@Lodgewoman The PSU fault is a very specific condition, it shows itself as in two methods, the router boots goes into operation then about 5 minutes later it drops out back to green and tries to go back online, sometimes it will do a green/flash white back to green again. At this point the PSU does not have enough power to hold the modem stage in operation and is more common with the SH31B version that has the modem to the fttc copper connection.
By the sound off the fault you have the connection is just dropping off and that can be for other reason's, so best to day what you have Router wise and how it is connected either FTTP for full fibre or FTTC for the partial fibre/copper cable connected to an OR Openreach Master Phone socket!
It also has been established now that it is only the PSU that goes bad and the Router remains in a healthy working condition, but that may not always be the case!
