Samsung DLP LED Driver Issue BP96-01803A

**Diah** · 01-14-2019, 09:37 AM

Re: Samsung DLP LED Driver Issue BP96-01803A

i tell you from my way to deal with DLP devices such projector which are the same principle as your TV
the way i check disconnected the 3 LED from the driver board and feed them with 12 V. to see if they are working stable or flaking or one off. when they are good. i fo to next step to foul the LED driver board to sent signal o main board that LED are on. to check if the DLP had issue by feed the RGB LED one by one with external 12V if the DLP turn off mean the issue not at LED driver.

**richr69** · 01-14-2019, 02:14 PM

Re: Samsung DLP LED Driver Issue BP96-01803A

Hi Diah,

Thanks for the reply.

I had some difficulty understanding.. Are you suggesting that I power the individual RGB LEDs (one at a time) by an independent power source, and then turn the TV on to see if get the blank screen?

Thanks.

**Diah** · 01-14-2019, 02:49 PM

Re: Samsung DLP LED Driver Issue BP96-01803A

Originally posted by richr69

Hi Diah,

Thanks for the reply.

I had some difficulty understanding.. Are you suggesting that I power the individual RGB LEDs (one at a time) by an independent power source, and then turn the TV on to see if get the blank screen?

Thanks.

No Not exactly what meant. you cant do this.. let me explain it in other way
1- disconnect the RGB LED from the driver board
2- Poser them each one with external power supply 12 Volts. at this stage you can see with your eyes not on the screen but where the LED case mounted that they turn on in good way, not Flecking or one turn off after 1-10 second
all above steps doing them with out turn on the TV at all.

second there are SMPS on LED driver board which are responsible to send signal to MB Thant LEDs are ON. so the DLP circuit starting. this we can foul it by short contact to let it switched the MB ON. if you find this then you can turn on the TV .. and keep the LED feeds from external PSU. one by one. now you can watch on the screen if the DLP will turn off or keep on. if it turn off as you have before then the fault not with LED or driver.. much easy i cant explain more with out clear photos of the LED driver Board from both side

**richr69** · 01-18-2019, 10:50 AM

Re: Samsung DLP LED Driver Issue BP96-01803A

Well, I tested the 3 LEDs with a 9v battery, and all 3 LEDs stay on without any issue. The Primary SMPS has the Sam-Wha caps (which I replaced on the Secondary SMPS which were bad), but I did not replace any of them, given none of them appeared bad or puffy. I guess I can go ahead and replace those caps (cheaper than replacing the LED Driver). If that does not fix the issue, I guess this project will come to a conclusion.

**budwich** · 01-18-2019, 11:01 AM

Re: Samsung DLP LED Driver Issue BP96-01803A

are you able to power up the system with onlly one of the leds disconnected at a time... I thought that was possible but perhaps not. IF you are able to do that, then you can cycle thru this to see if one of the units is the problem or not.

**richr69** · 01-18-2019, 02:57 PM

Re: Samsung DLP LED Driver Issue BP96-01803A

I do not believe I actually have tried that. Thanks for the suggestion. I'll give it a shot.

**budwich** · 01-18-2019, 03:02 PM

Re: Samsung DLP LED Driver Issue BP96-01803A

If it potentially starts and works, especially with any "2 configuration", that would may point you to a common supply issue that is overloading when all 3 are connected. If a certain "2 configuration" works better than others, then that might isolate to a given led driver.

Note: i believe that the leds are "switched" (ie pulsed) at 60hz... is that the flashing rate that you are seeing... faster , slower ?

**richr69** · 01-18-2019, 03:11 PM

Re: Samsung DLP LED Driver Issue BP96-01803A

Unfortunately the LED driver is a single board, which all 3 LEDs connect to. So if it turns out to be an issue with the LED driver, I will have to replace it. But, maybe this may isolate the circuit on the driver, causing the issue.

**richr69** · 01-19-2019, 11:25 AM

Re: Samsung DLP LED Driver Issue BP96-01803A

The flashing LEDs I was referring to are the ones
indicating the power status on the front of the TV.

the RGB LEDs inside the TV appear to be fine. I disconnected 1 and had 2 always connected.The issue with tv screen turning off still ocurred.

This may be a lost cause.

**budwich** · 01-19-2019, 11:43 AM

Re: Samsung DLP LED Driver Issue BP96-01803A

:-( thanks for the clarification as my reading was poor on your first description.

So you are saying that it doesn't matter which LED output is disconnected, the set responds the same with shut down? The dlp sets "normally" lose the red led as it gets the hots. I have the next series of samsung dlp which has had the dlp chip replaced.

