Isolation Test – Two Magnetron Models
!
WARNING
To avoid risk of electrical shock, personal injury, or death, disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
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If the customer is complaining of low heat, it may be necessary to isolate the upper and lower high voltage systems.
Method 1
1. Be sure outercase wrapper and back panel are installed on the oven.
2. Place a water load in the oven.
3. Confirm antennas are rotating.
4. Operate the oven for 60 seconds on full power.
5. Discharge air from both magnetrons should be warm.
6. If the discharge air from one magnetron is significantly cooler than the other, a problem may exist with the
cooler magnetron.
Method 2
1. Unplug oven and discharge capacitors.
2. To prepare oven for LOWER MAGNETRON high voltage system check, locate the Gray # 3 jumper wire
that connects between the capacitors.
3. Remove jumper wire connection from both capacitors and position wire to prevent any short to electrical
components.
4. Follow the guidelines for performance test (1000 ml. of 60º F (16º C) water for 33 seconds) and record the
temperature difference and confirm antenna is rotating.
5. To prepare oven for UPPER MAGNETRON high voltage system test check, unplug oven and discharge
capacitors.
6. Remove Red High Voltage Transformer wire # 4 from left hand capacitor (looking from the rear) and move
to the right hand capacitor.
7. Repeat step # 4 above.
Example using model HDC18:
Performance test with both magnetrons operating should be minimum of 18º F (10º C) Temperature rise. With either
magnetron operating individually, temperature rise should be a minimum of 9º F (4.5º C) for each system.
# 3 Wire
Gray jumper
from LH to RH
capacitor
# 4 Wire
Red
