Re: Should I use flux when soldering in a new cap
I'm not an expert at all but heres my opinion:
The flux in the rosin core is typically very little (2.0% or less) and using own flux might make things easier and result in a better joint.
Flux (even the little flux inside the rosin core) should be cleaned carefully, i use 70% alcohol with q-tips and an old soft tooth brush.
Regarding trimming the leads, the leads should be trimmed before soldering, otherwise the force\movement of cutting the leads might crack the joint.
Just my 2 cents,
...
mastertheknife
Senior Member
Last Activity: 11-13-2023, 01:59 AM
Joined: 01-06-2011
Location: Israel
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Re: Replaced bulging caps, and pop... nothing
Also check this fuse, the live wire goes through this fuse before anything else.
Its probably blown, but without finding out the cause, it will probably blow again.
mastertheknife....Last edited by mastertheknife; 01-28-2011, 11:07 AM.Leave a comment:
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Re: Samsung SyncMaster 226BW
Thank you for the test. And yes, although i put ones that measured ~730uF. 6 out of the 8 measured ~450uF and the other two measured ~730uF, which are the ones i put in.
I will put new\old ones back when i receive the new fuses.
Thank you,
mastertheknife....Leave a comment:
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Re: Samsung SyncMaster 226BW
Hi, i circled the fuses in the attached picture.
mastertheknife...Leave a comment:
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Re: Samsung SyncMaster 226BW
Also, these Nichicon HD(M) 680uF 25V caps are all 10x16mm height, while the nichicon HD datasheet states 10x20mm for the 680uF 25V.
Is it likely that they are fakes, and perhaps they are the cause to the blown fuse? (They sit between positive from F301 and ground)
Also, this is what i received from the seller when i asked him about why these caps are 10x16mm instead of 10x20mm, this was his response:
"Yes these are HD(M) series.... Some case sizes are different but same Capacitance value. They change...Last edited by mastertheknife; 01-27-2011, 12:23 PM.Leave a comment:
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Re: Samsung SyncMaster 226BW
Good suggestion.
They don't seem to move, so i suspect the joints are okay. Also, none of the capacitors are shorted and resistance between F301 and ground is very high, so i'm not sure where things went wrong.
I will only be able to power up this board again in 2 weeks when the fuses arrive.
Thank you,
mastertheknife...Leave a comment:
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Re: Samsung SyncMaster 226BW
I took out the blown fuse. On the fuse there is only "3A E" on both sides.
From another thread, this seems to be a 3A 125V fast-acting(5s at 200%) fuse.
i will order some and hopefully it won't blow again. And if it does, i will try putting back the original capXcon 680uF caps to see if the problem comes from the new 680uF capacitors and i will report back.
Ideas, thoughts, theories, suggestions and anything else is welcome.
Seems like i have bad luck with those monitors or with electronics in general,...Leave a comment:
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Re: Samsung SyncMaster 226BW
I messed up again, not sure even how.
When fixing the "bad" 226BW i opened up my own 226BW (good) to compare readings on both boards.
After fixing the bad board, i closed the monitor and the monitor works like new, and still works.
But i noticed the good board had a plagued 330uF capacitor, so i figured i will order caps from ebay to replace all caps while the monitor is still open.
Unable to order from digikey or mouser due to expensive shipping ($30+ because first class is not available for international...Last edited by mastertheknife; 01-27-2011, 08:33 AM.Leave a comment:
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Re: Samsung SyncMaster 226BW
Hi retiredcaps,
I would have prefered replacing all caps, it sure would save re-opening the unit. Regarding the 47uF cap, i couldn't order from digikey so i had to order from ebay and what was i found was caps kit for the 226BW. In the pictures they are Nichicon PW (which they actually are, except the 47uF one and 330uF sadly and i did not know this until arrival).
I would order 47uF if i could, I have more than two 226BWs in my house and would love replacing the caps for all of them, but so far im unable to find low ESR 47uF 50V...Leave a comment:
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Re: Samsung SyncMaster 226BW
Hi everyone,
My cheap(works nicely though) capacitance meter from ebay arrived today. It arrived a little too late, because the board is already fixed. But why not test the old CrapXcon caps from the 226BW power supply board? I have compared some of the old capacitors to some new ones.
