Had a donk run down on a 707 over Germany , enroute to LHR. Wouldn't relight either.
Aircraft had a history of hot starts or late light offs.
Turned out to be sludge caused by the foam backing from a carpet left in a wing tank during maintenance. Filters didnt touch it till it blocked the burners.
Seemed that in investigating the starting problem, the ground guys drained the suspect tank BUT didnt tank it off as waste merely put it in the centre tank.
The manual allowed feeding from the centre to all engines with one other tank as a back up. Wouldnt have worked well as a back up with all engines blocked!