Answer
As a C/E will present the PSC that Emcy Fire pp was tried out on weekly basis and maintained in good order at all times. Convince the PSC to give Code17: Rectify before departure else will give a Code30 because the Emcy Fire pp was in-operational this make the ship unseaworthy and unsafe.
A team along with 2/E will try to rectify the issue at the earliest while PSC onboard and present PSC that LB engine is working satisfactory
If PSC leaves before Emcy Fire pp become operational: Another team of self and Master will look after reporting of detention to the relevant authorities, make an Incident report and conduct RCA fo the same and look after urgent spares request/complete pump/maker/shore assistance if needed to avoid any commercial loss/reputation to the vessel. After Emcy Fire pp was made operational than master will report to the PSC with video/photo of Emcy Fire pp working in satisfactory condition. Than further inspection depends on the professional judgment of PS CO to verify and confirm than issue code30/10 or 17/10.