Question black marker or spot on PSU capacitors.

[ironphoenix43]

what are these black marker spots on my PSU capacitors? are they are sign of blown capacitors or is just some sort of marking. when inspecting the PSU nearly all of them have these marks. even some that aren't capacitors have the mark

 

[Grobe]

No, these are not sign of damage. Probably marked by the manufacturer for a reason not revealed to the public.

 

[--SID--]

Marked during quality control by the manufacturer.

 

[ironphoenix43]

thank you for the quick reply. a few days ago i had a weird smell that lasted for like 10 or 15 seconds. it smelled like as if when you leave a candle wick burn itself dry, which lead me to start looking around. if a capacitor was to blow or if a smell was coming from the PC would it be constant. or would it appear as a one off and never smell it again?

Edit: i live in an apartment, it is possible that the smell came from a neighbor and myself i do burn incense sticks. so these possibly could of been the culprits

 

[Grobe]

Burnt electronic components does not smell like a candle wick.

 

[--SID--]

A new PSU always smells now and then the first few weeks of use. It's the solder flux used in manufacturing.

 

[Misgar]

Electrolytics on the secondary side of an ATX PSU often have a "cross" shaped indent or crease on top. It's a weak spot designed to let overpressure gas escape from a failing capacitor, instead of exploding in a more dangerous fashion.

If your PSU is very old and tired, you might have smelled gas bursting through the top of a dying capacitor. Once the capacitor has burst, further gas emissions are likley to be much smaller and hence not as easily detectable. Unlikely, but it's one possible explanation. It might equally well be your joss sticks or the neighbours cat.