There is a reason why internal trouble shooting manuals exist. These are documents created for similar scenarios, albeit once technological obsolescence takes over, they are usually burried in some archive.I would not say gone altogether, but experiences count and are handed down. If there is no continuation?
Recently what PLAAF has done with obsolete / retired aircrafts, by turning them into drones, raises the point that proper and accurate documentation should be maintained, just in case, obsolete aircrafts can be used again.