Commodore 1940 - Field Adjustment Procedure

FIELD ADJUSTMENT PROCEDURE _____ IIIII __ IIliIIIII ___ _
Use A-4000(COMMODORE PC) or equivalent.
HORIZONTAL HOLD ADJUSTMENT
1) Connect electrolytic capacitor 1iJF 50V between TP2 (+) and ground (-).
2) Apply the crosshatch pattern signal of NTSC hires/PAL hires (15.7KHZ) mode and adjust H. Hold 1 control
VR508 to get the upright crosshatch pattern just after stopping the crosshatch pattern waving horizontally.
3) Apply DBL NTSC/DBL PAL(29.6KHZ) mode signal and adjust H. Hold 3 Control VR526 to get the upright
crosshatch pattern just after stopping the crosshatch pattern waving hrozontally.
4) Remove the 1iJF 50V capacitor.
HORIZONTAL PHASE (CENTERING) ADJUSTMENT
1) Adjust horizontal phase control VR904 to position the video display equidistant from the left and right edges of
the illuminated raster when NTSC hires/PAL hires (15.7KHZ) mode signal is applied.
2) Adjust horizontal phase control 2 VR514 to position the video display equidistant from the left and right edges
of the illuminated raster when DBL NTSC/DBL
PAL (27.6 KHZ) mode signal is applied.
HORiZONTAL SiZE ADJUSiiviENT
1) Turn slug of H. Width Coil L503 Counterclockwise to decrease width, and clockwise to increase width for the
specified width (approximately 260mm).
VERIZONTAL SIZE ADJUSTMENT
A. WORLD TRADE MODEL
1) Adjust the vertical size Control VR905 until the specified vertical size display (ablut 186mm) is obtained when
DBL
PAL. Hires MODE with crosshatch pattern is applied.
2) Adjust the vertical size 4 Control VR412 until the specified vertical size display (about 186mm) is obtained
when
PAL. Hires MODE with crosshatch pattern is applied.
3) Adjust the vertical size 2 Control VR410 until the specified vertical size display (about 186mm) is obtained
when EUR072 MODE with crosshatch pattern
is applied.
4) Adjust the vertical size 3 Control VR411 until the specified vertical size display (about 180mm) is obtained when
VGA 350 MODE with crosshatch pattern
is applied.
B. UUCSA MODEL
1) Adjust the vertical size Control VR905 Auntil the specified vertical size display (about 186mm) is obtained when
MSCAN AA MODE with crosshatch pattern
is applied.
2) Adjust the vertical size 4 Control VR412 until the specified vertical size display (about 186mm) is obtained
when NTSC. ·Hires MODE with crosshatch pattern
is applied.
3) Adjust the vertical size 2 Control VR410 until the specified vertical size display (about 186mm) is obtained
when EUR072 AA with crosshatch patten
is applied.
4) Adjust the vertical size3 Control VR411 until the specified vertical size display (about 180mm) is obtained when
VGA350 MODE with crosshatch pattern is applied.
VERIZONTAL CENTER ADJUSTMENT
Adjust the vertical center control VR903 to center the character area.
SIDE PINCUSHION ADJUSTMENT
Adjust the Side Pincushion Control VR451 for the optimum side pincushion.
19