In part 3 of this video series on repairing this CG5011 I attempt to take a closer look at troubleshooting the DC frequency mode fault symptom shown in part 2. Unfortunately there is no conclusion to this repair at the end, but I do end up ruling some things out.

The final conclusion in part 4 here!    • Tektronix CG5011 Oscilloscope Calibra...  

0:00 – Intro/recap
3:04 – Edge mode risetime on TDS754D
6:18 – TM5003 +26V rail ripple
8:11 – TM5003 -26V rail ripple
9:18 – CG5011 power supply check
11:13 – HV supply check 120V & 240V
14:03 – HV supply check -120V & -240V
15:06 – further troubleshooting of HV supply
18:48 – Low SAC check
25:26 – SAC Chopper check
29:11 – SAC Chopper defective?
32:32 – Programmable Voltage Reference Check
38:49 – High SAC Check – Defective?
44:45 – Higher Volts/Div Freq mode settings look fine
46:54 – HV Supply Adjust – looks normal
51:37 – Testing High SAC relay K1101 – works fine
52:57 – Outro (unresolved ☹)