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Copyright © 1998-2005 by John C. Gallawa. All rights reserved worldwide.

AMANA
Models: DQ22HS, RC22, RC22S, RC22MP, RC22MPS, MC22MP, MC22MPT (Commercial models)
Symptom: Display shows PCE6
Problem: This is what Amana refers to as a "communcations failure" and could be caused by any of the following:
  1. Broken or improper wire connection between high voltage board and low voltage board.
  2. Inoperative cable between low voltage board and extended memory board.
  3. Inoperative high voltage board
  4. Inoperative low voltage board
  5. Inoperative extended memory board
Solution: Carefully check for broken, loose or misplaced wires. Repair as necessary. At present there is no practical way to isolate a defective circuit board other than replacing it.


KENMORE (Sears)
Model: 564.8878430
Symptom: Electrical burning smell during cook.
Problem: Shorted magnetron tube.
Solution: Replace magnetron tube.


PANASONIC
Model: NN-6371WM
Symptom: Stopped working after lightning storm
Problem: Built-in surge protection on printed circuit board has opened. This circuit consists of a fine foil pattern (or filter coil - depending on the model) that acts to fuse the primary side of the low-voltage transformer.
Solution: Rebuild the surge protection circuit. Replace the varistor


PANASONIC Model: NE-8021, NE-8051, NN-4208A, NN-5407, NN-5500A, NN-5512A, NN-6370WM, NN-6371WM.N, NN-6372AWM, NN-6381A, NN-6482A, NN-6503A, NN-7524AK
Symptom: No heat, weak heat, or intermittent heat
Problem: Magnetron filament connectors have loosened and, due to resistive heat, the terminal connections have deteriorated and burned off.
Solution: Repair defective terminals as follows:Either (1) Cut away burned wire, clean the magnetron terminals, and replace the slip-on connectors, or (2) Cut away burned wire and connector(s). Clean terminals to prepare for soldering. Solder filament leads directly to magnetron terminals. Be careful not to apply soldering heat any longer than necessary


SHARP
Models: R-22DP, R-4A53, R-4A54, R-4A73, R-4A83, R3A53, R-4A93, R-4H80, R-5A98, R-7A82, R-7A85, R-8010
Symptom: Oven went dead, perhaps in the middle of cooking, and possibly accompanied by a faint electrical burning smell.
Problem: Weakened fuse clips in the fuse receptacle causing fuse to melt due to resistive heat. Usually indicated by a bead of solder leaching out from either endcap and/or evidence of overheating (or burned spot) at the endcap, fuse clip, or terminal connection
Solution: Replace 15 amp fuse (about $1.00) and receptacle (about $2.00) Note:In many cases, the fuse comes as a kit that includes an interlock switch. The Sharp part # FFS-BA015. Price:about $9.00
Additional Info: Generic fuses and fuse holders are available at appliance and electronic part suppliers.


SHARP
Model: R-8310
Symptom: Convection heat is too hot-burning things.
Problem: Opened thermistor
Solution: Replace thermistor. Sharp part # FH-HZ0017WRKO. Price:about $39.95


SHARP
Model: R-3A75, R-4A84, R-4K52, R-5A50, R-5A82, R-5A84, R-5F80, R-5K81, R-4260, R-4840, R-5560, R-5565, R-9200, R-9350, R-9480
Symptom: Arcing in cooking the compartment
Problem: Bits of food or other cooking debris has lodged beneath the waveguide cover (or stirrer cover, depending on the model). After repeated exposure to microwave energy, the cooking residue breaks down into carbon (which a conductor) and arcing occurs. This results in a burned spot in the waveguide cover.
Solution: Clean out all residual grease and cooking debris. Remove all traces of the blackened residue (carbon) from in and around the waveguide opening (use a light grade of sandpaper if necessary, but never use steel wool),. Finally, replace the waveguide cover. Price:about $5.00 - $7.00


TAPPAN
Model: 56-4675-10/02, 56-4677-10, 56-4804/06, 56-4884-10, 56-5897/01
Symptom: Fan comes on but the oven doesn't heat.
Problem: Cracked solder joints on printed circuit board.
Solution: Remove printed circuit board and examine it for cracked, burned, or deteriorated solder connections. In particular, check the solder joints where the harness connector is mounted. Clean, reinforce, and re-solder as necessary.


WHIRLPOOL
Model: MW8500XR, MW8520XP, MW8550XL, MW8650XR, MW8650XS, MW8750XP
Symptom: Weak or uneven heat
Problem: Broken stirrer belt
Solution: Replace stirrer belt. Part # 311958 Price:$5.00


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