Thanks so far Cydrome, Matt, and Jon for reading and replying with
suggestions for finding the board problem. Last night I identified
every device on the board and made a list. The only things not on the
list are the resistors. I checked each one to see if the resistance
was the same as what the colored bands show and they all checked out
fine. The list of the rest of the components follows.
Thanks for reading.
Eric
FADAL 1040-2A INTERFACE CIRCUIT BOARD DEVICES

U1-Motorola - SN74LS122N RETRIGGERABLE MONOSTABLE MULTIVIBRATORS
U2 STMicroelectronics T74LS08BI QUAD 2-INPUT AND GATE
U3- NATIONAL - DM7406N Hex Inverting Buffer
U4- NATIONAL - DM7406N Hex Inverting Buffer
U5- NATIONAL - DM7406N Hex Inverting Buffer
U6- NATIONAL - CD40106BCN Hex Schmitt Trigger
U7- BI Technologies - 898-1-R15K Dual In-Line Thick Film Resistor
Network
U8- LM393P DUAL DIFFERENTIAL COMPARATOR
U9- NATIONAL - DM7406N Hex Inverting Buffer
U10- NATIONAL - DM74ALS273N Octal D-Type Edge-Triggered Flip-Flop
U11- NATIONAL - DM74ALS273N Octal D-Type Edge-Triggered Flip-Flop
U12- NATIONAL - DM74ALS273N Octal D-Type Edge-Triggered Flip-Flop
U13- NATIONAL - DM74ALS244AN Octal 3-STATE Bus Driver
U14- NATIONAL - DM74ALS244AN Octal 3-STATE Bus Driver
U15- NATIONAL - DM74LS14N Hex Inverter with Schmitt Trigger Inputs
U16- NATIONAL - DM74LS14N Hex Inverter with Schmitt Trigger Inputs
U17- NATIONAL - DM74LS14N Hex Inverter with Schmitt Trigger Inputs
U18- NATIONAL - DM74LS14N Hex Inverter with Schmitt Trigger Inputs
U19- NATIONAL - DM7406N Hex Inverting Buffer
U20- NATIONAL - DM7406N Hex Inverting Buffer
U21-AMD 26LS33PC QUAD DIFFERENTIAL LINE RECIEVER
U22-AMD 26LS33PC QUAD DIFFERENTIAL LINE RECIEVER
U23- NATIONAL - DM74ALS273N Octal D-Type Edge-Triggered Flip-Flop
U24- NATIONAL - DM74LS14N Hex Inverter with Schmitt Trigger Inputs
U25- BI Technologies - 898-1-R15K Dual In-Line Thick Film Resistor
Network
U26- NATIONAL - DM74ALS244AN Octal 3-STATE Bus Driver
U27- NATIONAL - DM74ALS244AN Octal 3-STATE Bus Driver
U28- NATIONAL - 555CN TIMER

CR- ICL8069DCSQ - LOW VOLTAGE REFERENCE

C1- SQUARE FILM TYPE 103K
C2- DIPPED ELECTROLYTIC TYPE 10 uF
C3- SQUARE FILM TYPE 103K
C4- SQUARE FILM TYPE 103K
C5- SQUARE FILM TYPE 103K
C6- DIPPED ELECTROLYTIC TYPE 10 uF
C7- SQUARE FILM TYPE 103K
C8- SQUARE FILM TYPE 103K
C9- SQUARE FILM TYPE 103K
C10- SQUARE FILM TYPE 103K
C11- DIPPED ELECTROLYTIC TYPE 10 uF
C12- SQUARE FILM TYPE 103K
C13- DIPPED ELECTROLYTIC TYPE 47 uF
C14- SQUARE FILM TYPE 103K
C15- SQUARE FILM TYPE 102K
C16- SQUARE FILM TYPE 102K
C17- SQUARE FILM TYPE 102K
C18- SQUARE FILM TYPE 102K
CAP BRIDGING U21- SQUARE FILM TYPE 102K

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