Capacitor replacement

Hey guys,

Once i broke off a capacitor from a arduino Uno board. The capcitor is a surface mount so i also cant solder it(i even tried with small connecting wires but coudlnt). I thought of replacing the capacitor. This is the board i am using

The capacitor is 100uF and 25v. But i only have a 100uF 10V and a 470uF 10v. I was wondering if the 10v is enough.


The cap is on the 5V bus line? Then 10V rating is fine.

It’s a guess the capacitor is probably on the Vin side of the regulator.

It appears in the image the Vin diode cathode goes to the + side of the capacitor.

When Vin is 7v you should be okay with a 10v capacitor, however, a higher than 7v level is going to place stress on the capacitor and might even blow it up !


If you are powering the Arduino from the USB port or +5v pin the capacitor is not needed.

10V on a 10V capacitor is actually fine, working voltage ratings are used on electrolytics, not absolute maximum.
The leakage current specifications for electrolytics typically assume full rated voltage.

ok then, i guess if i use arduino with only 5-10v then everything will be 'perfect'.
Anyway i will mostly operate my arduino with 8V.

If you are powering the Arduino from the USB port or +5v pin the capacitor is not needed.

I should have mentioned this, but without the capcitor it shows some error when uploading the program, thats why i am not ablw to use it

I should have mentioned this, but without the capacitor it shows some error when uploading the program, that's why i am not able to use it

Do you mean you are powering it via "Vin" or the "barrel jack"? That should have no effect when only the USB is connected to program it.

Really, you should not consider powering it via "Vin" or the "barrel jack" as a viable means. The electronics operates on 5 V, so you should be powering it fom 5 V.

My routine advisory:

The clear blunder is not comprehending what the "Vin" or "RAW" terminal is. The regulator on the Arduino UNO/ Nano/ Pro Mini/ Mega2560/ Leonardo/ Pro Micro has very little heatsink, so will not pass very much current (depending on the input voltage and thus, how much voltage it has to drop) before it overheats and (hopefully reversibly) shuts down. It is essentially a novelty provided in the very beginning of the Arduino project when "9V" power packs were common and this was a practical way to power a lone Arduino board for initial demonstration purposes. And even then it was limited because an unloaded 9 V transformer-rectifier-capacitor supply would generally provide over 12 V which the regulator could barely handle.

Nowadays, 5 V regulated switchmode packs are arguably the most readily available in the form of "Phone chargers" and switchmode "buck" regulators to regulate down from 12 V or other available voltages are cheap on eBay so these can be fed into the USB connector or (more appropriately) 5 V pin to provide adequate power for most applications. Unfortunately, many tutorials or "instructables" are seriously outdated or misleading and have not been updated to reflect the contemporary situation.

If powering from batteries, as long as the battery pack cannot exceed 5.5 V, this must be connected to the 5 V pin.