CTC211_DigiCon_Power_Supply_Trlbshoot_A362097FFFC2AAB0E0339DFEEACCAAB0_25.pdf part of RCA D52130 RCA_CTC210-211_01.rar, Large File 6 pare RAR Folder containing: Flow Charts, Tech Tips, Trouble Shooting Manuals, Updates, Module Training, and Symptom Fixes text manual preview

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Digital Convergence Power Supply Overview
The digital convergence power supply utilized in the CTC211 chassis is a switch mode supply. The on/off signal for the supply is the +12Vr (run) supply from the main chassis. Raw B+ from the chassis is applied to the output transistor Q701. The oscillator Q702/703 drives Q701. The output from Q701 is coupled through T702. There are four (4) primary convergence power supplies, +20V, -45V, 20V and +7.5V. The +20V is used as the feedback reference voltage for regulation (via Q713). The regulator / reference signal is applied to the opto-isolator (U702) whose output is applied to the osc/driver circuit which in turn controls the duty cycle of the power supply. The opto-isolator is used to isolate hot from cold ground on the input side. The transformer T702 provides this isolation on output side. The 20V and +7.5V supplies along with the +12Vr are routed directly to the Digital Generator circuit board where other supplies are developed.

Troubleshooting the DigiCon Power Supply
1. 2. 3. 4. 5. Check for Raw B+ (J19700-1) Check for +12VrIO @ JW19365 (11, TT) convergence board Check On/Off circuit (Q705 thru Q709) Check Power Supplies on Convergence PCB If no power supplies are active, disconnect the convergence yokes (J19310 and J19311) to unload the supply. 6. Repeat step 4, if power supply came up troubleshoot convergence output stage. 7. Check active components

Convergence PCB
NOTE: All components & TP's are 19000 series unless otherwise indicated.

DigGen PCB

3.3 Reg U505

+3.3VDigg +6.8VDigg +12VrDigg +5VrDigg -12VDigg CR12503

+12VrIO (from main run supply) TP JW365 Conv Pwr Supply ON/OFF Q705/6/7/8/9

L/C/R CR12506 CR12504

120VAC Line In

F200

RAW B+ CR201
TP Q701-D

TP14201 ~ 160VDC ~

-20V CONV -20V CONV
TP JW705 TP JW709

TP Q701-G

OptoIsolator U702

Osc/ Driver Q702/3

Power Output Q701

Output Pwr Trans T702

- 45V CONV

- 45V CONV +20V CONV
TP JW379

Ref U701

Feedback Reg/Ref Q713

+20V CONV
+20V Conv Feedback TP JW707