Choosing better replacement caps for display

[WatercoolerWarrior]

I have a fade-to-black monitor with clearly failed radial-lead electrolytic capacitors (bulged tops/bottoms, leaking electrolyte on the caps themselves) that I'm replacing. The capacitors in question are all 470/1000uf caps rated at 10/25V, 105C; packaging is about 10mm diameter, 16mm height, and I think 5mm lead separation. They're all manufactured by Elite (I know... I'm replacing the ones that look fine, too). I have a solid if rusty soldering background, and the basic tools for board rework, but I'm fuzzy on electrolytic capacitor details.

(1) Is there an issue with me going to higher voltage ratings on most/all of the caps - for example, getting replacement caps all rated at 50V?

(2) Are there other specs I need to worry about? .

(3) From the Good Caps thread, I'm under the impression that Nichicon/Nippon/Chemicon/Rubycon/Panasonic are probably the most generally reliable brands for electrolytic capacitors. True?

(4) Just for kicks, is there any benefit to switching to another type of capacitor?

[selldoor]

Re: Choosing better replacement caps for display

Is there an existing post for the monitor make/model. I would just use panasonic FR FM or FC in that order ( Not all sizes available in all series.) from a good source - digikey? not ebay unless you are absolutely sure about the seller.

Depending on which monitor there may be known problem caps on the main or inverter.

Re 4 you might have difficult fixing other caps - single sided/ multilevel board?

[WatercoolerWarrior]

Re: Choosing better replacement caps for display

Thanks, selldoor - I didn't even think about the fact that this may be a model with known issues.

This is a Hanns-G HW191D monitor, manufactured in November 2007. I've attached front and back photos of the power board. Although it's a bit difficult to see (and I've done basic cleanup) all of the radial caps on the right half of the board have some leakage and swelling at top.

[selldoor]

Re: Choosing better replacement caps for display

cant see any other issues - wow you have a lot of bad caps hope they have not killed anything. before you recap may be worth testing the inverter transformer secondary windings. It is the gray oblong centre top with label no starts DG1000. No Power to the board- Look on the back of the board and find the 4 corner solder joints. Set your meter on ohms 2000 and test top to bottom at each end. Also there are 3 red barrel fuses - meter on ohms 200 - result should be the same as holding your probes together. Having said that if your monitor switches on they are probably ok

There is no need to increase the voltage ratings if you use panasonic caps.

[WatercoolerWarrior]

Re: Choosing better replacement caps for display

cant see any other issues - wow you have a lot of bad caps hope they have not killed anything. before you recap may be worth testing the inverter transformer secondary windings. It is the gray oblong centre top with label no starts DG1000. No Power to the board- Look on the back of the board and find the 4 corner solder joints. Set your meter on ohms 2000 and test top to bottom at each end. Also there are 3 red barrel fuses - meter on ohms 200 - result should be the same as holding your probes together. Having said that if your monitor switches on they are probably ok

There is no need to increase the voltage ratings if you use panasonic caps.

+Transformer secondaries check - about 4 ohms relative to shorted VOM.

+ Red barrel fuses, 0 ohms

+ Corner solder joints is one I have trouble with, since I don't know what I'm looking for; these are the same as the 4 screw mounting points? Looking at the board from the back, AC socket at bottom: the 2 left-hand joints and the bottom right all have zero resistance relative to each other. Top right is isolated from the other 3.

And it looks like the replacement caps are surprisingly cheap.

[selldoor]

Re: Choosing better replacement caps for display

Meter on ohms 2000 test S1 to S2 and S3 to S4
Joints may be lacquered or have dry flux make sure you get a good contact

[WatercoolerWarrior]

Re: Choosing better replacement caps for display

Meter on ohms 2000 test S1 to S2 and S3 to S4
Joints may be lacquered or have dry flux make sure you get a good contact

I'm glad you mentioned the potential for them being lacquered - they were. I finally managed to make good contact on S1-S2 and S3-S4; each came out to 576 ohms.

[selldoor]

Re: Choosing better replacement caps for display

That looks good then - sometimes shell out for caps then find a bad transformer
that may be expensive or even unavailable.
I am away for a couple of weeks hope you fix it ok

[WatercoolerWarrior]

Re: Choosing better replacement caps for display

Thanks for your help; I've got the caps ordered and will know in a few days if this works. I went with Panasonic FR, identical ratings to the originals, but 8-9k hours rated.
Enjoy your time away, and once again, thanks for the help. You've saved me hours of research time.