On a energized power supply will a capacitor voltage read the same on both leads? I have a dead power supply and I m trying to locate the bad area.
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Re: capacitor in circut, powered up
Why not open a thread for it in a relevant section - post pictures and we will suggest
some testsPlease upload pictures using attachment function when ask for help on the repair
http://www.badcaps.net/forum/showthread.php?t=39740 -
Re: capacitor in circut, powered up
Just seeking some general knowledge. With a capacitor just conditionig voltage I was thinking that the voltages would be the same and wanted to find out if I was wrong about this.Comment
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Re: capacitor in circut, powered up
Taking the probe and contacting the capasitor leads one after the other while leaving the ground lead on the frame.This is on a hot circut. What kind of reading should I expect.With my 40 yr old training my basics really suck.Comment
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Re: capacitor in circut, powered up
It theoretically could on the primary side of the supply, but most likely will not.
Voltage across an individual primary cap could be as low as 170VDC, or up to about 400VDC if the PSU has active power factor correction.Last edited by Uniballer; 01-25-2014, 05:46 PM.Comment
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Re: capacitor in circut, powered up
Would the voltage be the same in and out????12v in 12v out or would they differ. 12v in nothing out ,I would assume would be bad.Comment
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Re: capacitor in circut, powered up
The capacitors have a negative side and a positive side.
If you want to measure voltage on capacitor, you can put the probes either way, the multimeter will measure the voltage difference between the two terminals. So, if you put the probes the other way around you'll just see the voltage with a negative sign on the multimeter screen.
You can't test if a capacitor is good by checking voltage on each side, it's not working like a resistor in the circuit.
In electronics electrolytic capacitors are almost all the time connected between the + and - of a power supply to store energy. They're not "in series" like a resistor. If you put a capacitor in series, that capacitor will only let AC move through it and DC will be blocked.
See this for something that will make you understand easier : http://electronics.stackexchange.com...citor-block-dc
later edit as you added a few posts while writing this:
Would the voltage be the same in and out????12v in 12v out or would they differ. 12v in nothing out ,I would assume would be bad.
On the secondary side, most power supplies tie the negative side to ground... the power supply is earth referenced. So if you put one probe on earth or chassis and the other on the negative side of the capacitor you would measure 0 or close to 0, with the probe on + you would measure the output voltage.
On the primary side, where those large capacitors are, it's a bit tricky. Often, that section is "floating" or in other words, not referenced to ground. The two AC wires from the socket come in a bridge rectifier and get converted to DC and you get a virtual ground (the -) and the virtual plus (the +) ... there may be no connection between the chassis and that - on the primary side.Last edited by mariushm; 01-25-2014, 06:17 PM.Comment
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Re: capacitor in circut, powered up
OK Now I get it,took a while. Thanks for the remedial electronics lesson. I needed it.Comment
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hello.
I have Sega Saturn and 5 years ago, I recapped all of capacitor in the Power supply, Because At that time, It frequently freezed black screen after SEGA logo displayed.
It hardly ever freezed after I finished to recap all of caps in the power supply.
But Yesterday, It did not show any screen at all and its green power LED constantly blinked.
To my surprise I found that all of two NXH 10v 2200uf capacitors in the secondary area of Power supply have been bulged and It measured 57 mF and 75 mF capacitance.
It seems that quality... -
These cheap non brand capacitors at it again
Last night we had a power outage [ long drawn out trying three to come back up before going out completely ] and when I went to turn the DVR camera recorder back today no go 3 bad capacitors ( one capacitor no ESR reading on DVR board the other 3 capacitor on the power supply board over 40 ohm this is not a misprint ) on the external switching power supply and one capacitor on the DVR camera recorder board where the power supply that goes to the hard drive disk is
Well at least I have the cameras back on line I to try the... -
I have a klipsch kda-500 that would turn on and allow me to get into the web management but it was picking up a lot of noise from audio sources so i decided to replace the smd caps on the power supply along with radial one. Some one was in here before me and they basically burned the bottom side of the traces off for the radial cap but i was able to repair it without any real problem. I thought i did a good job sourcing out replacement caps but apparently not and now i can't get the power supply to turn on it just constantly try's to keep turning on. Attached is a picture of the power supply before... -
I have been working on this concept for quite some time now with limited success but recently I found a switching power supply that is setup for the voltage that this soldering station needs to operate at however it also needs part of the secondary circuit from the original switching power because you need several voltage rails
I once tried to get a ZD-915 desoldering station to work on a 18 volt battery power supply but unfortunately things did not go well but I did find a work around but I might try this idea again but going at a little differently more about this another time... -
Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming...
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