Hi all, thanks for your replies To provide more info, the TV is a large commercial one in an office setting, and does have an earth connection via the IEC connector.
It is also connected to the data network via the ethernet cable, and then to the computer via the HDMI cable.
It didn't occur to me that it might be the TV at fault to be honest I was thinking it was the fixed wiring circuit related, but reading through your responses this seems like the most likely thing at fault is the TV, under fault conditions caused by the unrelated shorts happening.
Difficult to test through really without causing a deliberate short on the socket circuit and potentially sacrificing another PC.
I've just checked the failed PC and the power supply is fine and has worked in another PC so it is the mother board that has died, which points to the problem coming in on the HDMI cable from the TV.
EDIT just to add the PC's were connected to the TV during the two incidents, they are permanently connected.
It is also connected to the data network via the ethernet cable, and then to the computer via the HDMI cable.
It didn't occur to me that it might be the TV at fault to be honest I was thinking it was the fixed wiring circuit related, but reading through your responses this seems like the most likely thing at fault is the TV, under fault conditions caused by the unrelated shorts happening.
Difficult to test through really without causing a deliberate short on the socket circuit and potentially sacrificing another PC.
I've just checked the failed PC and the power supply is fine and has worked in another PC so it is the mother board that has died, which points to the problem coming in on the HDMI cable from the TV.
EDIT just to add the PC's were connected to the TV during the two incidents, they are permanently connected.