Oscilloscope issue

[nuryev]

Thanks to all who suggested trouble-shooting strategies for CD63KI audio drop out. After checking the player's RF using a 20mhz Aron scope, the problem still persists.

I now have a GW Instek 653 (50Mhz) oscilloscope that may or may not have a fault. While the 20mz scope is able to generate a clear eye pattern for the player, the 653 only generates the section of the pattern to the right of section which indicates the triggering status. ( I hope this makes sense). I have tried adjusting the controls to resemble the older 20mhz but still the extreme left of the eye pattern is not displayed. I have attached pics.

Any advice will be appreciated.
Thanks

 

[AndrewT]

post a pic showing the switch settings.

 

[gmphadte]

Check the trigger settings and horizontal trace should be slowed down.

Gajanan Phadte

 

[nuryev]

Swith settings

Switch settings pic attached. Thanks for the suggestion gm. I will check them.

 

[lcsaszar]

Try CH1: 0.2 V/div, AC coupled. Trigger AC, norm. Time x10 mag do not push. Horiz display A. Adjust trig level until you get a trace, then adjust Time until you see the eye pattern.

 

[nuryev]

Thanks oshifis, I have followed your clear instructions but only get a display on auto, all adjustments on Trigger AC, norm display a black screen with an odd flash of green when I turn the Time adjuster.

 

[macboy]

It definitely looks like it is not triggering, try adjusting the trigger level manually, to be around zero volt with positive edge. But it is a little hard to tell, since the 2nd photo is so small and blurry.

Sometimes when a trigger is set to "auto", and the scope can't trigger, it will free-run, meaning it just triggers randomly and repeatedly so that you can at least see that there is a signal being input.

p.s. this thread probably should have been started in "Equipment & Tools".

 

[PlasticIsGood]

Horizontal position?

 

[gmphadte]

Sometimes, you may be successful by adjusting trigger holdoff.

Gajanan Phadte