Re: samsung 226bw
OK,
I took the easy way out.
I replaced the logic board completely. so far, so good (so what (; ).
monitor is working fine at the moment.
I always suspected IC603 (lm393 - SMD version) but never got the chance to replace it and see if it solves the problem.
In any case, THANK YOU ALL for helping me, and please let me know if I can help anyone in any way.
yours ,
Liquias.
liquias
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Last Activity: 01-10-2022, 05:35 PM
Joined: 01-14-2012
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Re: samsung 226bw
This thread IS alive, as fa as I'm concerned.
I have some exams in the near future so I can't do much.
Please let me know if I can help....
Liquias.Leave a comment:
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Re: samsung 226bw
retiredcaps:
Thanks. I don't know how I missed this in the service manual. It does seem like this is the right description for IC204. I thought this section of the service manual (Electrical part list) is useless in my case, since schematics is not very accurate.
jetadm123:
I will take these measurements as soon as I can and I will update.
I did check for voltage change (while pressing the button) in the input of the op amp, and I think I did not see any. I will double check this when I take the voltages. I am sure though that...Leave a comment:
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Re: samsung 226bw
Yeah, I figured it must be something like that. It's nice to know you follow up on your threads even when they are only mentioned as reference...
But hey, maybe you have an idea what the mystery IC204 is ?
Its marked 6P and it's an SOT223-4 package.
I'm clueless.
anyone ???Last edited by liquias; 01-17-2012, 06:55 PM.Leave a comment:
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Re: samsung 226bw
Well thanks, I've actually read this post before I delved into the details of the problem I have, and so I didn't notice it was the same logic board.
I've also found this post :
[URL="https://www.badcaps.net/forum/showthread.php?t=17480&highlight=SAMSUNG+226BW"]https://www.badcaps.net/forum/showthread.php?t=17480&highlight=SAMSUNG+226BW[/URL]
In-which da.chisel seems to have the exact same problem I have, and retiredcaps suggests it may be a problem with the 3.3v regulator.
I double checked, the 3.3v...Leave a comment:
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Re: samsung 226bw
Well, I have to admit I haven't checked it specifically, but i'm sure its not, since if C709 was shorted I would find a short between the transistor's (Q601/Q700->SM) collector and emitter, and as I mentioned above the transistor is surely not shorted. Plus, I don't know which cap on the PCB is the one marked as C709 in the schematic (C611 or maybe C610 ??).
I am wondering though, in your opinion, is it safe to assume the problem is within the logic board ?
I would like to find the problem, and so I haven't given up yet, but if all else will...Last edited by liquias; 01-16-2012, 05:43 PM.Leave a comment:
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Re: samsung 226bw
Q601 is definitely not shorted.
I can trace the 0.465v back to pin 1 of the LM353 OpAmp IC (see schematic).
I suspect it might have something to do with the problem also.
Cable is seated OK, also it's not shorted or disconnected, I've double checked that.
I'm posting the schematic I found, but it's only close to the logic circuit (The general idea looks the same but parts are a little different and part numbering is way off).
Again, thank you!...Last edited by liquias; 01-16-2012, 02:08 PM.Leave a comment:
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Re: samsung 226bw
Hi,
On the PCB pin 9 is described as 'on/off' which makes sense as I fear this must be related with the problem.
The service manual describes pin 9 to be 'BL_EN' I'm guessing 'BackLight_Enable' ?
IC702 - 1501-50 Buck regulator for 5v gives 5.12v
Thanks !Last edited by liquias; 01-16-2012, 12:25 PM.Leave a comment:
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samsung 226bw
Hi,
This is my first post here.
First I'd like to thank the creators of this forum, and everyone involved in helping out. I think you are doing a wonderful job !
I am trying to troubleshoot a samsung syncmaster 226bw.
The monitor apears to be completely dead. no blue led, not 2 seconds to black, nothing.
I opened it up and looked for bloated caps on the power supply board. found 4 bloated caps. I decided to recap all electrolytic caps on the power supply board. nothing ! (no blue led , and I can't turn on the monitor).
I found a service manual...
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