Lecroy 9314L scope goes nuts from time to time after pressing auto trigger

[slow_rider]

I have bought this scope a few months ago at an electronic junkyard after making sure everything is working well. Overall the scope is in good condition, only had to replace a single encoder which was bad.
I only started using it a few days ago (need 4 channels) and I have noticed that from time to time after selecting the auto triggering mode, the scope will display random vertical lines while and clock and time are still showing, these lines will move up and down for a few seconds after that that only static lines will show up on the screen. The only way to move along is to reset the device. This happens once in 10 to 20 times I push the auto trigger button. I have looked through the service manual but could not find anything immediate.

Any thoughts on this?

*** Sorry for the picture quality, the light was dim.

[alm]

Sorry, no advice except that this looks like a digital (acquisition memory/ADC?) problem to me. Maybe our resident Lecroy expert Wuerstchenhund has any ideas? Send him a PM if he does not respond within a couple of days. You might also search the Lecroy owners group (public mirror) for similar problems.