Hitachi v352 oscilloscope repair help

[lame_turtle]

Hi

I got a v352 a few months ago that I wanted to restore. Channel two was blown, so I replaced the tr101 and everything worked again . I decided I would recalibrate the scope eventually so I recapped it and started using it.
 After a few days I hadn't turn it on, I fire it up just to see a sinewave on both channels without anything connected on the inputs.
I do have a ds1054z if a second oscilloscope is needed.
Any idea where to start looking ?

Thank you

Edit: I used the scope a bit more to understand what's happening.
All the controls/functions do work on the scope !
The only problem is the scope is only showing a sinewave. Not even a flat line when nothing is connected or the coupling set to gnd. This is happening on both channels.
Nothing is obviously burned up inside the scope.

[shakalnokturn]

A good starting point is to check all power supply voltages and ripple.

[lame_turtle]

Sorry I didn't mention. Psu checks out fine.  Tested it and checked for ripple.

[tunk]

What's the frequency and amplitude of the sine wave?

[lame_turtle]

Found it. Both k30a's where toast. I did have some spares and the scope is back giving a nice flat line when grounded.
I'll do a full repair report with photos in the next few days. 

Thanks