Samsung 2253LW

[ab101]

Hi,

I have a Samsung 2253LW that's been going strong for 3.5 years but the last few days randomly decides if it's going to work or not (sometimes pulling the plug out and sticking it back in will fix it, other times not).

Ive got it in pieces right now and can identify 2 bulging capacitors, both are Sam Young 25v 820uf 105 degrees - I thought it would be a straight swap but having searched the forums it looks like there are a lot of capacitors that match that description!

Could someone tell me exactly which one I need, and who in the UK sells them (trying to avoid high minimum order values but there is a maplins near me)

Thanks in advance.

[budm]

Re: Samsung 2253LW

I would suggest you to use PANASONIC FM or FR series for the replacement. You should repalce the whole set of caps in the secondary side of the power supply at least.
http://search.digikey.com/us/en/cat/...panasonic%20FM
Post the pictures of the board.

[tom66]

Re: Samsung 2253LW

Hi,

I have a Samsung 2253LW that's been going strong for 3.5 years but the last few days randomly decides if it's going to work or not (sometimes pulling the plug out and sticking it back in will fix it, other times not).

Ive got it in pieces right now and can identify 2 bulging capacitors, both are Sam Young 25v 820uf 105 degrees - I thought it would be a straight swap but having searched the forums it looks like there are a lot of capacitors that match that description!

Could someone tell me exactly which one I need, and who in the UK sells them (trying to avoid high minimum order values but there is a maplins near me)

Thanks in advance.

Maplin don't sell low ESR caps, just junk caps. Farnell and Mouser are good. Some eBay sources are good, if from the UK, but avoid sources from China, as the capacitors are very likely counterfeit.

[ab101]

Re: Samsung 2253LW

I stupidly didn't take a pic of the whole board - I had to reassemble the monitor due to space. (phone quality) pic of capacitors attached.

[ab101]

Re: Samsung 2253LW

I would suggest you to use PANASONIC FM or FR series for the replacement. You should repalce the whole set of caps in the secondary side of the power supply at least.
http://search.digikey.com/us/en/cat/...panasonic%20FM
Post the pictures of the board.

So something like this?

http://uk.mouser.com/ProductDetail/P...dGnQq2YR4mM%3d

Thanks

[tom66]

Re: Samsung 2253LW

Those look perfect.

[ab101]

Re: Samsung 2253LW

£12 delivery! ouch...

do these look ok?

http://www.ebay.co.uk/itm/25V-820uF-...item1c18f73fcd

sorry - bit of a noob at this!

[tom66]

Re: Samsung 2253LW

They look okay. They are probably FC, but those can still be used. (Just not as good as FM or FR; those are gold print.)

[ab101]

Re: Samsung 2253LW

are the rubycon better?

http://www.ebay.co.uk/itm/Rubycon-82...item4ab461465a

thanks again!

[ab101]

Re: Samsung 2253LW

After swapping the 2 820uf 25v I still got nothing and realised the 47uf 50v cap had also blown - just swapped this out for a new one and now when I plug the monitor in the blue light slowly flashes and I hear a high pitched whistling noise - the back-lights don't come on however and I don't see anything on the screen.

All other caps look OK - is there any more I can do or is this thing dead?

[selldoor]

Re: Samsung 2253LW

Hi - what make cap did you use for the small one - If that is on the primary side it is probably the startup cap so a decent brand/series is essential.

With it all connected up and powered on what are the voltage readings on the connector out. Cant see the board markings -looks like 12 pins
List them e.g.
1 12v actual 12.3
2 5v actual 4.7
3 gnd
4 dim etc etc

To be honest there are so few caps on this board you should have replaced all of them to give it the best chance

[ab101]

Re: Samsung 2253LW

I've lost my multimeter so cant check.

all caps are Panasonic FC.

The start-up cap seems to have definitley worked as I didn't get blue light at all before.

Caps not replaced:

Far side:
2x 820uf 25v
1x 16v 100uf

Inverter side:
2x 16v 1000uf
1x 50v 10uf
1x 10v 33uf
the massive cap - think its a 100uf 450v but the label is against the PCB and dont want to move it really.

everything looks OK, no bulging or puffing. all original caps look to be Sam Young.

[ab101]

Re: Samsung 2253LW

board markings are

B-DIM
13.0v
GND
GND
5.1V
5.1V
A-DIM
on/off
3.3v
LED
KEY1
KEY2

[selldoor]

Re: Samsung 2253LW

Sam young caps do not have a great reputation.
Without a meter it is pointless to continue £3 on ebay - not brilliant but
would suffice for a one off job. ( Been using my similar for years)
http://www.ebay.co.uk/itm/Digital-Vo...item3a73e80494

You cannot tell how good caps are by looking.

These caps are all same make , a similar age, in a similar situation. How long do you think before they need replacing? - Ignore the big one - its situation is a bit different.

Cheesy analogy - Buy 6 packs of cheese at the same time, same use by date (two weeks ago) all kept in same place in fridge you notice one has gone off. The other five LOOK ok - How long for? eat it - I dont think so.

[ab101]

Re: Samsung 2253LW

OK going to try and replace all other caps except the big one - will report back.

thanks for the help!

[jahjhai]

Re: Samsung 2253LW

ab101 what was your conclusion and findings? were you able to fix the problem,. i got the same problem that is why im asking about this problem.. if your able to fix it it would be of great help... thanks in advance..

[budm]

Re: Samsung 2253LW

@JAHJHAI: Does your board have bad caps as shown by ab101?

[jahjhai]

Re: Samsung 2253LW

yup i just did replaced the 820uF/25V caps near the output area for the ccfl, high pitch noise is heard and tested some components, problem is the green fuse resistor has no continuity using the tester with beep continuity.. trying to find out if the mbr20100ct is bad, led indicates power which is the blue led. almost the same problem with ab101

[jahjhai]

Re: Samsung 2253LW

best thing is provide some test points were in i can compare the voltage data for each critical components.. one of my observation is that the 13.0V gives me 16V which is for the LCD video controller area. im not sure if there is problem on that part. tomorrow i'll do a lot of testing and check the flow of each voltage pathway..

and oh by the way I used 1000uF/25V since its hard to find 820uF here.. will that hurt the power supply??

[jahjhai]

Re: Samsung 2253LW

yes the same problem..

did check some critical components... like the fuse resistor which i believe is open since there is no continuity.

i did replace the caps also same problem with ab101