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I've read the HELP CENTER > ASKING page. Not sure where I stepped out of bounds in the original post, but I've reduced the content to the following in an effort to comply:

At issue is the IP (Initial Power) board of a Samsung LCD computer monitor. See picture. The three large capacitors in a row have domed tops and the one at right shows a bit of tan/brown crud in the quadrant lines.

The resilient glop that covers the three compromised capacitors (GLYPTAL?) is removable (but not entirely) by slicing with an X-acto knife and yanking with tweezers.

The 3 large caps appear to be three of the same, but I can't remove enough white stuff to read and know for sure... The one I can read says "820uF25V" Any advice on whether they're identical would be much appreciated. They measure approx 10mm D x 20mm H with lead spacing of approx 5mm (Olin's excellent suggestion was too tall at 25mm).

I have no way to TEST the board and I fear there may be other issues beyond the three apparently compromised capacitors.

In light of that, should I replace the board, or will replacing the three caps likely solve the problem? FWIW, I did accidentally bend (and subsequently straighten) some of the longer leads of surrounding components while removing goop. So I'm concerned that I may have loosened some other component(s) in the process...

Thanks, and MANY thanks to Olin for the outstanding, helpful post. Tom

PS. If the post if off-topic for the TAG 'Solder' I tried multiple times to find a more suitable tag, but was told repeatedly that I don't have ample standing...

Resilient Goo (GLYPTAL?)

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    \$\begingroup\$ You don't really have to replace it. I pick at it with my fingers or use a knife usually. Good luck in your repair! \$\endgroup\$
    – HL-SDK
    Commented Dec 11, 2013 at 19:10
  • \$\begingroup\$ possible duplicate of Whats this white stuff on my board? \$\endgroup\$
    – Nick Alexeev
    Commented Dec 11, 2013 at 19:13
  • \$\begingroup\$ Try to replace the caps. If you fail, order a new one. All you need is a high watt iron. \$\endgroup\$
    – Passerby
    Commented Dec 11, 2013 at 19:25
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    \$\begingroup\$ Since the caps are gone and you don't care about them, you can slit the plastic sleeve in order to remove the bulk of the cap from the glue, and then cut the sleeves out after. \$\endgroup\$
    – Ignacio Vazquez-Abrams
    Commented Dec 11, 2013 at 20:30
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    \$\begingroup\$ @user34002 Also don't use C(r)apXon capacitors as a replacement. They are used there for a reason and you just found out what that reason is. \$\endgroup\$
    – AndrejaKo
    Commented Dec 11, 2013 at 20:33

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The goo should have some give. You should be able to scrape away enough of it with a exacto knife or small screw driver to allow you to remove the three caps. Yes, they look in pretty bad shape. You are lucky in that you caught them before they blew. That would be a much bigger mess to clean up, probably not being worth it.

These caps are obviously a weak link in the design. Either the designer cut corners and the caps are overstressed, or they cut corners and bought sub-standard parts. The cap brand "CapXon" seems suspicious to me. I'd never use a off-brand for caps like that in a commercial product I sell. Either way, I'd replace them with caps of a little higher voltage rating. These seem to be 820 µF 25 V caps from the picture, so I'd replace them with at least 30 V caps. Keep the capacitance the same though.

My normal place for getting such parts is Mouser. For example, this part looks like it would do. Panasonic is a trustworthy manufacturer, and Mouser is a trustworthy supplier. This is NOT the kind of item you want to buy on Ebay, since fraud is hard to detect.

These replacement parts might not fit exactly the same way mechanically. But this is a one-off manual job, so you can ben the leads a bit as needed to get the leads of all three caps thru the holes, then glob some hot glue around the base to hold everything together. I would NOT go nuts with the hot glue and surround the main body of the caps as shown in your picture. That would insulate them thermally, which is not good for them. That may have contributed to the failure of the original caps.

Another important thing to do is to note which manufacturer produces this mess in the first place. These caps really shouldn't be failing like this, and it's hard to see how it's not Samsung's fault. The CapXon caps are probably substandard or just barely to spec, but it was Samsung who, probably quite deliberately, used el-cheapo parts in this case. Be weary of other things from this manufacturer, now that you know they cut corners figuring things will break after the warranty period and clearly don't care much about their reputation.

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I would buy the board just to have a back for future problems. But I would attempt a cap replacement first. Also, I would get a higher (50V-100V) rating caps as those ones proved to failed.

The glow stuff can be removed if you use a hot air gun and tweezers. I bet that using a soldering iron can work your way through the glow.

Also, "gearing up" for this time will save you time and money in the future. It is a well worth investment.

-Good luck

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  • \$\begingroup\$ No, I would not use a hot air gun. That could heat some other components too much. \$\endgroup\$
    – Olin Lathrop
    Commented Dec 11, 2013 at 21:49

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