Translation:Well, I will pay then, if it is working again.
The person won't pay as soon as it is possible again. The person will pay when it is possible. The person is not in a hurry, the person will pay later. as soon as = sobald ; Nun, dann werde ich zahlen, sobald es wieder geht.
Maybe "possible" is a bit too unliteral. Maybe it works. I haven't tried it. Literal "possible" would be: Nun, dann werde ich zahlen, wenn es wieder möglich ist.
"Sobald" implies urgency, "if" does not.
Secondly, "if" implies that there is a possibility "it" may not work again. "Sobald" however does not say anything about that possibility. It is just that the reader interprits, in case "it" never works, the time of payment will never come.