Tektronix 070-5992-05 User Manual

Maintenance

760A / 760D / 760N

PIN 18

DELAY makes a low–to–high transition when the current signal value
is 

≥

 the stored peak value.  This clocks the current value into the peak

value latch and starts the peak–hold time–out circuit.

PIN 19

BAR ENABLE goes low when a segment should be lit.

The following pins are internal nodes without external connection.

PIN 13

LCMP is a delayed and inverted CMP signal.

PIN 14

PEAK goes high when the first peak segment should be turned on.

PIN 15

DPEAK goes high when the second peak segment should be turned on.

PIN 16

S, S and CLEAR (PIN 17); are state variables for a state machine that
looks for the low–to–high transition of TIMEOUT.

The equipment needed to troubleshoot the power supply:

H Digital Multimeter (DMM), with a diode check function

H Oscilloscope

H 0 to 20 VDC Variable Power Supply

H Clip Lead – to short across a component

H High Voltage Probe, w1 GW input resistance

The Troubleshooting Procedure for the Power Supply (Assembly A1) is split into
two sections, the Low Volts and High Volts Supplies.  Start the procedure by
determining which section of the power supply the problem is in.  Apply AC
power and turn on the power supply.  From Table 4–1, determine which
symptom the power supply exhibits and refer to the corresponding procedure.