Special Function; Details & Waveforms On System Test & Debugging - NAD T744 Service Manual

SPECIAL FUNCTION

FEATURE
RESET FOR AH VERSION
RESET FOR C VERSION
NTSC / PAL SELECTION
VFD ALL DISPLAY
AM FREQ. STEP
VERSION CHECK
DETAILS & WAVEFORMS ON SYSTEM TEST & DEBUGGING
T89C51RB2 (U202) main clock is at 20MHz (X202)
T89C51RD2 (U201) main clock is at 20MHz (X201)
UPPER - +5V supply to KEYBOARD when power up
LOWER - RESET line (TCM810LENB713) when
power up
NOTE: The waveforms are based on software version V2.12.
KEYS PRESS ON FRONT PANEL
VIDEO 6 + SOURCE UP
VIDEO 6 + SOURCE DOWN
VIDEO 6 + MEMORY
VIDEO 6 + TONE DEFEAT
AM/FM + FM MUTE
VIDEO 6 + TONE CONTROL
UPPER - OUTPUT ENABLE (pin 24) of EPROM
(W27C02) when changing SURROUND MODES
LOWER - CHIP ENABLE (pin 22) of EPROM
(W27C02) when changing SURROUND MODES
SCLK (pin 43 of CS49326)
LRCLK (pin 42 of CS49326)
MCLK (pin 30 of CS49326)
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