caps?

[spottydog10]

Hi everyone, nice to be here.

I have a problem with a DGM L-2362WD lcd monitor. (3-4 years old)
The last few weeks it's been reluctant to start and the last few days it's took a full 5 mins , but today all I'm getting is a clicking sound, no picture and the power light is not on. There is a slow dull flicker on the screen but barely discernible. I've changed the power cable.
Am I right in thinking this is faulty capacitors?
If so, where do I get replacements from?
I'm going to disassemble it tomorrow and see if they look blown.

Thanks for any help,

Mike

[budm]

Re: caps?

We will wait until we see good clear pictures of the boards first.

[spottydog10]

Re: caps?

Hi budm,

Exactly what pictures are required?
Thanks,
Mike

[budm]

Re: caps?

Pictures of the circuit boards, the whole back side of the monitor so we can see all the boards and how they are all connected together.

[spottydog10]

Re: caps?

Bud, here's the pics as requested.
Let me know if I've shot what you need.

Thanks,
Mike

[budm]

Re: caps?

OK, we need the top side (component side) picture of that large board on the right which is the power supply-inverter combo board where most of the bad caps will be if it does have bad caps.

[jdmillard]

Re: caps?

Bud (budm) is just saying that there are more capacitors on the other side of that board (the one on the right side). Take out those mounting screws, flip over the board, and send us a solid image.

Bud is the expert here, I'm just trying to feel special by contributing.

[spottydog10]

Re: caps?

Hi Bud,
Here they are.
Thanks,
Mike

[spottydog10]

Re: caps?

I missed the big cap, here it is.
Mike

[budm]

Re: caps?

I see at least 3 small bad caps (red circles) with domed tops, the big one (450VDC) looks like it has domed top also (may be the reflection?).
You should replace the caps as a set (I marked them beside the red ones).
I used PANASONIC FM/FR/ or FC series for the small caps (LOW ESR type), the large one will have to find the size and ripple current rating that will fit the board.

[mariushm]

Re: caps?

Big capacitor is OK looks ok to me but now that budm mentions it, you may want to change it as well.

The five capacitors by the heatsink and cable in the last picture in previous post should be replaced. Same for the one in the center of the board which feeds the inverters (the lamps). Only three show signs of going bad, but if these are going bad, the others are not far behind.

Since you're in UK , Farnell or CPC (farnell shop) would be a good choice :

http://cpc.farnell.com/aluminium-ele...etResults=true

http://uk.farnell.com/aluminium-elec...acitors-leaded (this version of farnell site may charge a higher shipping fee or require minimum purchase)

From the CPC site, Panasonic FM or FR or Rubycon ZL are great choices for replacement.
From uk.farnell, you can also get united chemi con kze, lxy, lxz

Choose same capacitance but feel free to choose capacitors with slightly higher voltage rating as long as you can fit them on the board (look at diameter and height.. you kinda have room diameter wise)

[spottydog10]

Re: caps?

Thanks guys, this very helpful.
I've never replaced any caps before.
Have I correctly identified the large cap replacement?(see pic)
The smaller ones could someone point me to the correct replacements thanks.

Any safety issues when doing the actual job or any other tips?

Thanks,
Mike

[mariushm]

Re: caps?

That capacitor is not good. It's only 2.2 uF , the pictures often don't match the actual product on Farnell's sites.

You need 100uF 400v (or higher). You may be able to go a bit lower or capacitance, or a bit higher.

The only one anywhere close to what you need on CPC is this one (it's actually perfect match when it comes to uF value and voltage) : http://cpc.farnell.com/panasonic/eca...00v/dp/CA07315
Unfortunately, you'd have to order 5 of them, it's minimum order.. so it's not worth it.

uk.farnell.com has lots of options but like I said, they have minimum order if i remember correctly.

I'd suggest leaving it like that... the large capacitor isn't subjected to a lot of stress, it's only affected by the heat inside the monitor. It should last for a bit longer time until you find something suitable.

[momaka]

Re: caps?

The big 400V cap is clearly bulged and needs to be replaced.
I have seen far too many CapXon primary caps go bad to let one go. Sometimes they even go completely open circuit.

You can also use this one:
http://cpc.farnell.com/panasonic/eco...fit/dp/CA04874
...but you will need to solder leads to it (20-24 AWG solid core wire works well) in order to make it sit sideways like the old cap.
However, check diameter of old capacitor first. This one is 22 mm dia. and 35 mm high.

I've never replaced any caps before.

Don't worry. There's not much to it. Just make sure you put the cap in the "right way" (stripe on new cap should face the same way as the stripe on the old cap). For soldering iron, I would recommend getting at least a 35W iron and leaded solder. If you can't find leaded solder, get a slightly bigger iron - 40W or more. You may be able to do it with a 35W iron, but it would be a little more challenging, especially if you have never soldered before.

Some other tips in soldering:
- make sure you iron has fully heated up before starting (5 minutes is usually enough)
- add fresh solder to joint before soldering/unsoldering - this will improve heat transfer from the soldering iron's tip. Alternatively, also get some no-clean flux (avoid plumber's flux! or flux meant for soldering copper pipes) and put that on all joints you intend to solder/desolder. This will help with the heat transfer and make the solder actually stick where it's supposed to rather than crumble and look "dry".
- avoid heating joints for too long if not needed. With good heat transfer from the iron's tip, the solder should melt in 1 to 2 seconds. On big joints, it may take a bit more. But don't hold the iron on there for more than 10 seconds and avoid moving the iron too much when soldering/desoldering a joint.

[spottydog10]

Re: caps?

Thanks momaka

Would I get away with just replacing the big CapXon do you think?
I'm trying to make it as simple as I can...
Mike

[mariushm]

Re: caps?

Absolutely not.
Those small capacitors are most likely what make the power supply go "out of whack".

The large capacitor is less important and considering it's just a bit swollen, it may not even affect the power supply right now, but you should change it as well.

You'll find that there's a lot of area around the leads of those capacitors on the other side of the board, so with a bit of patience and leaded solder, you can solder new capacitors on the board.

[spottydog10]

Re: caps?

Thanks mate.
I've e-mailed the shop with pictures to see if they have replacements inc the small ones.

"you will need to solder leads to it "
I thought they came with leads on?

Thanks,
Mike

[mariushm]

Re: caps?

The capacitor Momaka linked to is a snap-on (or snap-in) type capacitor, meaning it has thicker and shorter leads that are supposed to be just long enough to go through the board and be soldered (they're also a bit like a spring, hence the snap, because they "snap" in place a bit).

Here's a picture:



So it's basically designed to stay vertically on the board.

However, you can put it flat on the side (and maybe glue it or tape it to the pcb) and use a couple of insulated wires to extended those tiny leads to the holes on your board.

Also make sure that you can fit the capacitor in the area where the old capacitor is. It will be as wide and tall as its diameter when laid horizontally.

[spottydog10]

Re: caps?

Thanks mariushm,
So any insulated wire will do?
I'll see what that shop comes back to me with in the morning.
It seems quite complicated at the moment being a cap replacement virgin
but the monitor is no good dead so I may as well give it a go.

Mike

[Rtech]

Re: caps?

I am in harrogate.Ref the BigCap..I can send you one FOC,as I have lots of spare boards and it is a simple matter to find a good one.WHAT I need you to do is give me the dimensions ie length and width.You can PM me with the details.