Tektronix 684A User Manual

Installation

TDS 684A, TDS 744A, & TDS 784A Service Manual

Memory modules with on-board batteries allow the TDS 684A and 7XXA Digi-
tizing Oscilloscopes to retain some types of data upon loss of the AC power
source. The stored adjustment constants, saved front-panel settings, current
front-panel settings (instrument status), and waveforms saved in memory are
retained.

The on-board batteries of the memory modules have a shelf life of about five
years. Partial or total loss of stored settings upon power on may indicate that the
memory modules need to be replaced.

The following environmental requirements are provided to ensure proper
operation and long instrument life.

Operate Digitizing Oscilloscopes where the ambient air temperature is from 4

_ C

to +45

_ C (+50_ C for the TDS 7XXA) with no diskette in the floppy drive.

Store the oscilloscopes in ambient temperatures from –22

_ C to +60_ C with no

diskette in the floppy drive. After storage at temperatures outside the operating
limits, allow the chassis to stabilize at a safe operating temperature before
applying power.

The Digitizing Oscilloscopes are cooled by air drawn in and exhausted through
their cabinet side panels by an internal fan. To ensure proper cooling of the
oscilloscope, allow at least two inches clearance on both sides and 3/4 inch on
the bottom of the oscilloscope. (The feet on the bottom of the oscilloscope
provide the required clearance when set on flat surfaces.) The top of the
oscilloscope does not require ventilation clearance.

Consider the following information when you power on or power off the
instrument, or when power is interrupted due to an external power failure.

Upon power on, the oscilloscope runs a power-on self check. If it passes, the
oscilloscope displays a “passed” status message and a prompt to press CLEAR
MENU to continue. If it fails, the oscilloscope displays a diagnostic log that
identifies the area(s) that failed and a prompt to press CLEAR MENU to