Tektronix TLA 720, Service Manual

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Theory of Operation
3–2
TLA 720 Benchtop Chassis and TLA 7XM Expansion Chassis Service Manual
The enhanced monitor board (A3) collects the monitoring information from the
power supply, blower, and temperature sense board and passes the information to
the 25-pin D connector. The enhanced monitor board connects directly to the
backplane at 0J3, 0P1 and 0P2.
The 25-pin D passive monitor connector lets you monitor the power supply
voltages, blower speed, and the maximum slot temperature rise within the
chassis. The connector also provides remote on and off capability and access to
the SYSRESET* and ACFAIL* signals.
CAUTION.
Do not connect an RS-232 cable to the 25-pin connector.
This 25-pin connector is not an RS-232 port.
Connecting an RS-232 cable to this connector might result in damage to the
equipment.
The blower connects to the enhanced monitor board at FAN 1/Blower (J8). The
fan speed switch (S1) lets you select either variable fan speed (VAR) or full
speed (FULL).
The temperature sense board (A2) monitors the temperatures for each slot within
the chassis. The temperature sense board connects to the backplane through the
ribbon cable at J16.
Enhanced Monitor Board
Temperature Sense Board