Voltages in the columns marked (*2) tested with an expensive professional 3 ¾ digit auto-ranging multimeter on the DC setting.
Test program:
Code: Select all
10 FOR a=0 TO 7
15 BEEP 0.1,1
20 PAPER a: INK a: BORDER a: CLS
30 PAUSE 50
40 LET i$=INKEY$
50 IF i$=“” THEN GO TO 30
60 NEXT a
70 GO TO 10
Voltages in the columns marked (*2) tested with an expensive professional 3 ¾ digit auto-ranging multimeter on the DC setting.
IC14 voltages when a completely white picture (ink, paper and border all white) is being shown:
Pin 1, 9.676V (Chroma Lead)
Pin 3, 5.14V (Chroma Bias)
Pin 5, 0V (Ground)
Pin 6, 0.544V (not used)
Pin 7, 0.83V (not used)
Pin 8, 0.83V (not used)
Pin 9, 0.62V (not used)
Pin 10, 4.608V (not used)
Pin 11, 4.635V (not used)
Pin 12, 12.121V (Video input)
Pin 13, 4.163V (Chroma Sub-carrier, output) #1
Pin 14, 12.145V (+12V)
Pin 15, 12.145V (+12V)
Pin 16, 12.145V (+12V)
Pin 17, 8.768V (Chroma Osc Output)
Pin 18, 9.695V (Chroma Lag)
Note #1 the loading of the test equipment may affect the picture.
All voltages tested with an expensive professional 3 ¾ digit auto-ranging multimeter on the DC setting.
Mark