Stupid voltage question

Bad Karma · 12-13-2009, 11:58 PM

I've read through some of the stickies and did some basic searches and have found some confusing/conflicting posts this subject. Basically, I have five bulging 470uf, 25v caps on the power supply/inverter board for an old Viewsonic monitor. I have on hand five 470uf, 50v caps. I've already desoldered the bad caps. Can I replace them with the 50v ones?

Sorry if this question is hellatiously newbish or repetitive. This is my first cap replacement ever.

etnietering · 12-14-2009, 12:06 AM

Yes, you can use the caps, assuming they'll physically fit, and have the same or better ripple current/esr ratings. The 25v caps might be on a 20v circuit. This is the maximum voltage that the cap will be charged to. It's far less than 50, so the voltage won't be a problem. If they don't physically fit, well, then they don't fit. If the ripple current/esr ratings aren't as good, it will probably work for a little while, but there might be stability issues and/or the new caps won't last very long.

You can start a thread in the computer monitor section, post the caps that are currently there, the ones you plan on using to replace them, and some pictures and you'll get tons of great advice. Good luck!

Toasty · 12-14-2009, 12:08 AM

Yes, you can go up in voltage.

I try to go no higher than the next step,16->25->35->50->63->?, but from 25 to 50 is fine. A nice benefit is you can end up with a lower ESR and a higher ripple current capability for the same capacitance when you do that. PSU makers do it a lot by using a 10v cap on a rail that only needs a 6.3v.

What brand & series are you replacing and with what brand & series.

Post back with that info. I'd like to make sure you're not trading blown crap for crap that will blow. I know, anything is likely better than the blown ones you have, but let's not waste time doing it twice.

Toast

Bad Karma · 12-14-2009, 12:26 AM

Thank you all for your prompt responses.

The replacement caps were from a digikey set I had at the office (I'm a systems administrator). The caps themselves are Panasonic Type A series? In any case, I went ahead a installed them and the LCD works like new! Life is good.

Toasty · 12-14-2009, 12:39 AM

Glad it's working. That was quick!

Never heard of those Pannies...

Toast

12-13-2009, 11:58 PM	#1
Bad Karma New Member Join Date: Dec 2009 Posts: 2	Stupid voltage question I've read through some of the stickies and did some basic searches and have found some confusing/conflicting posts this subject. Basically, I have five bulging 470uf, 25v caps on the power supply/inverter board for an old Viewsonic monitor. I have on hand five 470uf, 50v caps. I've already desoldered the bad caps. Can I replace them with the 50v ones? Sorry if this question is hellatiously newbish or repetitive. This is my first cap replacement ever.

12-14-2009, 12:06 AM	#2
etnietering Badcaps Veteran Join Date: Apr 2009 City & State: Michigan Posts: 320	Re: Stupid voltage question Yes, you can use the caps, assuming they'll physically fit, and have the same or better ripple current/esr ratings. The 25v caps might be on a 20v circuit. This is the maximum voltage that the cap will be charged to. It's far less than 50, so the voltage won't be a problem. If they don't physically fit, well, then they don't fit. If the ripple current/esr ratings aren't as good, it will probably work for a little while, but there might be stability issues and/or the new caps won't last very long. You can start a thread in the computer monitor section, post the caps that are currently there, the ones you plan on using to replace them, and some pictures and you'll get tons of great advice. Good luck!

12-14-2009, 12:08 AM	#3
Toasty Badcaps Veteran Join Date: Jul 2007 City & State: East Coast, USA Line Voltage: 220-221 I'm a: Professional Tech Posts: 3,915	Re: Stupid voltage question Yes, you can go up in voltage. I try to go no higher than the next step,16->25->35->50->63->?, but from 25 to 50 is fine. A nice benefit is you can end up with a lower ESR and a higher ripple current capability for the same capacitance when you do that. PSU makers do it a lot by using a 10v cap on a rail that only needs a 6.3v. What brand & series are you replacing and with what brand & series. Post back with that info. I'd like to make sure you're not trading blown crap for crap that will blow. I know, anything is likely better than the blown ones you have, but let's not waste time doing it twice. Toast

12-14-2009, 12:26 AM	#4
Bad Karma New Member Join Date: Dec 2009 Posts: 2	Re: Stupid voltage question Thank you all for your prompt responses. The replacement caps were from a digikey set I had at the office (I'm a systems administrator). The caps themselves are Panasonic Type A series? In any case, I went ahead a installed them and the LCD works like new! Life is good.

12-14-2009, 12:39 AM	#5
Toasty Badcaps Veteran Join Date: Jul 2007 City & State: East Coast, USA Line Voltage: 220-221 I'm a: Professional Tech Posts: 3,915	Re: Stupid voltage question Glad it's working. That was quick! Never heard of those Pannies... Toast

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