UN55D6000 Blinking Standby Light

[tom66]

Re: UN55D6000 Blinking Standby Light

Very unlikely to be bad caps on a new TV like this... not saying it's impossible, but it's unlikely. Startup capacitor if anything could cause fault.

[mmartell]

Re: UN55D6000 Blinking Standby Light

Could a bad start up cap cause all voltages to be output AND cause voltage on the input pins ?

[mmartell]

Re: UN55D6000 Blinking Standby Light

If I remember well, there should be a flip up tab and then squeeze and pull.

Thanks I will try that.

[mmartell]

Re: UN55D6000 Blinking Standby Light

Some discussion here leading to main board conclusion.
http://www.justanswer.com/tv-repair/...-warranty.html

No schematic I'm afraid.

The guy in the article never came back and confirmed the suspicions of the tech. FWIW the previous owners of this set stated they took it to a local shop and he told them the mainboard needed replacing. Don't know if this is a "common knowledge" thing or what.

I can understand the possibility of the mainboard being defective but I can't understand why the PS is acting the way it is.

Perhaps that is its normal operation without load ?

[tom66]

Re: UN55D6000 Blinking Standby Light

You could try applying a light load, around a few watts, to see what it does.

[mmartell]

Re: UN55D6000 Blinking Standby Light

Does Samsung use active LOW for PSON ? That would explain some of what I'm seeing here. As far as voltage on that line without the mainboard connected I can only guess that PSON is a bi-directional data line for which there is some chatter between the mainboard and power supply at power on. THAT would fully explain what I'm seeing. That and the fact that I may have a defect in my led strip(s) causing the PS to respond with an error back to the mainboard.

[johnboy1313]

Re: UN55D6000 Blinking Standby Light

mmartell, I was pointed here by the post you made in the other UN55D thread. As you saw, I have the same set with a cracked screen. If no one else answers your question, I'll try to get the answers tonight.

[mmartell]

Re: UN55D6000 Blinking Standby Light

Hi johnboy, I have answered a few myself.

There is a tab that flips up on the lvds cable connector nearest the board that allows you to squeeze the connector (as one might expect!) and remove the lvds cable from the socket. With the T-Con disconnected I still had the same symptoms.

This set does use an active low for PSON. It is 3.3v in standby and pulled low for power up. Since I see voltage on that pin even with the mainboard disconnected I believe I have at minimum a problem with the SMPS.

I'm considering using a PSU from a different Samsung I have here and rigging it to see if I can at least get the mainboard to stop flashing and power up properly. Will have a look more at that tonight.

[Ltank]

Re: UN55D6000 Blinking Standby Light

I got this info for a UN55D3003 might help

[mmartell]

Re: UN55D6000 Blinking Standby Light

Thanks tank will have a look.

[mmartell]

Re: UN55D6000 Blinking Standby Light

Ok need some help here thinking this out.

I believe I have a faulty power supply. 5V Standby is rock solid. However when the secondary voltages come up the unit shuts down (protection ?) and the cycle starts over again.

I think there is a short because I'm reading voltages on the PSON, BLON and DIM pins.

Doesn't sound like a capacitor issue does it ? I've heated the board anyway with no change.

Where should I be looking ?

[mmartell]

Re: UN55D6000 Blinking Standby Light

Here are some pics of the board. Is there some common area that would leak voltage to the input pins ??

[Hudey]

Re: UN55D6000 Blinking Standby Light

Hi, I have a un40d6000 with the same symptoms, all voltages are switching
on and off, except for the 5vsb.. , ordered a psu, installed it no change, i also disconnected the t-com still no change, i can't find schematics for it,
i ordered a main board will post when i recieve it .
Peace.

[mmartell]

Re: UN55D6000 Blinking Standby Light

Hudey do your backlights come on at all when you plug it in with mainboard disconnected ?

[johnboy1313]

Re: UN55D6000 Blinking Standby Light

FYI, yesterday when I was stripping my tv, I had the LEDs unplugged and tried to fire it up. The led on the front flashed over and over and the PSU clicked repeatedly.

[mmartell]

Re: UN55D6000 Blinking Standby Light

Well having bad leds is a possibility too but I don't know how to test the strips when I'm not sure in the first place if my power supply is good.

[Hudey]

Re: UN55D6000 Blinking Standby Light

Hi,
Pins 3 and 5 are physically connected on the psu ill try to post a pic
2, led panel will not light , main has to keep the psu fully on, some can be tricked to stay on , i will have to look into it , w/o schematics its kinda hard.
i still have not received the new main yet. will post as soon as its in,
Hope this helps,

[mmartell]

Re: UN55D6000 Blinking Standby Light

Yes it does help, Hudey, thanks for chiming in and do post back with results.

[Hudey]

Re: UN55D6000 Blinking Standby Light

Hi, the main board fixed it. , un40d6000 . same board different f/was a un55d6000
Good luck , Peace

[mmartell]

Re: UN55D6000 Blinking Standby Light

Ok thanks for the update. Since I need a mainboard as well I'm tempted to upgrade to a 6400 or even higher if I can confirm compatibility.

I still wonder if the eeprom is messed up. The voltage regs are working - at least during the "on" portion of the cycle.