samsung LN-S4051D diagnal lines

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

also no continuity to ground on very small caps on underside CI811, CI835.

How is THIS even possible, I don't get it?

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

only pins showing continuity on the ic itself is pin 4 to 5.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

mosfet QI802 which was shorted gate to source and replaced, shows continuity/short from source to pin 4 and 5 of ICI804 above. gate to pin 5 also shows continuity/short.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

can I test this IC in circuit using ohm mode or diode mode? https://datasheetspdf.com/pdf/560565...ctor/FAN7382/1

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

also no continuity to ground on very small caps on underside CI811, CI835.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

very small cap on underside CI839, shows no continuity to ground.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

ts801 shows 3.1 ohms from one of the corner pins to the one next to it, too high?

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

so checking the optos, most give a reading on one side, meter in diode mode, like if say pin one and 2 where the legs are side by side, get a reading with probes on each, swicth probes no reading, other end the same but there's one right beside another that gives no reading on one end probes reversed or not, so tested another boards optos and some do the same thing. opto in question is pcm802, pcm801 right beside it gives reading one way on both ends as do the other 3 on the board.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

have 3 resistors in parallel, 2.2 ohm, 22 ohm and 10k ohm, 2.2 and 22 are right on, the 10k is only 40 ohms, is that ok??

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

will AR S1 80 diode replace 1n4005? they are same size physically, can not seem to find info on ar s1 80.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

took out ds805, testing the thru holes I only get 59 ohms, is that too low?

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

CNI804 does have 12 volts as indicated at the connector.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

yes, I was getting the bad cap clicking syndrome, changed those 8 electros out and it worked fine for several months then the connector from powerboard to main burnt out, think it was just from old age, replaced that and touched up the joints worked fine for a few more months. Started clicking again, could get it to stop and the backlights would be on for 15 minutes or so by heating the area of ICS801, then was messing around testing the three 8 pin ics on top side of board while powered while testing one of them tv went on and off, then tested main cap and saw I lost the boosted pfc, found QI802 shorted from gate to source, switched it out with K4087 https://www.alldatasheet.com/view.js...K4087&sField=1, which I think is close but not sure. Now still have no boosted pfc and heating that area of ICS801 doesn't get the backlights to come on anymore.

[vinceroger69]

Re: samsung LN-S4051D diagnal lines

well this one crapped out again, getting the clicking of the relay every 5 seconds, fixed it once with electro caps replacement and reflow of solder joints, lasted a few months now its back same thing, clicks every 5 seconds. When powerboard is unhooked from mainboard clicking stops but backlights don't come on, when heating area of ics801 for a minute or two tv comes on for 15 minutes or so no clicking, replaced or checked all caps and resistors in that area, anyone know if heating ics801 is making it work for that 15 minutes or should heating it have no effect on the ic as in letting the tv work for that 15 minutes??: sj pic of powerboard: https://www.shopjimmy.com/samsung-bn...ight-inverter/

just been reading this thread on the shop jimmy picture top right where someone has marked those capacitors with red marker have you tested all of those caps in that area for uf and esr as these do fail maybe heating that ic is also heating these caps and lowering the esr tempory

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

the samsung I'm using in place of this one is a un model edge lit tv and it pales in comparison no matter how much calibration is done, much lighter and sleeker looking and no mercury BUT worse picture quality.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

Lol, that would point to insanity wouldn't it? no, I fixed it with a mainboard in early 215 then it just started acting up again lately, its old as dirt but these early samsungs have a very good picture, otherwise I wouldnt bother with it, kind of heavy and clunky compared to newer stuff. I like the puzzle aspect of it but so far its getting the better of me.

[angelos]

Re: samsung LN-S4051D diagnal lines

Wow Nomoresonys you surely have perseverance. You started this thread in 2014 and you are still at it. I know nobody out there that would do that. Cudos to you.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

ok, now have the clicking twice every 5 seconds back, gonna call that progress.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

can it be just a weak faulty bridge? all the diodes check good in it.

[nomoresonys]

Re: samsung LN-S4051D diagnal lines

can anyone answer the question, why the dc voltage on the bridge rectifier, thats + and - the 2 outside legs is 106, it was 106 when the backlight was staying on for 15 minutes, the ac coming in on the bridge rec. is 120 as it should be, is this normal or does it point to a problem???