked at other Hisense threads as well Diah and they are of some help but I couldn’t find one with my exact issue.

I should add that I currently have the MB disconnected entirely from all other connectors. Backlight, lvds ribbon cables, speaker cable. And fluctuation of voltage still present on backlight connector.

[Diah]

Re: Hisense 43A7100FTUK 2/3 red blinks.

I should add that I currently have the MB disconnected entirely from all other connectors. Backlight, lvds ribbon cables, speaker cable. And fluctuation of voltage still present on backlight connector.

its all in one boards.... mean will be active always ... so it need loads... test the LEDs first if they are fine then working on issue..

[Donny2derby]

Re: Hisense 43A7100FTUK 2/3 red blinks.

Ok Diah sorry for delay in reply. Life sometimes get in the way.

I’m beginning work on this again now and will report back findings of LED’s.

[Donny2derby]

Re: Hisense 43A7100FTUK 2/3 red blinks.

Cracked it Diah!

One strip of LED’s has one diode out and giving fluctuating voltage on LED tester. Can i assume this is what the MB is detecting and not going through its power boot??

Will order and replace.

[EazyBone]

Re: Hisense 43A7100FTUK 2/3 red blinks.

LED short will cause problems with power boot on random tvs so definitely could be true for this one. I have experienced this. Fix that bad boy up and let us know

[Donny2derby]

Re: Hisense 43A7100FTUK 2/3 red blinks.

2 LED strips on their way on a slow boat from china Mr Bone. Will let you know how it goes when those mofos get Uk side.

[EazyBone]

Re: Hisense 43A7100FTUK 2/3 red blinks.

Yes I use ali express. Take usually 2 weeks

[Donny2derby]

Sorted! Installed the 2 new backlights and good as new! Easy money! Next project on the way!

[Donny2derby]

[EazyBone]

Good. Thanks for update