Samsung 32" ln32b360c5d

[Peale]

Re: Samsung 32" ln32b360c5d

Two of those readings are from one transformer. So, that's good. If I pull it, will it enable it to work, as a test? Or, should I just replace it?

And...where do I get another? IIRC I tried looking for one (with the part number QGAH02107) but didn't come up with much in this country.

[Peale]

Re: Samsung 32" ln32b360c5d

Okay, that's weird. I couldn't find them, before. But, now I see one on eBay, $9.90 shipped, from China.

http://www.ebay.com/itm/1PCS-INVERTE...-/261076811326

[budm]

Re: Samsung 32" ln32b360c5d

Before doing that, with diagram you have for the 289A, please verify that the 13vdc is always present and steady, same for other voltages as shown in the diagram.

[Peale]

Re: Samsung 32" ln32b360c5d

Should I be checking the voltages at CN802, or @ TM801S?

[Peale]

Re: Samsung 32" ln32b360c5d

I'll start with CN802.

16 GND - 0
15 GND - 0
14 DET_5V - 0
13 EPWM - 5.01
12 INVERTER_ON/OFF - 4.46
11 13V - 13.2
10 13V - 13.2
09 GND - 0
08 5.3V - 5.28
07 5.3V - 5.28
06 GND - 0
05 GND - 0
04 13V - 13.19
03 GND - 0
02 - 5.3V -5.28
01 - POWER_ON/OFF - 2.15

[budm]

Re: Samsung 32" ln32b360c5d

OK, Please see PDF.
You can defeat the shutdown circuit by grounding the FB pin then look at the screen real close to see if all the lamps are OK or if they all lit up.
You can monitor the FB pin to see what you have as I explain how it works in the diagram attach.

[selldoor]

Re: Samsung 32" ln32b360c5d

Off Topic - Budm I'd like to third/fourth/fifth the support for you to stay. I dont have any sort of background in electronics and dont understand circuits much, shaky on data sheets but have a good eye and memory.
I quite often get stuck and just hope at some point you will see I am struggling and come to the rescue.

I also get frustrated and now regularly just let threads go. I am sometimes on the point of posting a rude response then scrub it and get a coffee.
I choose more who to help.

I am best sticking with monitors - I almost understand them but even so
there is a current thread where my first impression was -This is a lazy B
All the information is there he just cant be bothered to read it.

[Peale]

Re: Samsung 32" ln32b360c5d

OK, Please see PDF.
You can defeat the shutdown circuit by grounding the FB pin then look at the screen real close to see if all the lamps are OK or if they all lit up.
You can monitor the FB pin to see what you have as I explain how it works in the diagram attach.

In your diagram you have both "B" and "FB" circled. And, there's more than one of them. Do they all reference the same point, but on different places on the board?

I've been trying to figure out where one of the FB points is. For example, I see that one comes off RI875. That seems to go to off and fork, toward QI814 and RI818.

I figured I'd check the voltage at pin six of UI802 (ref v should be 1.63V) but since it's on the bottom, how do I check it with it plugged into the lamps? Or, do I not need to have it plugged in to test that?

[budm]

Re: Samsung 32" ln32b360c5d

'B' are all connected together, 'FB' are all connected together.
The easiest way is to locate the left side RI816 as shown in the diagram or the MOSFET QI814 Drain pin, just solder a small wire to it and bring it out so you can attach it to the meter.
You have to have the TV plugged in to test the voltages.

[Peale]

Re: Samsung 32" ln32b360c5d

'B' are all connected together, 'FB' are all connected together.
The easiest way is to locate the left side RI816 as shown in the diagram or the MOSFET QI814 Drain pin, just solder a small wire to it and bring it out so you can attach it to the meter.
You have to have the TV plugged in to test the voltages.

Done. End of a piece of wire soldered to the left side of RI816.

Black lead on meter to ground, red lead to wire.

Reading -0.01 when power is first applied, 0.00 after the lamp shuts off.

If I read what you wanted me to do, above, correctly, I should take the wire and attach it to ground, correct? It didn't do anything new.

[Peale]

Re: Samsung 32" ln32b360c5d

You have to have the TV plugged in to test the voltages.

Sorry, I should have been more clear. Of course the TV has to be plugged in. I was referring to the PS board plugged into the set (attached to the CCFLs). Or, if I could just flip the board over, and take a direct reading of the 1.63V reference voltage.

[Peale]

Re: Samsung 32" ln32b360c5d

I'm going to have to shelve this for the moment. I slipped and broke one of the inverter transformers. And, I couldn't have been lucky and broken the one that read reading off, of course not...

I'll revisit this once I get replacements.

[budm]

Re: Samsung 32" ln32b360c5d

OK, the FB for the Isense shorted to ground and the lamps still do not stay on, at least that eliminate of possible cause of the lamps shutdown on the Isense line. Need to look somewhere else next.

[MisterD]

Re: Samsung 32" ln32b360c5d

Don't quit. Your input here is much appreciated. I don't think I could continue without you.
You will get people like that all across the internet.

I sure would hate to see you leave Badcaps Bud, you have helped me several times on different LCD TV's and all are working now, I hate that this happens also, I just don't understand why people want to repair at a component level then just disappear right in the middle or near the end of the troubleshooting after you do all the hard work for them. I hope you both stay, I very much appreciate all you guys do.

[dejesus]

Re: Samsung 32" ln32b360c5d

Tell you what, you two guys (tom66 & budm) really make a diferent in this forum. Hope you guys never quit.

[craigc15]

Re: Samsung 32" ln32b360c5d

This problem is very likely caused by a defective diode in the PFC circuit (DP805). Apparently there is a service bulletin for this problem. I just fixed a TV with this problem and when I tested the diode out of circuit, it tested fine in diode check mode and resistance mode (in both directions).
The defective diode causes a "UVLO" failure in the backlight circuit because the voltage across the main cap is not as high as it's supposed to be. I'm getting around 340V with 120V line, but with the bad diode I was only getting around 320V.

[pistonesal]

Re: Samsung 32" ln32b360c5d

Hello everyone. I have one of these 32" Samsungs but mine backlight comes on and works for hours, sometimes it shutsoff and sometime if I turn off the tv and then turn it back on the backlight does not turn on. If I unplug it and plug it back in sometimes the backlight does and sometimes it does not turn on. Its driving me nuts. Has the BN44-00260B Power Supply and if I unplug the CN802 cable from main board the backlights do come on. I replaced the DP805 and no luck. I also replaced ZM801, IC 801S. WHat is the preoblem? Is it the main board or the power supply (IP board)? What parts do I need to replace? I don't want to spend like $100 on a board espcially since I dont know which is the culprit board. Anyone have any suggestions? Pleas ehelp.. thanks

[Shane711]

Re: Samsung 32" ln32b360c5d

I also have this TV and it turns on with the chime and the backlight comes on and stays on but there is no image. I am pretty sure it is the main board so I believe it is the EEPROM chip. I just bought a EEPROM for $8.00 so I will post what happens after I install it.

[budm]

Re: Samsung 32" ln32b360c5d

Did you check and see if the T-CON is getting 12V on both ends of the SMD fuse?

[Shane711]

Re: Samsung 32" ln32b360c5d

This TV does not have a T-Con board. The ribbon from the main board goes strait to the screen. I however could have checked the boards on the screen for fuses, I did not think of that.