Fault Finding Procedure - Philips PM 5775 Manual

Ii. FAULT FINDING PROCEDURE
With the aid of the fault finding procedure on the block diagram (Fig. XIH-1) one
can easily determine that part of the circuit which is faulty. The procedure starts
with the measurement of the output pulse on sockets PULSE OUT, P3 (P6) and is
then further self-explanatory.
The encircled figures both in the block diagram and the circuit diagrams refer to
the adjacent figures of the pulse diagram photographs.
Measuring instruments required:
Voltage measurements : Voltmeter 40 kQ/V PHILIPS PM 2411
Oscillograms : Sampling oscilloscope PHILIPS PM 3400
Cathode follower probe PHILIPS PM 9345
Attenuator heads PHILIPS PM 9341
The oscilloscope should be externally triggered with the sync. output pulse taken
from the pulse generator (connect the signal via a 20 dB attenuator, e.g. Texscan
FPS50, BNC Outline A).
Test conditions of PM 5775 (PM 5776)
REPETITION TIME Sl 1 ps
REPETITION TIME FINE RV1 black dot
DELAY 82 Sns *
DELAY FINE RV2 black dot
WIDTH $3 15 ns
WIDTH FINE RV3 black dot
DC OFFSET IN 50 Q RV4 (RV6) OV
AMPLITUDE IN 50 S4 (S9) +1V
Vernier RV5 (RV7) MAX.
CONT.GATED S6 CONT.
SINGLE DOUBLE S7 SINGLE *
NORM. INV. S8 (S10) NORM.
Voltages and waveforms are typical and may vary between instruments.
All voltages given in the diagrams are in volts.
* Oscillograms 8' and 10° are obtained at a DELAY setting of 50 ns and with
switch SINGLE DOUBLE, 87, in position DOUBLE.