it's looks more like damaged due to high temperature exposure from those NTC, wash it with Ethanol and see actual corrosion and damage
It is possible that the NTC has failed and the relay contacts have burnt out.
befor that relpace & that check out those NTCs , one of them looks damaged , it's looked crack open the 2nd from top down, also 4th looks also cracked open, take all of the out then check properly then get some new one if possible bigger diameter with same ohm's rating, it's possible that something else also damaged in your's build , look again carefully
I hope you replace these soft starter boards with a decent one which have fuse for each toroidal you are putting there , right now these soft-starter boards looks a bad choice , they don't have individual fuse for each of the toroidal you have put on it , so make sure that your toroidal are OK and not shorted out , and make sure to put fuse on each primary of them too.
Sorry for bad English , it's not my first or 2nd language
they have failed , they looked carked open , they might got very hot 🔥🔥🔥🔥 then carked open.
but NTC getting carked open or shorted out doesn't result in realy contacts to be burnt out or short shut, unless there might be a possiblity that Toroidal itself or Amp boards have damaged somewhere , which is why there is higher current flowing and damageing the relays and NTC a like .
I hope that guy check out his Amp boards and toroidal properly
you can make this very simple Soft-Starter , it's effective and its does his job well.
here is the video link
from Sir Tony titled as
from XrayTonyB, watch it you will get better understanding from the video itself. how this works
I have made this one recently and its works as said in video , I only added fues on both end of it , 1st fues in AC socket then 2nd fuse in soft-starter , 2 fuse for primary AC Voltage Input
here is the video link
"Adding a Soft Start Circuit to a Power Supply"
from XrayTonyB, watch it you will get better understanding from the video itself. how this works
I have made this one recently and its works as said in video , I only added fues on both end of it , 1st fues in AC socket then 2nd fuse in soft-starter , 2 fuse for primary AC Voltage Input
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