Depending on how much time you want to invest, you might try searching the avsforum in the rear display area / subforum. There use to be a poster there that rebuilt drives and salvage leds. If you get lucky, you might find some of the posts and perhap PM for ideas on what to look for or perhaps find more information therein.

I have to see if I can find my SM to see if there is anything more defined for the "newer" set.

**budwich** · 01-19-2019, 01:07 PM

Re: Samsung DLP LED Driver Issue BP96-01803A

Another suggestion trying locate the faulty part, you try some "light heating" of the caps that you "questioned" in your first post to see if they impact starting or not. Similarly, you could try cooling.

Lastly, if you get the set to run for a bit, you might try to look into the service menu, there is a trouble log (on newer ones) that might help.

**Diah** · 01-19-2019, 01:36 PM

Re: Samsung DLP LED Driver Issue BP96-01803A

Originally posted by budwich

are you able to power up the system with onlly one of the leds disconnected at a time... I thought that was possible but perhaps not. IF you are able to do that, then you can cycle thru this to see if one of the units is the problem or not.

common budwich the RGB LED are in part of LED driver circuit, any one of the 3 fail to turn on the driver will give error to shut down the DLP..

**richr69** · 01-19-2019, 04:29 PM

Re: Samsung DLP LED Driver Issue BP96-01803A

Small recap...

In all the searching I have done, it appears this TV appears to suffer from the 'white dots' issue (fixed 3 years ago), Secondary SMPS caps, and the RED LED burning out.

I fixed the Secondary SMPS and as I indicated i.e. input voltage 300V (coming from the Primary SMPS) and output 12V and 16V voltage (going to the LED Driver). All measure fine.

All 3 LEDs appear to be working

How do you test the LED?

All 3 LEDs appear to light up, so I assume they are fine. When I get into the Service Menu I see all the colors/patterns when I cycle through the various tests.

When,
I have all 3 LEDS connected - TV screen eventually turns off.
I have Blue/Green LEDs connected and Red LED disconnected - TV screen eventually turns off.
I have Red/Green LEDs connected and Blue LED disconnected - TV screen eventually turns off.
I have Red/Blue LEDs connected and Green LED disconnected - TV screen eventually turns off.

In all the 4 cases the screen stays on for awhile. There is no pattern how long it stays on.

Each LED has a thermister on it going to the LED Driver Board. I disconnected them to see if that made a difference, but it did not. I thought maybe one of the thermisters went bad, causing a false indication the LED was bad (apparently not the case).

Unfortunately the Service Manual does not have a schematic for the LED Driver board.

Yeah, poked around the service menu several times. Could not find anything that would indicate anything is at fault. The only time I came across anything, was when I purposely disconnected a LED. I found the entry in the service menu which clearly indicated the led I had disconnected as bad.

I did not think about the hot/cold exercise. I'll try that next when I get a chance.

Thanks.

**budwich** · 01-19-2019, 05:27 PM

Re: Samsung DLP LED Driver Issue BP96-01803A

The other test is a standard "doide check" with a meter.... I think I have seen bias voltage stated somewhere... maybe in avsforum. They are not all the same as the colors are different "substrates".

Like others "design features", most things tend to monitor current as opposed to voltage. It is probably more likely a current (over) condition that is setting the code.

Can you restate / provide more detail on the failure... sorry I am slow.... :-) but does your set shut down with the code / led flashing or you only the led flashing on startup thereafter?

**budwich** · 01-19-2019, 06:12 PM

Re: Samsung DLP LED Driver Issue BP96-01803A

ok.... here is the best hope.... at least with an expert that seems to know about alll thing samsung dlp....... :-) This s the one that I was thinking of... he goes by the handle stanman2242 in the avsforum.com. My bet is that he can give you some tips about how to trouble shooting this further and / or even get you parts (ie. LED's). Anyway, it costs nothing to try.

**R_J** · 01-19-2019, 06:13 PM

Re: Samsung DLP LED Driver Issue BP96-01803A

Have you checked the error led on the driver board? is it blinking? have you tried changinng the switch from int to ext mode?
If you can get into the service menu, that would tell me most of the set is working,
Have you checked the connections on the driver board for the led's? also do the led plugs look ok or are they burnt or discolored?
I have worked on a few of these back in the stone age but only a few, they were not very common and I do remember replacing the odd led and seem to recall over heated connections due to the higher current.

**budwich** · 01-19-2019, 08:27 PM

Re: Samsung DLP LED Driver Issue BP96-01803A

this is the thread that I see good work in and around these sets.
https://www.avsforum.com/forum/63-re...7-89s-502.html

Samsung DLP LED Driver Issue BP96-01803A

Samsung DLP LED Driver Issue BP96-01803A

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