BN44-00517C dead - blown cap, resistor and fuse

[lotas]

OK. Does it sound like number 1 is faulty as I get a sound and a meter reading in both directions?

I answered in post 37 that a 68 Ohm resistor was soldered in parallel to it, so the multimeter shows this resistance! To be sure, unsolder it and check.

Only they (zener diodes) should not be confused with each other, each zener diode has its own marking and each marking has its own characteristics!

[dazzystar]

so I have scraped around the area and the readings from all 4 diodes are the same as before. Is it worth repairing or should I give up?

[vinceroger69]

Depending on what the tv is worth to the customer or if for re sale china do a board but not cheap maybe worth sending the seller a lower offer Substitute bn44-00517c Power supply board for Samsung TV Maintenance Accessories - AliExpress

[dazzystar]

Thanks but it's my TV not a customers. Also that aliexpress board is NOT compatible with the TV. Shame. We'll take it to the recycling centre.

[nomoresonys]

Just make sure you are testing the diodes correctly, they are pretty cheap to buy, of course shipping is never very cheap, check youtube, there's plenty of component checking videos.

[cheeky2]

Thanks but not sure which one(s) you mean. Here's a pic of the new PWM chip.

Your pin 5 doesn't appear to be connected up to anything! Did you take a picture of your pcb before you did the soldering? Also your pin 4 looks like the track could be broken as well where the masking is removed and the copper is exposed.

[dazzystar]

Your pin 5 doesn't appear to be connected up to anything! Did you take a picture of your pcb before you did the soldering? Also your pin 4 looks like the track could be broken as well where the masking is removed and the copper is exposed.

Pin 5 doesn't connect to anything. I didn't take a pic beforehand.

[dazzystar]

Just make sure you are testing the diodes correctly, they are pretty cheap to buy, of course shipping is never very cheap, check youtube, there's plenty of component checking videos.

I've tried testing the diodes with my DMM. The only one I get any reading from is what I described earlier so I have no idea now what to try.

[nomoresonys]

Probably best way to test, specially if they seem to test not right in circuit is to remove and test out of circuit, Look there, 13 minute mark, checking diodes : https://www.youtube.com/watch?v=l7WdQoPGjrU

[lotas]

Your pin 5 doesn't appear to be connected up to anything! Did you take a picture of your pcb before you did the soldering? Also your pin 4 looks like the track could be broken as well where the masking is removed and the copper is exposed.

For this SSC2S110 PWM, pins 3 and 5 are not used.

[dazzystar]

Yes. I saw that. Thanks.

[dazzystar]

Can anyone help with what value(s) those zener diodes are please so I can order some replacements. Also, does anyone have a link to a circuit diagram at all?

[Jonny B]

Hi, I have the same issue and rather than throw the TV away I want to try and fix it. I have sourced some of the parts but I'm struggling with the resistor. If anyone could post a link to the correct one I'd really appreciate it.

[nomoresonys]

Budm explained it in post #2, 0.24ohm resistor, doesn't have to be flame proof, or are you talking about another one, youtube is your friend for how to test components if needed. Resistor checking chart there for thru hole: https://www.digikey.com/en/resources...tor-color-code Surface mount chart: https://www.digikey.com/en/resources...-resistor-code

[Jonny B]

Budm explained it in post #2, 0.24ohm resistor, doesn't have to be flame proof, or are you talking about another one, youtube is your friend for how to test components if needed. Resistor checking chart there for thru hole: https://www.digikey.com/en/resources...tor-color-code Surface mount chart: https://www.digikey.com/en/resources...-resistor-code

Thanks for your swift reply.

The only reason I ask for a link to the correct one is that I have been looking for a while now and still seem to get lots of options even when I find a 0.24ohm resistor.
Other factors that I can see when looking include,

• Composition - wire wound, metal film, metal oxide film
• Power (watts)
• Operating temperature
• Temperature coefficient

Again, any help would be really appreciated.

[nomoresonys]

Some there, I'm not sure what watt yours is but I wouldn't put a half watt where a 1 watt was, you can tell by measuring the diode, measure yours not including the leads, then just search for diode size, the one watt are much bigger than the 1/4 watt: https://www.ebay.com/itm/32468305174...r=513856919460

[nomoresonys]

By size: https://www.youtube.com/watch?v=LRf33fN68ws

[Diah]

just to add.... if the PWM chip exploded .. must all SMD caps replaced beside the R on the TOP. its Frequency function should be captured by Oscillator, nozt only testing in R or Diode mode.

[nomoresonys]

Meant to say resistor in post #56, not diode.

[dinkodinko]

Hello,

I had few blown components on the LED power supply on BN44-00517C board, including 1kv capacitor, MOSFET, power resistor, and some SMD resistors for which I cannot find values, so maybe someone can help me.

I've tried to recreate resistor combination using a datasheet for the SSC2S110 pwm controller, but the LED backlight still won't turn on.
I can confirm that the LED backlight is working, pwm controller is working because I've soldered it instead of the same controller for logic power supply and that is working fine.
I've even changed the optocoupler.
The only thing that could have some influence is 0.22 ohm resistor RM811 i've put in instead of blown 0.24 ohm one, but it should at least start for a second, even if the resistor blows again.

Any suggestion is welcome.

Thank you in advance,


Regards,
Dinko