TM 11-6625-3053-14
ITEM
MALFUNCTION
CHECKS/CORRECTIVE ACTION
Voltage should be approx 23 VDC.
If voltage is not obtained, go to T/S item 13, check 7.
If this voltage is obtained, check C1, C2 and R5 of the A2 assy
and replace faulty component.
5. If voltages measured in checks 3.a) and 4 above were correct.
Replace Q4. If this does not restore voltage of 21 VAC as called
for in check 2.a.1 above, then replace Q2.
6. If voltages measured in checks 3.b) and 4 above were correct.
Replace Q3. If this does not restore voltage of 21 VAC as called
for in check 2.a.2 above, then replace Q1.
9
Beam Current Faulty.
1. Aline -325V Beam Supply per alinement step 1 if not previously done.
If beam current still faulty, to to check 2 below.
2. Aline -750V voltage supply per alinement step 2 if not previously
done.
If beam current still faulty, go to check 3 below.
3. Aline filament voltage per alinement step 3 if not previously done.
If beam current still faulty, go to check 4 below.
4. Grid voltage check.
a) Remove high voltage cover (para 6-22).
b) Set sig gen to initial settings of para 2-4 and energize.
c) Wait 2 mins and set MODULATION Switch to CW.
d) Using multimeter set to 1000 VDC range, measure grid voltage
between GROUND test point and GRID test point on the A4
tracking board assy.
Voltage should read approx -317.5 VDC.
If this voltage is not obtained, go to T/S item 11.
If this voltage is obtained, go to check 5 below.
6-60
