Re: Tek 577 D1 Repair (B07xxxx)


Jack2015
 

4. (B108xxx,My 2nd 577 D1)
2020-Nov-2~8: Max 8 traces displayed on screen(9 lines included the baseline)

Checked the staircase signal:
Saw only 8 steps, 660mV /per step <-------NG (should be 10 steps,500mV/step)
https://groups.io/g/TekScopes/photo/255563/1?p=Created,,,100,2,0,0

Adjusted the step amplitude VR(A1 Board) and got the staircase of 10 steps (500mV/step).
https://groups.io/g/TekScopes/photo/255563/3?p=Created,,,100,2,0,0
https://groups.io/g/TekScopes/photo/255563/0?p=Created,,,100,2,0,0

5.(B108xxx,My 2nd 577 D1)
2020-Nov-9~15: The Collector supply disabled light turned on right at power on.

Checked Q588(2N2222,50V,0.8A):
Vc=+12V
Vb=+1.3V <-------NG Vbe=+1.3-(-12)=13.3V>>0.7V
Ve=-12V
Vbe open

https://groups.io/g/TekScopes/photo/255563/4?p=Created,,,100,2,0,0

Fixed this issue by replacing the 2N2222 with a 2sc1384(50V,1A).

https://groups.io/g/TekScopes/photo/255563/2?p=Created,,,100,2,0,0

Join TekScopes@groups.io to automatically receive all group messages.