Wich chip did you change??
Is there a way of testing the psu???
Im not sure if the psu delivers de 15V
I didn't change chip as I said above and others said it was a DNS issue if you are mining and some big pools like Viabtc.
Actually, it solve my issue recently by switching to their new domain stratum+tcp://btc.viabtc.top:3333.
About PSU if you have a tester you can test the PSU connector positive should be the red wire and the negative polarity should be the black wire and it should provide 12v not 15v that's overvoltage.