3-6. TROUBLESHOOTING CHART
Use the troubleshooting chart to localize and isolate trouble. The chart supplements the direct support
troubleshooting chart of paragraph 2-6 and the foldouts at the back of this manual.
The troubleshooting chart is Indexed by MALFUNCTION/SYMPTOM for which PROBABLE CAUSES are listed.
Follow the TEST PROCEDURES for which in turn an INDICATION and YES or NO instructions are given.
(1) ON-OFF SWITCH (CB1) CONTINUES TO
Defective: Power source. Circuit breaker CB1.
Circuit board A9.
Do not hold ON-OFF switch at ON.
1. Check polarity and voltage to PRIMARY
Go to 2.
POWER connector J8.
and +27 vdc
2. On the inside of the front panel remove the
L-shaped compartment housing (refer to
para 2-9), check CB1 continuity with power
(2) NO TEST METER OR SCOPE READINGS
Defective: Circuit board A9. Series regulator
FOR ANY POSITION OF METER
Transistors Q1, Q2, Q3. Connector J8.
1. Connect ME-26B/U across terminal 5 on
Go to 2.
board A9 (or E-37 on panel); measure
voltage. Refer to figure on next page.