TurboChef Technologies, Inc. C Series
6-10
Defective Current Transformer on Computer Board
SMT Board (T0265) Background:
During the o peration of the microwave system, the control board monitors current in the
microwave ci rcuit by means of a current transformer mounted on the controller board.
The current transformer must see at least 6 amps in order for th e microwave to energize.
If it fails to register 6 amps, the I/O board may be defect ive and the oven will prematurely
turn OFF the magnetron and display a "LOW MAG CURR/F3 MAG CURR" message.
Figure 6-2: SMT Board (T0265)
Checking the controller current transformer
Step 1: Place oven in TEST mode. Press BACK key until the oven screen d isplays " OVEN OFF" then
Press and hold the BACK and ENTER keys simultaneously and then ke y in PIN # 9-4-2-8 (access code)
then ENTER. This will allow you to enter into the test mode to manually energ ize the magnetron.
Step 2: Place a load inside the oven (about 275ml of water or an approxim ate amount inside a coffee cup).
Step 3: Clamp an ammeter on K4-1 wire (same wire going thru CT1 on contr oller board), and energize the
magnetron by pressing and holding the MGTRON key for about 10 seconds. If your meter measures
current (approximately 9 Amps+/- 2) and the W indicator at the bottom of the sc reen does not un-highlight
while energizing the magnetron, replace the computer board. If the meas ured current is between 6 and 7
Amps then double loop the wire thru CT1 twice, then perform a self test. If the self test fails then replace
board.
CT1