samsung LN-S4051D diagnal lines

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

you have open R now at pfc... since it was clicking after u disconect MB from PCB.. like there are load / short at LED

did not understand this, you mean backlight led? this one is ccfl.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

it only clicked with mainboard connected, but now that the boosted pfc is gone there is no clicking every 5 seconds connected or not, like i had before with the boosted pfc.

[Diah]

Re: samsung LN-S4051D diagnal lines

you have open R now at pfc... since it was clicking after u disconect MB from PCB.. like there are load / short at LED

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

im checking all the tiny resistors caps n diodes, they're testing ok.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

any way of knowing what kind of ohms i should get on the legs of the pfc ic? or how to test it?

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

it must be the pfc ic is screwed, I lost my boosted voltage.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

oh I think i killed it a while ago lol, i don't know if i should be getting continuity on bridge+ and main cap+ theres a diode between them, of course i was looking at some work on a led tv, so probably different setup.

[Diah]

Re: samsung LN-S4051D diagnal lines

you dont think its time now to order new glasses ..lol
each time u work on tiny things you kill tv

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

no continuity between bridge+ and main cap+.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

seem to have a short somewhere that I can't find, dim bulb tester stays lit.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

ok, thanks Lotas, I'm glad those little buggers are alright.

[lotas]

Re: samsung LN-S4051D diagnal lines

found 2 tiny resistors on underside of powerboard 75r0 and 82r0 close to cni804 connector both read 39.5 ohms, think those could be causing these problems?

If these two resistors (75Om and 82Om) are connected in parallel, then you get just 39.2Om.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

found 2 tiny resistors on underside of powerboard 75r0 and 82r0 close to cni804 connector both read 39.5 ohms, think those could be causing these problems?

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

I think maybe icp801 is bad, it is the pfc controller: https://cdn.badcaps-static.com/pdfs/...43ef79150d.pdf

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

clicking 2 times every 5 seconds is gone again, think I either blew something while testing those ic voltages, which doesnt seem like it should have or maybe one of them is bad, maybe a resistor or a bad solder, not sure.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

no progress going in reverse lol, tried testing voltages with tv on, there's no backlight now, voltages at cnm 801 conector are right on and solid, had 381 0n main cap, was testing voltages on ics801, neg. of main cap for ground, when i touched pin 5 or 6 tv would go off and come back on, could tell by the samsung chime, pin 7 had 14.35, I think thats just a bit low, then was checking icp801 and while checking one of the pins tv went off. checked to see if main cap was still 381 but was only 165 in both stby and powered on, the led on optical out blinks once then is out, led on front behaves like it should solid red for stby and off when powered on.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

ok, I ran some leads out from the main filter cap, there's 171 in standby and 381 when powered on, no backlight and the relay clicking is back, clicks 2 times every 5 seconds.

[lotas]

Re: samsung LN-S4051D diagnal lines

The mosfet should not have low resistance between the drain and the source (if a diode and a zener diode are built into them), then a multimeter will show a working mosfet as you check a regular diode.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

Think I'm on the wrong path, just tested a couple more on a different powerboard, from a different brand and size tv, one was 176 ohms, the other was 90 ohms.

[lotas]

Re: samsung LN-S4051D diagnal lines

Well, if the mosfet has broken, you need to check all nearby components for breaks and short circuits (resistors, diodes, zener diodes ...). After that, you can install a new mosfet.