Trying to Save - Samsung 65" The Frame (QN65LS03B) with no signs of life (One Connect Box)

[KYBOSH]

I picked this one up today.
Previous owner says no signs of life.
TV looks immaculate and its a 2022 model year so I thought maybe the one connect cable was damaged.
Got it home and put it on the Kill-A-Watt power meter and it was completely dead.

The TV model is QN65LS03BAFXZA - version: CB06
The One Connect Box BN44-01066D / BN96-54788Q / BN39-02470A.

I immediately remembered EazyBone's Samsung The Frame TV no power....One Connect thread and am preparing myself to tear the One Connect open and hunt for dead parts.

Will keep you all posted!

[CapLeaker]

Yeah, take that one connect box apart, remove the heatsink and reflow the 3 large IC's. My guess is that the fan isn’t spinning either at the moment.
There are videos on YouTube on how it's done,

[EazyBone]

Nice tear it open and let's see!

[KYBOSH]

Per your request! CapLeaker EazyBone







Two bad components.
Fuse: 250V 3.15A
Mosfset: MagnaChip 70R380P

Question: I read that MagnaChip went out of business not too long ago.
I see a few of these fets online for ordering BUT i have a few of these MagnaChip Mosfets in my collection.
Namely 60R360P, 60R580QS, 60R360QS, 60R360Q, 70R600P and 80R450P.

There is a video i came across explaining Mosfet replacements that I will look at tonight.
Then I will have a look at the datasheets to see if I can substitute one of these for the blown one.

My guess is that the fan isn’t spinning either at the moment.

Wait... These things have fans?
I didnt even notice it!

[EazyBone]

They sell these on AliExpress. Or old donor boards. I'm pretty sure mine blew with a blue cap also, might want to replace that. It is hidden under all that silicone

[KYBOSH]

Great Video! Seems like substituting MOSFETs are quite similar to substituting capacitors.

I found that I have an Infineon 11N80C3 (TO-247) in my bin and I think this might just work for the application....

Original MagnaChip MOSFET (70R380P) is:
V_DS = 750V
R_DS = 0.38Ω typ. / 0.38 max @ 10V, I_D = 3.2A, 25°C
I_D = 11A @25°C

Infineon is:
V_DS = 750V
R_DS = 0.38Ω typ / 0.45Ω max @ 10V, I_D = 7.1A, 25°C
I_D = 11A @25°C

Only issue (if it is an issue) is the bigger package of the TO-247 but I will have to see.
And I may have to insulate it from the heatsink but I will have to take a look at the package.

The MagnaChip 80R450P I have may also work as it well but it has a R_DS 0.45Ω I dont know if this is too much but the video says the lower the better). Plus and drain leg might be too short (ripped off during removal).

Any thoughts?

[KYBOSH]

They sell these on AliExpress. Or old donor boards. I'm pretty sure mine blew with a blue cap also, might want to replace that. It is hidden under all that silicone

Haha! Im re-reading your thread now and we are actually going down the exact same thought process (even asking about substituting 80R450P!) Pretty funny. Thanks for the tip about the blue cap. Would have missed that completely. WIll check it when I get back to the bench.

[EazyBone]

I think it'd be wise to replace it anyways but that's only based on watching nicktv videos and seeing them explode.

https://a.aliexpress.com/_mL0mlKF

[CapLeaker]

Aah! PSU… I thought is was that damn unobtainable one connect box that’s broken.
I used TO247 MOSFETs to replace blown TO220 MOSFETs before. Works fine, you just have to fiddle around with the legs and maybe drill a new hole into the heatsink or put in a different heatsink altogether.

[KYBOSH]

I think it'd be wise to replace it anyways but that's only based on watching nicktv videos and seeing them explode.

https://a.aliexpress.com/_mL0mlKF

You are right... but...where is the fun in that???
I tossed in the 80R450P to see if i can get signs if life but still nothing.
My ceramic cap seems to be okay too.

I thought of eaarnoudse's post about the blown resistor and dodgy IC.
Sure enough the 2R20 cap was gone. Replaced that but still no signs of life so its likely the SSC3S211 which i would not have a spare of ... unless I check some Samsung part boards.
If I dont I'll order it from Ali-E along with the proper 70R380P replacement MOSFET.

Aah! PSU… I thought is was that damn unobtainable one connect box that's broken.
I used TO247 MOSFETs to replace blown TO220 MOSFETs before. Works fine, you just have to fiddle around with the legs and maybe drill a new hole into the heatsink or put in a different heatsink altogether.

So very tempted! The TO247 is pretty big though and I woud have to tap a new hole in the heatsink to secure it. The 80R450P will do the trick for now.

[EazyBone]

I might have an extra ic actually. Where you located? Us?

[EazyBone]

Yeah, take that one connect box apart, remove the heatsink and reflow the 3 large IC's. My guess is that the fan isn’t spinning either at the moment.
There are videos on YouTube on how it's done,

What videos you talking about also? Can you show a link

[KYBOSH]

I might have an extra ic actually. Where you located? Us?

Atlanta GA. I'll PM you. Thanks!

[EazyBone]

In the mail, we close so should be like 2-3 day

[CapLeaker]

What videos you talking about also? Can you show a link

Here ya go EazyB!
https://www.youtube.com/watch?v=HKRJDb2S2_U

[KYBOSH]

Look at what EazyBone sent me today!

[EazyBone]

Now let's see the hack job and if it works.

Also my tariff is at 400%

[KYBOSH]

.
It powered on with no issues!

i plugged it up without the One Connect cable/TV attached and it drew 2.0w for a second, then 1.0w for a second, then 0.5w for a second, then it went to 0w and stayed there. I then connected the cabel/TV and it came alive. Drawing 57w in low power picture frame mode and 177w in full TV mode.

The 3S211, 70R380P and 2.2ohm resistor did the trick.

PRO TIP! The 3S211 seems to be held on with 2 dabs of adhesive which makes it hard(er) to remove under hot air. If you are not careful you run the risk of scorching the board around/under it bcos you are still heating it up waiting for the IC to come off. Luckily i tinned the legs which made things 10x easier and used a tweaser to pull the IC off. I imagine this thing gets hot and they didnt want it to move if the solder started flow little by little over time. It is hanging upside down after all.

Also it dawned on my later that CapLeaker's comment about a fan was a joke (there is no fan in these units) but it inspired me so i ordered a couple 25mm 12v brushless cooling fans from Ali-E. I will put one in the OCB to blow directly on this area where the MOSFET is. But i will tap into a 5v rail (usb?) so the fan will run quiter at half speed. This along with a generous amount of thermal paste/pads should keep this thing nice and cool.

[EazyBone]

Haha very nice. Yes tin on each leg is always a must before heat gun. Hell tin on everything before heat gun is almost a must, they use lead free solder and we all know that just isn't good

Still surprises me that these expensive ass frame tvs are edgelit.

Did you throw in that mosfet too?

[KYBOSH]

Still surprises me that these expensive ass frame tvs are edgelit.

Did you throw in that mosfet too?

yes i absolutely did. Didnt want to be inconsiderate to your kindness by using an out of spec component wheb there was no need. Maybe one day if i have a burner OCB i will experiment with that alternative.

i think edge-lit is the only way you can get these TVs this slim unless you go OLED but then im not familiar with those or if you can have all the electronics in a remote OCB like you can with these.

anyway im pretty happy to have learned a thing or two with this nice little fix!

I owe you one Sir.
thanks again!