Re: Samsung 2493HM - Blinking Power LED Problem
[CENTER][B][U]MONITOR FIXED[/U][/B][/CENTER]
The monitor is finally fixed, what was the cause of the 21V on 24V line problem was the transformer that's driving the 2 main MOSFETS, it had a broken pin(pic below), i bodged it, cleaned the board a bit, and it worked like new. So again, from start to finish to what was wrong, the standby power LED was blinking, i wasn't getting any voltages at all(5.4V/21V), i tested the VCC and GND of the MC33067 IC, and they where shorted, replaced it, and got my standby power LED fixed,...
SoDown
Member
Last Activity: 04-18-2023, 03:21 PM
Joined: 08-23-2019
Location: Belgrade
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Re: Samsung 2493HM - Blinking Power LED Problem
Forgot to mention that i'm getting a picture on the screen, but the backlight keeps flickering, so the problem is either in the inverter itself or maybe the power supply board. I have no way to test the CCFL's, so can't really tell if it's them.As for the inverter, i'll try to get my hands on a <14W CFL lamp and test it like that(I have a 30W one now). Also, anyone got a schematic for the inverter board(BN44-00136B)? Would help me a lot knowing where what is connected, thanks
. Pics of the inverter board included below...
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Re: Samsung 2493HM - Blinking Power LED Problem
Did some measuring, and here's the results: PS_ON is 3.2V, S_B is 5.24, 5.3V line is present with 5.4V on it, 24V line is present sometimes with 21V on it, i also hear some crackling while it's on, i previously didn't hear that. Any clues on what might crackling, also any clues as to why i'm not getting 21V on the 24V line ? Thanks....Leave a comment:
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Re: Samsung 2493HM - Blinking Power LED Problem
Sorry for long period of silence, i was waiting for the IC(MC33067) to arrive from China. Once it did, i replaced the old one, connected everything together and solved the old problem, which was blinking Power LED, now it doesn't blink anymore. But now a new problem, once i try to power it on, the backlight starts flickering like crazy, i measured 21V on the 24V line to the inverted, didn't measure rest of the voltages yet, will do that later and update this post with them.
I also compared the old IC with the new one,...Leave a comment:
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Re: Samsung 2493HM - Blinking Power LED Problem
Ok, some updates. I removed the 2 diodes in question(DM801/DM802), and the 1 SMD cap(Pin 12), tested them with the ESR tester, and they're fine, i think(pic below). I also took some time to remove the QM802 and QM803, tested them and they also look fine, removed the CM808 Cap, and the TM801(one side, pic below) as well.Now, since i removed the 2 diodes and the rest i tested for shorts, and i'll mark them in the pic below. Correct me if i did something wrong, thanks.
Edit: What i meant with "1 Probe here" is that...Last edited by SoDown; 08-29-2019, 07:06 PM.Leave a comment:
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Re: Samsung 2493HM - Blinking Power LED Problem
Did just that, forced it on with a 1k Ohm resistor, and i still got no voltage on 24/18/5.3V ones, what i did find out tho is that 2 diodes near ICM801 are shorted and so is one SMD capacitor near the IC, also, i tested between VCC and GND of the IC and got near 0 (Watched some YT video where a guy said to test it, and if it's near 0 then it's dead). So what i'll be doing is ordering a new IC(MC33067P) which will take a while to get to me and in the mean time testing all of the transistors/diodes/etc. The picture below shows about...Leave a comment:
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Re: Samsung 2493HM - Blinking Power LED Problem
Unfortunately i don't have a bench power supply, maybe i can hook some 5V(or lower) charger that i have laying around? Also i ordered a cheap component tester, so i plan on taking capacitors and resistors/diodes/etc off and testing them one by one....Leave a comment:
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Re: Samsung 2493HM - Blinking Power LED Problem
Checked QM802(QM801 on scheme), desoldered it, measured it using multimeter as i don't have any proper equipment, and it looks fine, as for QM803(QM802), i couldn't desoldered it as it was in a tight spot, maybe i'll try it later again. What i did do is clean some more brown glue on TM801(TM802) and the cap near it. As for the Inverter, i didn't connect it, i just measured the voltage on the Power Supply Board connector and so far it's 0V.
Also i replaced RX801S because it smelled like it was burnt, and once...Leave a comment:
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Re: Samsung 2493HM - Blinking Power LED Problem
Nope, i get some small voltage on PS_ON (0.3-0.01 keeps changing) on it....Leave a comment:
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Samsung 2493HM - Blinking Power LED Problem
Let me start off by saying that i know that there already exits a thread with a name similar to this one, but the guy in that thread didn't reply if it was fixed or not, so i'm starting a new one, feel free to merge them if necessary.
With that out of the way, my board models are:
Power Supply: BN44-00195A
Main board: BN41-00962A
What did i do:
I replaced 2 resistors RM801 0.22 and RX801S 750K using schematics i downloaded, removed almost all of the brown glue on high voltage parts, checked voltage on Power_EN which was 0~0.3, and S_B which is... -
Re: New Members - please post your introductions here
Hello, i'm new here. I hope we get along.
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