GE Advantium SCA2000BCC, Руководство по обслуживанию

Страница: 49 / 62

– 47 –
this service guide for details and diagnos-
tic information).
7. Check upper and lower halogen lamp op-
eration at power level 10 and again at
power level 5 to be sure that lamps are
cycling properly. At this point you must
have a thorough understanding of power
level operation, upper halogen lamp bal-
ance operation, and thermal compensa-
tion (see pages 24-27 and page 59 of this
service guide for detailed information).
8. Confirm that thermal compensation is
operating properly, by following the ham-
burger recipe selection test outlined in the
thermal compensation section of this ser-
vice guide (see page 26).
DIAGNOSING A “DEAD” UNIT
A “dead” unit is better defined as a unit that ap-
pears to have no power to it (no clock display,
oven cavity lamp, or keypanel responses).
The following components and associated wir-
ing should be checked in the below order when
diagnosing a “dead” unit.
1. Confirm power at the electrical outlet (120
volts AC on each leg - L1 to Neutral and
L2 to Neutral).
2. At the power cord head, use your volt/ohm
meter and check the resistance from L1
to Neutral. The resistance should be ap-
proximately 24.5 ohms. Note: the resis-
tance reading that you just made is shown
in the schematic diagram at the upper right
hand corner of this page (low voltage
transformer primary resistance).
3. If you do not read continuity from L1 to
Neutral, suspect the following:
- Open fuse
- Open cavity thermal cut out (T.C.O)
- Low voltage transformer (open pri-
mary winding)
- Open magnetron tube thermal cut out
- Open thermal fuse
- Defective smart board
- Check all associated wiring and wir-
ing connections
3. If you read approximately 24 ohms from
L1 to Neutral suspect a defective smart
board, loose wiring connection or open
secondary winding of the low voltage
transformer.
L2
L1
G
N
POWER CORD
CN11
CN1
ONE SHOT
w
R
L1 L2 N
SMART
BOARD
24.5
Ω