Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

[kca]

Hello all ~

I’m working on this Samsung 60” LED and purchased a new main board a couple of days ago that did not fix the 5 blink issue. The original main board’s HDMI ports (all 4 of them) failed to work and no amount of reflow remedied that.

This 5 red light blink code on the front panel LED is followed (about 15-20 seconds afterward) by an automatic reboot, and results in 5 more red light blinks. Then the entire cycle repeats itself indefinitely.

No picture. No sound.

I tested all the voltages coming out of the power supply and also their counterpart voltages at the connector on the main board (both the original main board and the newly purchased one).

I found something unusual, I think. The line marked SDA was initially reading only 0.6. I think this needs to be st or around 3.3v. The SCL line, adjacent to the SDA, seems to read properly at 3.6 or 3.7.

Then, when I retested all the same voltages the next morning the SDA line was then reading 2.6v instead of 0.6. Here are my questions:

1. Does a SDA voltage usually read 3.3 volts?

2. If so, does the 2.6 voltage account for the 5 blink error and the no picture / no sound / reboot cycling described above? In other words, is there a minimum voltage (perhaps 3.0 or higher) that this SDA line needs to operate at in order to not cause an issue?

3. What would account for the jump from 0.6v to 2.6v on the SDA line when I changed nothing overnight?

Thanks for any and all help you can provide. I’ll add some pics soon, but the only issue I can directly determine at this juncture are the mysterious and likely insufficient voltage on this particular SDA line.

~ kca

[Diah]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

known fault at F serial . fault Caps at Cold area power boards.... start from there.... but put back your original HIDMI fault MB in place

[kca]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

UPDATE:

Checked all the caps on the power supply board. All OK. At that point, I measured the voltages at the exit connector of the power supply board with the end of the cable at the main board fully disconnected.

Now, the 2,6v reading on the SDA line is reading 3.6. So, with no main board in play, the power supply board seems to be fully functioning. All 13 voltages read at or slightly above the levels indicated on the printed circuit board itself. Note: The primary voltages are supposed to be 13v, according to the print, but all six of those are all reading at 14.2. I think this is a non-issue, but please correct me if I’m wrong.

What appears to be happening is that when the data is transferred to and from the main board it immediately drops the voltage to this lower, 2.6v level.

Questions:

1. Is this drop on the SDA line normal, or is this the manifestation of a fault on the main board? Strange that the SCL (clock) remains steady at 3.6 or 3.7 in all circumstances.
It’s beginning to feel like the 2.6v might be a normal drop as the data only needs that much to execute its tranfer(s)?

2. Can the T-Con board be involved in this issue?

3. I still get the 5 red blink / cycling pattern as previously described when the main board is disconnected from the power supply board. What does this indicate, if anything?

Next, I’m going to put the original main board back in and check all the voltages again. Will report when that’s accomplished.

Thanks in advance ~

~ kca

[nomoresonys]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

Checked all the caps, in what manner did you check them?

[kca]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

Thanks for the help so far. Nomoresonys ~ Here’s an update that will likely reorient us:

Put the original main board back in. Whereas this read 0.6v on SDA at the main board’s connector a few days ago, it now is reading a full 3.5v on both the main board connector side as well as the power supply board connector side. It all appears to be correct. Did not see that coming. Note: a few days ago, when I measured, I only did so at the main board connector.

I also plugged and unplugged the T-con board in every logical combination just now to no avail. The 5 red blink / cycling pattern happens in every scenario I’ve tested.

Is there any explanation why ine non-working main board would now read correctly on the SDA at 3.5v when it clearly only read 0.6 before at the main board connector?

And, how could one main board read 2.6v while another reads 3.5v SDA? Especially given that both produce the same fault code and cycling pattern. One could say the newly purchased main board is defective, but that doesn’t explain the original main board’s continued issue-producing troubles.

Is there a way I can reset the tv at the circuit boards themselves and would that help?

Quick addendum: All of the aforementioned voltages are perfectly stable. They do not fluctuate in any manner. So, the 3.5 sustained and consistent volts at both the (original) main board AND at the PS side seems to be proof that all the caps and other components on the Power Supply board itself are working properly. Is that the case?

~ kca

[Diah]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

caps fault..... even testing outside will not help... because the legs of caps inside could have issue.. change them you will be fine.

[nomoresonys]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

That is a very good question, wonder if you might have had a bad connection and unplugging and re-plugging connectors made it better.

[nomoresonys]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

I trust you Diah, that's good advice, tv is about 10 years old, who knows what quality of caps they used.

[nomoresonys]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

A good rule of cap changing is use the same uf and go up a little in voltage, lots of times they use less than adequate caps to cut production costs to the bone and of course make it non-functional just outside of warranty.

[kca]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

In the process of a few more voltage tests, but I have a couple cap related questions:

1. I’m counting 11 electrolytic caps, 3 ceramic caps and 2 square box type caps on the cold side of the board. Are you recommending that I have to replace them all because there’s no definitive way to assess them?

2. Are we saying that the faulty cap or caps are preventing the LED lights of the panel to initiate and that’s why there is no picture on the screen and no discernible backlights when the cable is disconnected from the main board?

That would make sense to me, as there is some (albeit somewhat inconsistent) proof that all the PS voltages running from the PS to the main board are in fact present.

3. If the problem rests in the failure of the LED panel lights to fire up, how do I determine that it’s not these LED lights themselves that’s at the root of the problem?

I would prefer not to perform a comprehensive cap replacement on the PS if the problem might be foundationally elsewhere.

I’m going to add a few pics to help you visualize how this particular set is designed. The last two in the photo set are stock photos of the front and back of the power supply board (BN44-00656A). The others are of the tv itself.

I’ll also upload one of the entire back of the television and some close-ups of the main board in my next post. Thanks, in advance, for addressing the above questions.

~ kca

[kca]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

A few more images:

~ kca

Looks like the photos got uploaded in upside-down fashion again. I don't know why that happens sometimes. But you get the general idea of the layout.

[nomoresonys]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

Try heating just the round electrolytic caps with a hairdryer for a couple minutes, then try the tv, see if there's any difference, DON'T wait til it cools off to try it, it's just a test that can let a marginal/bad cap work for a very brief time if it isn't too far gone. Many times it's the electrolytic caps that puke out first, so those are the ones to check or replace first.

[EazyBone]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

Generally with Samsungs at least last 6 years roughly, when you disconnect the main board from the PSU and leave the LEDs connected and plug it in, the LEDs should light up. If not, it's the power board or LEDs. This may be older and not the case but you can try. Otherwise LED tester works, maybe someone can tell you how to test the ribbon style as I don't know.

I would try to test the LEDs first.

Hey Sony, maybe you seen my other thread but applied here also.
If the cap is 450v 10 uf, what voltage would you up the cap to?

[kca]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

Alright.

Good idea with the hair dryer heat. I’ll try that next. Hopefully that triggers something and narrows down the bad cap search.

There are no backlights. Those have been out for about a week now. When the original main board was in place (and the only problem was that the 4 HDMI ports were not functioning) then yes ~~~ I was able to disconnect the cable to that main board and get the backlights to illuminate the entire screen. I’m not sure why the backlights ceased to function.

Thanks guys.

[lotas]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

The problem you have, as always, is in the xxF8000 series in the motherboard.

[nomoresonys]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

Generally with Samsungs at least last 6 years roughly, when you disconnect the main board from the PSU and leave the LEDs connected and plug it in, the LEDs should light up. If not, it's the power board or LEDs. This may be older and not the case but you can try. Otherwise LED tester works, maybe someone can tell you how to test the ribbon style as I don't know.

I would try to test the LEDs first.

Hey Sony, maybe you seen my other thread but applied here also.
If the cap is 450v 10 uf, what voltage would you up the cap to?

I think with the bigger voltage caps like the 450 it's probably pretty safe to stay with the same voltage but if you put a 500 in there it would be ok too.

[nomoresonys]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

The problem you have, as always, is in the xxF8000 series in the motherboard.

Can you elaborate, which part of the mb?

[lotas]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

EMMC, micom power (3.3v), if 4 hdmi ports do not work, then something probably slipped (lightning, hot plug) at the input of any hdmi, the processor could be damaged.

[nomoresonys]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

Ok thanks, it seemed like from your post, that this series has a known weakness/issue with the mainboard.

[kca]

Re: Samsung UN60F8000BFXZA ~ No Picture or Sound - 5 Res Light Blinks

Yes, I figure the processor is damaged on that original main board. Reflowing it had no effect. I tried it twice, actually, about 5 days apart from one another. Baked the board in the oven at 385 degrees for 10 minutes each time. That method has worked about 75% of the time over the years whenever the HDMI ports are the only thing defective on a set.

At that point the screen still lit up and I watched tv via the coax cable for a couple days until the picture quality drove me crazy. That’s why I finally decided that the HDMI ports would likely never work again and it was time to purchase a new main board and hope it worked.

The led panel lights seemed to go out shortly after the 2nd reflow attempt. Not immediately, as I recall, but within an hour or so. No popping sound or anything of the like. Just stopped working altogether when I turned the set back on at that particular juncture.