Re: Samsung 242mp PSU problem
@pe9ghz check your mainboard.... My only advice.
I still have no clue of whats gooing on with my beast, resoldered some part of main without any luck, but i did discover that putting a small plastic washer under pcb upper right screw of main pcb (PSU at my right) did make the thing work, removing the washer and it does not work. So been using this for 3days with a little washer about 1,5 - 2mm thick, plugged in/out 30 times tapping a little here and there to stress the symptoms but no it still works. Not a permanent fix but this will...
Jont3
Member
Last Activity: 03-23-2024, 05:11 PM
Joined: 01-31-2012
Location: Sweden
-
-
Re: Samsung 242mp PSU problem
You really got the eagles eyes, thats a really good thing i think. This is a revision diff, but thanks!...Leave a comment:
-
Re: Samsung 242mp PSU problem
I checked all markings as i removed the old ones and they where correct, and i do have pics of it before so i can check if i would wounder. And no, in a PSU they will not often pop since there is not enough current for that, more like get varm and vent over time how fast depends on multiple factors still, a pop could happen
.
Anyways, me thinking PSU was not right. Spent a whole weeks sparetime to check this PSU/chips/diodes etc with your guys help and the PSU is fully functional! Tripped over to the mainboard/signal...Last edited by Jont3; 02-05-2012, 03:18 PM.Leave a comment:
-
Re: Samsung 242mp PSU problem
Naah, mine is right. The darker half circle on pcb i minus. Ooh yeah.... They pop and smoke...
Leave a comment:
-
Re: Samsung 242mp PSU problem
As i'am digging myself deeper into the psu, beginning to think that it might be non faulty, i look at the signal board.... Never realized that it contain so many SMD electolytic caps, talking 50-60 caps. Varying from 100uf/35v and down to 4,7uf/16v. So trying to jumpstart this with on/off lead from signal board (in non working state) i get the 24v part going. Thinking about changing some of them to start with, since shorting 1st 35v/100uf cap on signal board actuallty makes it power up.... Atleast those three times i tryed... Any suggestions? Not going...Leave a comment:
-
Re: Samsung 242mp PSU problem
Yes! but still thinks mine is functional.....
Okay, this is what i found so far.
When lcd working:
It start out with a DM0365R getting 380V on PIN-5 |PIN-2 14V, |PIN-3 0,4V |using pin1 as gnd.
Then we have a DM0565R witch reads |PIN-4 9,3V |PIN-3 14,5V |PIN 5-6 NC |using PIN-2 as gnd.
And the NCP1230 chip as posted before
Not working:
DM0365R: PIN-5 301V |PIN-2 14V |PIN-3 0,4V
DM0565R, NCP1230 is just zero volts.
I´am still in looking...Last edited by Jont3; 02-04-2012, 06:01 PM.Leave a comment:
-
Re: Samsung 242mp PSU problem
Been checking this board today and belive that this NCP1230 chip is not faulty. As i see this nothing will happen unless the opto-couplers are "on" and they are "off" when not working, optocouplers are driven by the 5V source that allways seems to work fine. This puts us in the cold part of the board and there are a couple of small TO-92 shunt regulators KA431AZ (US802 specially, resting against heatsink) ment to drain/source the leds in optocouplers (?). "way of the line" or could this be something? comments please
...
Last edited by Jont3; 02-04-2012, 09:26 AM.Leave a comment:
-
Re: Samsung 242mp PSU problem
I´ve like tripple checked this since i posted the pictures, and did so again. it should be ok, and "beeping" (at right places) when tracing on board with DMM. There is no short its just flux and removed now.
Lcd been unplugged over night when measuring, 450V cap 0,0V, No "beep" between pin 8 and 450V positive leg. Pin 1 & 8 does not have any trace on board (see picture). There is no wire trough board from "chip side" related to pin 1&8, since chip is located...Leave a comment:
-
Re: Gateway FPD2485W | 2 second to Dark
Well, you would have to open up the monitor. This could be multiple faults, checking overall condition (defects, burns etc) and seaching for bulgy caps on the power and inverter board is the first step.Leave a comment:
-
Re: Gateway FPD2485W | 2 second to Dark
I´am not sure if i understand you right here, when monitor starts backlight goes off and everything else seems normal? if so, and you put an heavy amount of light on the screen do you see the desktop/boot up?Leave a comment:
-
Re: Gateway FPD2485W | 2 second to Dark
When the lcd goes black, is the panel still active? try a flashlight or such in front of panel.
