Samsung LN32B360C5DXZA Sound OK, No Video

[Wizard]

Re: Samsung LN32B360C5DXZA Sound OK, No Video

Don't think about it. Test turn on by jumpering with a resistor from standby supply to (power-on) to see if power supply responds at the connector. The powering on sequence is complex due to PFC circuit.

Cheers, Wizard

[Dgtech]

Re: Samsung LN32B360C5DXZA Sound OK, No Video

Here is more of what I am noticing with mine:

All voltages seem OK whenever the board is powered up without the processor board being plugged in. It's as if the processor board is somehow telling the power board to shut down. The 5VDC on the connector is solid, but whenever the other board is plugged into this one via the ribbon cable, it goes from 5VDC to 0 four to five times and then quits.

So ok... When I did this test before, I didnt have the board plugged into the CCFL lamps. Just now, I had the board itself powered up with the CCFL's and just without the ribbon to the control board and guess what, the backlights were on full brilliance (10 mins no problem). I then plugged in the connector and got the usual, power up samsung music/sound - 5 blinks of the power LED - and no backlights at any time.

I'm now thinking that the power board is fine now but somehow the control board is telling it to turn off. Is this sound thinking?

[fastvideo]

Re: Samsung LN32B360C5DXZA Sound OK, No Video

#1 Sound is working. As you have already said at the first post.
#2 Please if you can confirm image is presents with a flash light.

I still think it is only back light problem.
Check back what I have pointed out on post #10, 11 and 14.

If there is no ON signal drive at PC802S, UB802 somehow is turning INV_UVLO to an On state.
Should check if UB802 and related component is having problem.

That is why I ask if I can try forcing the UI801 to On state at post #20 which Wizard doesn't like the idea.

[alexanna]

Re: Samsung LN32B360C5DXZA Sound OK, No Video

So ok... When I did this test before, I didnt have the board plugged into the CCFL lamps. Just now, I had the board itself powered up with the CCFL's and just without the ribbon to the control board and guess what, the backlights were on full brilliance (10 mins no problem). I then plugged in the connector and got the usual, power up samsung music/sound - 5 blinks of the power LED - and no backlights at any time.

I'm now thinking that the power board is fine now but somehow the control board is telling it to turn off. Is this sound thinking?

I am sure there some major differences in Tvs and LCD monitors, But on a LCD when I get back lights to come on only when the ribbon to the LCD panel is disconnected a lot of times it can be traced to a marginal LDO regulator, Have you checked these?

[Dgtech]

Re: Samsung LN32B360C5DXZA Sound OK, No Video

Thanks for the advice both of you.

I have tried to check that voltage out but I can't locate a spot on the front side of the board for that PC802S or UB802.

I think I may have confused the conversation when I thought it was the same problem. I think this is different. I posted the pictures below to show how the backlights work without the control board connected. They will stay on as long as I leave it this way. Have you tried it this way - fastvideo? If the backlights are off on yours under this scenerio, then we definitely have different problems.

When the connector is plugged into it, connecting the control board, the backlights drop out and yes you can see the image with a flashlight.

[Dgtech]

Re: Samsung LN32B360C5DXZA Sound OK, No Video

I also add that I was watching tennis for a while on this set earlier. I noticed that whenever I do have the control board powered up and running, the processor (with the heatsink) gets kinda hot. I can barely keep my finger on it.

[turfman]

Re: Samsung LN32B360C5DXZA Sound OK, No Video

Needed to dig this thread out of the cellar. I have one of these units that the screen just continually blinks on and off. If I unplug the main board it will stay on solid, but no LED's either way.

[BeTronics]

Re: Samsung LN32B360C5DXZA Sound OK, No Video

Thanks for your posts on this unit. The schematics and notes helped get a start to troubleshooting one of these that a friend had. The symptoms were different... no power up and no sound, no musical beeps on power up. Repaired by replacing ZM801 (1N4740A, Zener diode) and QM801 (STU418S, MOSFET) Not sure if it would help in other fault scenarios for this model. Looking at the board, I believe a second diode / mosfet driver is used in the same section, which may could possibly control another portion of the control feedback, allowing the sound to be enabled but still no video... just a thought... not proven ... Brad

[rlega]

Re: Samsung LN32B360C5DXZA Sound OK, No Video

Hello everyone,

I purchased a Samsung LN32B360C5DXZA for $25 and like the title shows, the TV had sound, but no picture.

I searched online for the issue and I found Badcaps. I read all the posts and I saw a picture that someone posted where it shows the 3 diodes. I checked the diodes on my power supply board and got the following readings:

DP810 - 485k (reverse test showed infinite like it should)

DP804 - 506k (reverse test showed infinite like it should)

DP805 - Open diode in-circuit as well as out of the circuit

I did a search online and I was not able to find the same diode (DP805 - MUR360AX SSG 09083).

When it comes to capacitors I can find them online, but I'm having trouble finding the diode. Can anyone give me a hand?

I'm attaching a clear picture of the power supply board and marked the diodes reading.

Thanks

[rlega]

Re: Samsung LN32B360C5DXZA Sound OK, No Video

Hello,

Is anyone able to help me with the diode that its bad on the TV so I can purchase it and replace it?

I found these two online but I do not know if it will work:

1N5408 Rectifier Diode 3A 1000V

1N5400 B, Rectifier Standard Recovery NS, FBGA48

Thanks

[rlega]

Re: Samsung LN32B360C5DXZA Sound OK, No Video

I found replacement diodes for the TV, because I could not find the MUR360AX. I ordered them, and walla, the TV is working.

I found them on eBay (Seller: maziz3)

Thanks

[Lenny63]

Re: Samsung LN32B360C5DXZA Sound OK, No Video

Hello new to this form . my name is Lenny