Long charging period of a capacitor

[caspian]

Dear Forum Members,

I have a PC mainboard with model GA-EP41T-USB3. I want to measure resistance to GND on the the ATX_12V line (called VIN in the schematics) by my multimeter in the resistance mode. When I do this measurement, first it shows 0 ohm then some capacitor in that line starts getting charged slowly and it shows 200 ohms then more and more and finally after 3 seconds, the resistance reaches the mega Ohm range.
this resistance measurement behaves the same whenever I try to measure it.
The ATX_12V line is connected to 4 high side Mosfets too which are shorted to the CPU Vcore, but not to GND. the CPU Vcore is not shorted to GND.
internal traces of the VIN line are bulged a bit due to an excessive current that has passed through it. but the internal traces can not be seen to check whether they are connected to each other or not.

Why does resistance on the VIN line take this long period to reach the mega Ohm range? is it due to a bad capacitor? or is it shorted? or is it normal to take this long?

I have attached the schematics document of this mainboard. the VIN line and its capacitors are located in page 37 of the document.

thanks

[stj]

Re: Long charging period of a capacitor

it's what caps do, it's normal.

the meter current is very low, so the caps take time to charge.

[petehall347]

Re: Long charging period of a capacitor

now swap meter probes over .

[eccerr0r]

Re: Long charging period of a capacitor

testing in circuit or out of circuit? You should be testing out of circuit and if it still does this out of circuit, this is caused by leakage current (not electrolyte leakage.)

[petehall347]

Re: Long charging period of a capacitor

think my meter stops beeping about 30 ohms then stops beeping depending on the beep time and cap uf value ..it finds open circuit or shorted caps in circuit first then remove to confirm .. never had a esr meter . if it has been removed for further testing it gets a new one installed regardless .
yes i know its hit and miss approach but always worked for me .. swing meter was more fun to use .