As in backlight still on?...Last edited by Jont3; 02-03-2012, 04:25 PM.Leave a comment:
-
Re: Samsung 242mp PSU problem
I would like to see the p/n number & revision ver to, since "mine" seems to be somewhat older and they could differ. I mailed samsung trying to get a schema for it, was redirected to convena who said there is no such avalibe, could order a spare from them but that isn´t all that fun, is it? :P...Leave a comment:
-
Re: Samsung 242mp PSU problem
Maybe i should be more clear as the CP822 & CP826 read 0V when not working.Leave a comment:
-
Re: Samsung 242mp PSU problem
Not working:
8-4 0V, 6-4 0V, 1-4 0V
Working:
8-4 0V, 6-4 14,5V, 1-4 14,5V
It seems like pin 1 and 8 is not connected anywhere on the board, can it be another config than the one in figure 29? cap closest to pin 6 is 10uf/50V there is also a 22uf/50V neaby but it is not to be called starting cap, both with the same steady 14.5V (CP822 & CP826) i even checked the old caps for values, and this is the original vaules nothing beyond 22uf/50V is on the board. Also tried the wooden stick with...Leave a comment:
-
Re: Samsung 242mp PSU problem
Checked startup cap, would be the new 10uf/50V reading steady 14.5V at function of display. Also checked voltage at all four optocouplers reading 1.3Vx4 (on led side that is) thinking if they are not "on" there will not be any voltage at NCP1230 either. pulled the cord before checking pin6 witch was a little mistake, 14.5V seems as too much here.
Anyways at non fuction i read zero at startup cap, three of the optocouplers are zero and one 4V (PC102S) may be of less importance but i still did this so. Popped up...Last edited by Jont3; 02-02-2012, 05:27 PM.Leave a comment:
-
Re: Samsung 242mp PSU problem
Will check NCP1230 circuit and cap, i did change all caps totally 17 new and a fresher big one. All suncon except for one elna low esr 10uf/50V i really do not think caps are the problem anymore. Thanks for your kind words and Help so far[URL="https://www1.elfa.se/data1/wwwroot/assets/datasheets/06719173.pdf"]https://www1.elfa.se/data1/wwwroot/assets/datasheets/06719173.pdf[/URL]Re: Samsung 242mp PSU problem
Will check NCP1230 circuit and cap, i did change all caps totally 17 new and a fresher...Last edited by Jont3; 02-02-2012, 01:49 AM.Leave a comment:
-
Re: Samsung 242mp PSU problem
Everything here has PFC.... probably law for new products.
Elfa is a big company, would be safe then.
Done some measuring on the bridge rectifier as follows:
100% function:
with lcd on connected to computer via dvi 244V
in standby mode 311V
No function:
309V
This time it was even more random plugged it in and out for about 7 times before it died, 8th time dead... 9th time 100% functional, 10th time dead, 10minutes later 100% functional.
Also noticed...Last edited by Jont3; 02-01-2012, 02:18 PM.Leave a comment:
-
Re: Samsung 242mp PSU problem
Ok, but wouldn´t that cause a more permanent problem? as it actually works if left unplugged for a while.... will check anyhow.
Bought the caps from [url]www.elfa.se[/url], so i really hope that they are originals. Hopefully i will be able to post better/bigger photos tonight ala macro.Re: Samsung 242mp PSU problem<br /> ...<br /> <br />...Leave a comment:
-
Re: Samsung 242mp PSU problem
Some joints look "cold" but i belive it is the original "solder wire" charactheristics, they have been reheated by me....Leave a comment:
-
Re: Samsung 242mp PSU problem
Yes i can fix a underside pic tomorrow. Actually i changed the 450/150uf with one taken from a samsung 32" as it is a little stupid place to put a cap on, lots of heat there.... But same readings with both caps so there is something else messing it up. don´t know what make it is as typing, check tomorrow....Leave a comment:
No activity results to display
Leave a comment: