Samsung 2232BW - Please advise on proper capacitors

[mariushm]

So as I was saying on my first post, I got this Samsung 2232BW from eBay UK -the guy I bought it from said it just stopped working one day.

Sure enough, the blue power led turns on and then almost instantly fades a bit and remains like that, no image on screen.

Opened it up and pretty much all CapXon caps are bloated - just the big 100uF 450v and a couple of smaller ones don't seem bloated (but I think it would be better to just replace them as well with some proper ones).

Now I apologize in advance if this was already answered - I did search the forum but couldn't find anything specific.

Caps are:

C111: 820uf 25v CapXon GL 105c C729 - the three by the transformer (don't know where I could get the datasheet)

C113: 330uf 25v CapXon GL 105c P727 - the big one near CN2

C118: 22uf 50v CapXon GL 105c C727 - the small one near CN2

C107: 47uF 50v CapXon GL 105c P729 - by the transformer, on the side

C301,C302 : 820uf 25v CapXon GL 105c C729


Anything else that could potentially have to be replaced?
I don't think the big 100uF cap needs replacing, based on what I read on the forums here...
Should I test those transistors/ICs that are with heatsinks? If so, how? I can tell you the writing on them but it's very hard to read it as i write this.

I'm in Romania (funny enough this monitor is assembled in Romania) and here the best caps I can get are Samwa so i'd rather get from Farnell or Digikey and if I'll get from Digikey it's gonna take a while to get them so I'd rather get some parts even if I won't need them.
I think Moser wants me to pay 30 euro for shipping to send to Romania so it's out of the question.

If you want me to run some tests, I'm all for it - I have a digital multimeter and I have some basic electronics knowledge.

ps. The other pcb with the digital and vga input has only polymer caps - can't tell the brand, they're with a dark gray band and have V0807 written on them.

Thank you for helping me.

[mariushm]

Re: Samsung 2232BW - Please advise on proper capacitors

Ok, I found the CapXon GL datasheet:

So it looks like those 820uF are 10x25, ripple 1460, impedance 0.043

These should work then, right?

http://ro.farnell.com/panasonic/eeuf...0uf/dp/1800653
http://ro.farnell.com/panasonic/eeuf...0uf/dp/1744941

[PlainBill]

Re: Samsung 2232BW - Please advise on proper capacitors

Ok, I found the CapXon GL datasheet:

So it looks like those 820uF are 10x25, ripple 1460, impedance 0.043

These should work then, right?

http://ro.farnell.com/panasonic/eeuf...0uf/dp/1800653
http://ro.farnell.com/panasonic/eeuf...0uf/dp/1744941

Yes. But I'd go with the FR series (the first one).

PlainBill

[mariushm]

Re: Samsung 2232BW - Please advise on proper capacitors

Thanks...

Looks like I'll have to go with a mix of Panasonic FR, FM and Rubycon RX.

Here's the list, please let me know if something I chose looks bad.

5 x http://ro.farnell.com/jsp/search/pro...sp?sku=1800653 Panasonic FR 820uF@25v 10x20mm 105c 2180mA 0.02ohm - prev. was 10x25mm, 1460mA 0.043ohm
1 x http://ro.farnell.com/jsp/search/pro...sp?sku=1848387 Panasonic FM 330uF@25v 8x15mm 105c 1240mA 0.041ohm - prev. was 10x12.5mm 720mA 0.082ohm
1 x http://ro.farnell.com/jsp/search/pro...sp?sku=8127026 Rubycon RX 22uF@50v 8x11.5mm 130c 260mA 0.35ohm - prev. was 6.3x11mm 135mA 1.00ohm
1 x http://ro.farnell.com/jsp/search/pro...sp?sku=8127050 Rubycon RX 47uF@50v 8x11.5mm 130c 300mA 0.28ohm - prev. was 8x11.5 285mA 0.50ohm

Just the third cap is a bit bigger diameter wise but there is room on the board.. Should I (is it really worth it) maybe go for a 25v or a 35v capacitor if the ripple and impedance are still better than the old one, just for the sake of proper sizes? The capacitor is connected to the ground of the connector which feeds 13.5v to the board with the dvi and vga jacks and the processor.

Unless there's some objections, I'll place the order in a few hours or in the morning... it's 3 am here already. Thanks again, recapping is new to me and I want to get it right so I appreciate the feedback.

[PlainBill]

Re: Samsung 2232BW - Please advise on proper capacitors

Thanks...

Looks like I'll have to go with a mix of Panasonic FR, FM and Rubycon RX.

Here's the list, please let me know if something I chose looks bad.

5 x http://ro.farnell.com/jsp/search/pro...sp?sku=1800653 Panasonic FR 820uF@25v 10x20mm 105c 2180mA 0.02ohm - prev. was 10x25mm, 1460mA 0.043ohm
1 x http://ro.farnell.com/jsp/search/pro...sp?sku=1848387 Panasonic FM 330uF@25v 8x15mm 105c 1240mA 0.041ohm - prev. was 10x12.5mm 720mA 0.082ohm
1 x http://ro.farnell.com/jsp/search/pro...sp?sku=8127026 Rubycon RX 22uF@50v 8x11.5mm 130c 260mA 0.35ohm - prev. was 6.3x11mm 135mA 1.00ohm
1 x http://ro.farnell.com/jsp/search/pro...sp?sku=8127050 Rubycon RX 47uF@50v 8x11.5mm 130c 300mA 0.28ohm - prev. was 8x11.5 285mA 0.50ohm

Just the third cap is a bit bigger diameter wise but there is room on the board.. Should I (is it really worth it) maybe go for a 25v or a 35v capacitor if the ripple and impedance are still better than the old one, just for the sake of proper sizes? The capacitor is connected to the ground of the connector which feeds 13.5v to the board with the dvi and vga jacks and the processor.

Unless there's some objections, I'll place the order in a few hours or in the morning... it's 3 am here already. Thanks again, recapping is new to me and I want to get it right so I appreciate the feedback.

They all look good (although PCBONZ may disagree). My personal preference is to stick with the original voltage rating. If the power supply is operating properly, the caps will not be generating a significant amount of heat. (Just how many watts are dissipated by driving 2A through a .02 ohm resistance?)

PlainBill

(.08 watts)

[mariushm]

Re: Samsung 2232BW - Please advise on proper capacitors

Damn, UPS is fast.... placed order Wednesday at about 11pm, arrived to me today around 13.00

I can report a successful recap - pretty much the hardest thing was desoldering the existing caps, lead free solder sucks.

I've only tested the power supply outside the case, then mounted it inside and did a live test and the screen and everything work fine.

But I'm a bit concerned that while I tested the power supply outside unconnected to anything, the voltage going out through that connector was 11.9v instead of what's written there on the pcb, 13.5v.
I tested the set of three 820uf caps and the 330uF cap and the voltage on them was around 13.7v but the 22uF near it wasn't showing any voltage (one of it's legs is connected to ground on the connector so it could mean nothing, I don't know)

Do you guys think it's normal? The monitor did work fine for a couple of minutes while I had it on the desk (i already have two monitors on my system so there's no room to keep the third for a longer time).

I also have a spare set of caps - 5x820, 2x22, 2x47,2x330uF - they were cheap enough I thought it would be better to get reserves just in case I screw something up.
So if someone is in Europe and wants them, I can probably send them for around the shipping costs, 5-6 euro.

(if i'm not allowed to do this, I apologize, please edit my post and hope you understand I'm not trying to do any commerce here)

[PlainBill]

Re: Samsung 2232BW - Please advise on proper capacitors

The voltage for the inverter supply (13.5 in this case) normally will vary a lot.
First of all, they use a single SMPS to produce both 5V and 13.5 volts. Only one of the voltages can be regulated, by custom that is the 5V supply (usually 'juiced' up to 5.2 - 5.4 volts). That means the voltage on the 13.5 output varies, depending on the load on the 5V supply.

Next, usually we figure there is a 10% tolerance on any power supply. Of course, current technology can do much better than that.

Lastly, the inverter design itself is VERY tolerant of input voltage - as long as the supply is noise free. An inverter adjusts the output voltage to maintain a constant current through the CCFLs. If the input voltage is a little low, it just drives the transformers a little harder.

PlainBill