In addition to your specific scenario, there are other cases where a flag can be marked as helpful even if no action was taken. For example, I am a moderator on DBA.se and I have marked flagged as helpful in these situations:


a flag has notified me of some behavior that I don't need to act on, but perhaps make a note of for later in case the behavior repeats. If doesn't always justify immediate action.
a flag as a duplicate or for migration is accompanied by close votes of the same type. In some of these cases I'd rather let the community continue to decide rather than make a binding decision. Not as a cop-out, but because I still want the community to decide how the community should work, when it makes sense for them to do so. Especially in cases where I am not familiar enough with the topic to truly determine, on my own, whether two questions really are identical. I can usually tell with SQL Server, but not so much with Oracle or MySQL.


How can a flag be helpful without any action taken?
MY QUESTION IS THIS:
Would failed power supply caps cause peripheral damage to the amp, preamp or control circuits ? Supposedly there is "protection" for "DC offset, over current and over heat"

I have a Proton AM-656 amplifier with "Dynamic Power on Demand" which is a second higher voltage supply rail (switched to when needed) that creates 6db of headroom and 2 ohm stable. I did not think there was fault protection, turns out the schematic block diagram states there is.

One day with the amp power on I tightened/snugged up the speaker binding post. There was a single frayed speaker wire (unnoticed) that shorted. The amp proceed to billow smoke. I looked inside to find several power supply caps having oozed their electrolyte onto the circuit board. 

I am shopping to recap two of my other amps and was thinking of recapping the Proton, however I do not want to waste my time if there is likely to be damage to the circuits other than electrolytic capacitors.