On the board (rev 0.1) there are: 1x330uF-25V, 2x680uF-25V, 2x820uF-25V, 1x47uF-50V, 1x450V cap.
Seems like the capacitors around the heatsink dried up or something, their capacitance is really low.
330uF (plagued): ~83uF...Last edited by mastertheknife; 01-24-2011, 02:18 PM.Leave a comment:
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Re: Samsung SyncMaster 226BW
pebe292:
I bought the repair kit on ebay for my brother's 226BW power board (Rev 0.1), the 330uF cap was nichicon VZ (which seems to be a general purpose cap) and the 680uF and 820uF caps were nichicon PW. the 47uF cap only had "CHNG" on it.
I am now replacing the caps on another 226BW of mine and this time ordering the caps separately from ebay. it might be more expensive than the kit but you end up with more capacitors.
330uF 25V Rubycon ZL caps (10mm dia, 12.5mm height): [url]http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360285748709&ssPageName=STRK:MEWAX:IT[/url]...Last edited by mastertheknife; 01-22-2011, 04:36 PM.Leave a comment:
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Re: Samsung Syncmaster 225BW
There are 2 revisions of the power board for the 226BW and other monitors who use that board (IP-45130A).
It says the revision on the board. Rev 0.1 has 1x330uF, 2x680uF and 2x820uF, Rev 0.2 has 3x330uF and 2x820uF.
mastertheknife...Leave a comment:
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Re: Samsung SyncMaster 226BW
Thank you both, its amazing how small was the problem and unnoticed for so long!
The monitor was powered on for about 10 hours now continuously with no problems, its like new.
Its unfortunate to see a reputable company like Samsung using low quality capacitors like those CrapXon caps in the 226BW's power supply board.
mastertheknifeLeave a comment:
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Re: Samsung SyncMaster 226BW
It works!!!!
With a better magnifying glass than i have, i noticed there is a solder ontop of a surface mounted capacitor. The multimeter confirmed a short, on the other board the two points measured 4.2Kohms.
After careful removal of the solder ontop with desoldering wick, i measured 4.2Kohms like on the good board.
I then put the board inside, plugged everything and fired up the monitor and it WORKS!!
I can't believe i didn't notice this earlier, must have been my poor vision.
Although i ordered new...Last edited by mastertheknife; 01-15-2011, 01:41 AM.Leave a comment:
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Re: Samsung SyncMaster 226BW
Is there a way i can bypass the OLP protection somehow temporarily just to be able to rule it out?
Would shorting pin 9 (feedback sense\OLP) with ground do it?
EDIT: No need, fixed the board, details and a picture in the next post
Thank you,
mastertheknifeLast edited by mastertheknife; 01-15-2011, 01:07 AM.Leave a comment:
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Re: Samsung SyncMaster 226BW
All caps are nichicon PW except the 330uF one which is a VZ series. According to the internet and the datasheet, the VZ series has higher ESR so i tried to put the old 330uF back but the problem persists.
After replacing caps again and testing other things such as the connections from the IC to the mosfets and from the mosfets to the transformers i am still unable to find anything.
Based on my measurements, i am almost sure the open lamp protection is what shuts off the inverter. According to the datasheet, max voltage for this...Leave a comment:
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Re: Samsung SyncMaster 226BW
I don't have the equipment to test that unfortunately.
mastertheknife....Leave a comment:
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Re: Samsung SyncMaster 226BW
I took out all capacitors to attempt testing them with the limited equipment i have (a simple multimeter).
I discharged each capacitor, then put the multimeter in 2M mode and attached the probes, the capacitors are not shorted and not open, and the resistance went above 2M so i don't think they are leaking either.Leave a comment:
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Re: Samsung SyncMaster 226BW
Here are close pictures of the inverter IC (OZ964GN).
I know the soldering looks terrible, its after reflowing the solder multiple times on everything out of desperation....Leave a comment:
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Re: Samsung SyncMaster 226BW
Yes, it seems the inverter area is multi-layered.
U301 seems to be a voltage regulator based on temperature. Part number:
KIA
431A
721
The datasheet can be seen here: [url]http://www.alldatasheet.com/datasheet-pdf/pdf/69358/KEC/KIA431A.html[/url]
Thank you,
mastertheknife.Re: Samsung SyncMaster 226BW<br /> ...IA<br /> 431A...Leave a comment:
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