Fisher & Paykel MR720, MR730, MR700 Performance Check MR480, Dual Probe Temperature Test

		iv
4.0 CIRCUIT OPERATION			9
4.1	Introduction		9
4.2	Control Board		9
	4.2.1	Control Thermistors	9
	4.2.2	Input Analog Switches U8 and U9	9
	4.2.3	Analog to Digital Converter U10 b,d,e	9
	4.2.4	Processor Control U3	9
	4.2.5	Power Line Interrupt (Revisions D/F PCBs)	10
	4.2.6	Power Line Interrupt (Revision H PCB and later)	10
	4.2.7	41 °C Comparator	10
	4.2.8	Heaterplate Overtemperature	10
	4.2.9	Watch Dog	10
4.3	Power Board		11
	4.3.1	Revision D/F PCBs	11
	4.3.2	Revision H AND J PCBs	11
4.4	Probe Temperature versus Thermistor Resistance		11
5.0 CALIBRATION			12
5.1	Introduction		12
5.2	Equipment Required		12
5.3	Calibration Procedure for Models with Revision D PCBs or earlier		12
5.4	Calibration Procedure for Models with Revision F PCBs or later		12
6.0 PERFORMANCE CHECK			14
6.1	Introduction		14
6.2	Performance Check MR730/720/700		14
	6.2.1	Equipment Setup Notes:	14
	6.2.2	Setup	14
	6.2.3	Temperature Control Check MR700/720/730	14
	6.2.4	Alarms check MR700/720/730	15
6.3	Performance Check (MR480)		15
	6.3.1	Equipment Required	15
	6.3.2	Setup	15
	6.3.3	Temperature Control Check (MR480)	15
	6.3.4	Alarms check - MR480	16
6.4	Dual Probe Temperature Test		16
	6.4.1	Equipment Required	16
	6.4.2	Test Procedure	16
7.0 SERVICING INFORMATION			17
7.1	Introduction		17
7.2	Printed Circuit Board Removal		17
	7.2.1	Control PCB	17
	7.2.2	Power PCB	17
7.3	COMPATABILITY		17
	7.3.1	Hardware compatability	17
	7.3.2	MR480 Transformers	18
	7.3.3	Software compatability	18
7.4	Heaterplate		18
	7.4.1	Heaterplates with screw-in standoffs	19
7.5	Fault Location		19
7.6	Screw Torque Settings		19

Ref. 185040646 *MR730/720/700/480 Technical Manual ¯ Revision F ¯ Issued March 2001