Peering down into the analzer tray I can see the glow of leds- probably LOCKED\UNLOCKED leds

AHA- Synth lock test shows analyzer unlocked. So perhaps a bad loop. Any common fault- bad components that you have heard of causing this? Caps? I don't think there is any CAL related adjustments that woul unlock a loop. Or is there? Any help will be appreciated. Hard to find at the best of times ...

Thanks for the reply. Yes scope works. Zero span will sweep when you change ms/div. If you change span it will start sweeping then stop. Then go to zero span and change ms/div. will start to sweep continuosly. I can get it to sweep continuously only in zero span.

Hello Wowbagger
I was a 1200 tech for a private company (we had 150 1200 boxes) and went to Wichita twice for training. Perhaps I can help with repair advice on the 1200's. The new place I work out of has a Com 120B with 2 problems. I have the maint./cal manual but the block diagrams help only up to ...