Samsung 2253bw black screen

[Rtech]

Re: Samsung 2253bw black screen

So have you identified the Part Code ????

[e3gsr]

Re: Samsung 2253bw black screen

The 8-pin chips on the bottom side are Dual MOSFET's
"244.6 ohms
439.8k
0.1 ohms
5.4 ohms"
Are these the resistance reading that I asked to check by leave one probe on any one of the pins on the right side of the chip (pins on the right are connected together) as shown in my redlined picture, then another probe on each pin top read the resistance? If that's the case, then you have bad chip (shorted).
Can you read the numbers on them?

yes that is correct i thought one may be faulty given them readings. cant make it out clearly but my wife said it looks to her like etstm 8309.if i disconnect and remove the shorted one should the other one then work?

[Rtech]

Re: Samsung 2253bw black screen

Probably, but need both to work to get the Monitor back on,Part Code is a new one on me, perhaps budm may have some idea //You could try finding something like it on the Alldatasheet webpage

[budm]

Re: Samsung 2253bw black screen

They are dual MOSFET's setup as bridge drive so you will need both chips, there should be more than one lines on the chip, you may have to wet it to read the numbers.

[Rtech]

Re: Samsung 2253bw black screen

Got them STM8309
http://pdf1.alldatasheet.com/datashe...P/STM8309.html

[budm]

Re: Samsung 2253bw black screen

Great job ritech!
He should replace both of them.
See the typical setup fot this circuit.

[Rtech]

Re: Samsung 2253bw black screen

Looks like China stock them only based on UK Ebay, RS and Farnell do not.

[budm]

Re: Samsung 2253bw black screen

That is strange since ST Micro is European company, I would think they will be easy to get.

[Rtech]

Re: Samsung 2253bw black screen

Located in UK ;_
http://www.dalbani.co.uk/catalogue/p...s.php?id=35171

[selldoor]

Re: Samsung 2253bw black screen

That is strange since ST Micro is European company, I would think they will be easy to get.

I dont think the STM is ST Micro - datasheet says manufacturer is
Sam Hop Micro electronics corp

[Rtech]

Re: Samsung 2253bw black screen

Post 49 identifies them as Sam Hop

[budm]

Re: Samsung 2253bw black screen

I see, thanks.

[e3gsr]

Re: Samsung 2253bw black screen

wow you guys are awesome thank you very much for all your help so far. I will do a bit more work on this board and report back with the results.
Once again thank you very much for all your help you are all very kind.

[somem]

Re: Samsung 2253bw black screen

Please, can anyone tell me the c301 and c302 are 1000μf or 820μf?, also the same about c112, c118, c113 and c108, thangs to all

[selldoor]

Re: Samsung 2253bw black screen

Can you post a good clear straight down picture of the board & mark where they are if it is not obvious.

(max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Example of what is needed

https://www.badcaps.net/forum/attach...7&d=1280167246

[Sparks88]

Re: Samsung 2253bw black screen

I have brought up this thread because i have the same board but 2 secs to black, board recapped, mosfets all ok no shorts,all transformer solder joints reworked as well as a few others which looked suspect, i would like the schematic if at all possible my board is out of a 2233BW (LS22CMKKFV/EN), by the way there are 2 caps the wrong way round
C113 and C116.

[chstech]

Re: Samsung 2253bw black screen

I have read these posts about the Samsung 2253bw and hope some one can assist.
I have this monitor, and someone has started a repair - removed the caps, and I need to know which one is which for the locations shown as C301 & C302, C108, C113, C116, C112.

[lexwalker]

Re: Samsung 2253bw black screen

I have read these posts about the Samsung 2253bw and hope some one can assist.
I have this monitor, and someone has started a repair - removed the caps, and I need to know which one is which for the locations shown as C301 & C302, C108, C113, C116, C112.

What was the model and revision of that IP board? If its IP-49135B then these should be the usual values...

For C301, C302, C108 & C112 => 820uF 25V 105C
For C113 & C116 => 1000uF 16V

Markings may vary for different versions of the same board model. Trace the rails, anything that goes to the inverter side, usually +13V or more, should be using 25Vdc rated capacitors. For the other rail, usually +5V one, should be 16Vdc rated capacitors...

Generally for 820uF capacitors on the supply rail, I always never use the original values but rather replace them with 1000uF which have lower ESR, lasts longer (despite aging) and much cheaper (yes, believe it or not... those 1000uF are actually cheaper than 820uF ones!).

[BigDaddyAdy]

Re: Samsung 2253bw black screen

Hello, I have this invertor board IP-49135B.
At first, the monitor shut down suddently.
After opening it I found 4 bad caps. After replacing all caps, still nothing. I checked U202, U203, both shortened. I replaced them and now the monitor displays image for 2 seconds, after that it goes dark again.
It seems there is a problem with the OVP circuit.
Can you please tell me the values for R241, R214 and C207?
I have marked them on the image, in case i misread them.
On my board R241 is showing overheat marks and i can't read it. I measured it and it looks like 330K, which i don't think is good.
Also, c207 has a strange color, it looks more like an inductor then a cap, but on the board it is c207.

[selldoor]

Re: Samsung 2253bw black screen

Whilst the screen may be dark can you still see the image - it will be very dark and might just show if you shine a flashlight at different angles.