L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

[IoT-Maker]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

@Davi.p thanks for your hint.

I never had a bad transformer on a PSU. Got this BN44-00627A here since March and could not fix it. First i found the D2011K damaged. The IC is next to the transformer. Also one UF4007G diode was damaged. I replaced it with a UF4007 only to find out weeks later it's causing trouble. The boost circuit was not working. It needs 390V but was only at around 316-320V. I replaced the UF4007 with the (hard to find) UF4007G which is much quicker and the boost voltage works.

But there was still a clicking and no stable output voltage. Because i could not find the fault, i bought a working board to compare measurements. Some values were different but not that much. At the end, i started to swap parts. I swapped all elkos, all diodes on the top side. Nothing helped.

Finally, because i read this post today and the transformer on the old board was heating up a little bit (which the one on the working board did not), i desoldered the 210064HD KE-03B DY transformer (something i did never before) and testet it with a DE-5000. One winding should have 0,410 Ohm but i read 1,230 Ohm. I swapped the transformer and the board was working as expected. No clicking, stable voltage.

[Donny2derby]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

What a way to end it!

I can’t believe you would stop! You’ve got 3 or 4 very knowledgeable and smart blokes basically spoon feeding you how to go about repairing the set and you’ve give up!

What a tit!

[Davi.p]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

Hi, in this and other series from same year it happened often to be failing transformer, you may have to re wrap it with good wire maybe took from another PS o or new

[cekanayake]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

Good morning or evening to everyone. I am abandoning this project as I don’t have the time to devote to it and my skills in this field have a lot to be desired. The last thing I checked was the optos and the diodes on the bottom side. I found 2 diodes short and replaced them and found the optos working when I pulled them and checked. This project is beyond my skill level. Thank you for all your help and support. I am willing to share anything from this project with any of you if you need anything please let me know and I will be happy to share them. Thank you all again for all your guidance.

[nomoresonys]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

Guess it could be an opto like you suggested earlier Diah, can maybe test them by freezing or heating, and see if the voltages are stable for a bit.

[Diah]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

i cant believe ICM801CS blown and just the fuse got open... there should be at the downside SMT parts went open too.

[nomoresonys]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

Check every diode on the powerboard, some may be on heatsinks, if you have a doubt about any of those caps and some available, just switch them out, otherwise you need to test them with a good cap checking meter out of circuit, you can not get a reliable accurate reading in circuit, if anyone don't believe it just check the pros on youtube with the 200 dollar cap meters, they say the same thing.

[cekanayake]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

yours PSU had not enough juice ../ weak . BTW you didn't write any things about pns Vamp 13V... so you need to work on the PSU include to measure all CAPs MSR

The Vamp pins 11 and 13 are at 8.04v
Caps cs801 at 387v cp803/cp804/cp805 at 387v
On the cold side caps c9454/c9354 at 191v but c9154 fluctuating between 126v-115v and c9254 fluctuating 190v-160v happens between screen BL flashes bright then goes back to regular brightness

[nomoresonys]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

So do Diah's test in post #30, he can help you, usually involves unhooking cable from powerboard to mainboard and using resistors to fully turn on powerboard, then if the voltages are not correct, need to fix the powerboard as suggested. Try the simple hairdryer test also, need to verify that powerboard is 100 percent, can then move on to other stuff if needed.

[nomoresonys]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

Try heating the electrolytic caps up with a hairdryer for a couple few minutes, then try the tv, see if there's any difference and recheck voltages, do it while it's still hot, don't wait til it cools down.

[Diah]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

Ok did the above with 1k Resistor jumped from A5v to each on/off pin results in B13v at 8.04v and B5v at 4.49v will check opto couple next

yours PSU had not enough juice ../ weak . BTW you didn't write any things about pns Vamp 13V... so you need to work on the PSU include to measure all CAPs MSR

[cekanayake]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

A5V are the STBY. so there are 2 scenario of fault
1- one Opto coupling which switch PS on are fault/ not stable so the circuit power on off you need to follow PS ON/ OFF pin to know which Opto and test..
2- boot loop on MB
to be more sure you need to test the power supply complete as stand alone ... when all pins output on the socket correct value and stable include the pins Vamp 13V. at this stage if every things fine then the MB are in boot loop.

BTW use 1K ohm R with testing when you bridge A5V to any other ON/OFF pins.

Ok did the above with 1k Resistor jumped from A5v to each on/off pin results in B13v at 8.04v and B5v at 4.49v will check opto couple next

[Diah]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

So measure A5v shows constant 5.3v does this mean main board fault?

A5V are the STBY. so there are 2 scenario of fault
1- one Opto coupling which switch PS on are fault/ not stable so the circuit power on off you need to follow PS ON/ OFF pin to know which Opto and test..
2- boot loop on MB
to be more sure you need to test the power supply complete as stand alone ... when all pins output on the socket correct value and stable include the pins Vamp 13V. at this stage if every things fine then the MB are in boot loop.

BTW use 1K ohm R with testing when you bridge A5V to any other ON/OFF pins.

[nomoresonys]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

I think the issue is with the mainboard.

[cekanayake]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

in this case.. u need to check pin A5V if its stable
if stable mean pin 20 power on caused by Main boards didn't boot ( boot loop)
if its not stable then the issue at PSU

So measure A5v shows constant 5.3v does this mean main board fault?

[cekanayake]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

Ok, now do the test with one cable at a time unhooked from tcon to panel, then try turning on tv, see if you get a display or what happens, best policy is have tv unplugged from power whenever unhooking or hooking cables, so you don't get any errant surges or such.

Ok. Tested with either cable and both cables disconnected from the t on board to the panel and symptoms are the same cycling and flashing the BL. Does this mean fault in PSI or main board or tcon board?

[cekanayake]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

When I take out both(B13v)s (with B5v on)and try it still cycles but the BL does not flash. When I take out the (B5v)s leads(with B13 on)it goes back to doing the original standby flashing twice 5 times over and over but the BL flashes. I didn’t get to disconnecting the tcon cables one by one as that would mean that I have to take this giant tv and lay it flat. Probably do it tomorrow morning. Thank you Diah and nomoresonys.

[Diah]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

my POST #10
try to slide out the 2 wires of B13V from the socket of pins 7&9 at PSU side, then plug the tv in wall and see if it boot complete and BL stay on. they are for sound and t-CON. if the issue same bootloop... pput them back and remove B5V wire and try

[nomoresonys]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

Ok, now do the test with one cable at a time unhooked from tcon to panel, then try turning on tv, see if you get a display or what happens, best policy is have tv unplugged from power whenever unhooking or hooking cables, so you don't get any errant surges or such.

[cekanayake]

Re: L65X1Q_DHS / BN44-00627A Samsung UN65F6400AF Standby blinks twice five times

Ok, now try it with the cable from powerboard to mainboard unhooked, see if backlights come on steady and stay on.

Yes. With main board disconnected backlight stays on