I have a 7704A with 2 x timebase: 7B53 and 7B50
The 7B50 has developed a fault suddenly and the screen is now all lighting as green and cannot see the trace anymore when using this timebase
The led for on the 7B50 still appears to sync with the input signal but the screen of the scope is all lighting green when using that timebase
Swapping the timebases also keeps the fault with the 7B50 which shows this is not a problem with the 7704A chassis itself
I am wondering how to start troubleshooting the 7B50 and whether that fault is a known issue?