Sharp R-1482, R-1480 Test Procedures, Letter, Component Test, Ltouch Control Panel Assembly Test

R-1480

R-1481

R-1482

TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST

YLW

4

HOOD FAN

CAPACITOR

5 45 Ω

RED

	BLU
	1
	32 Ω
20 Ω	2
	BLK
	3
	WHT

	Resistance between;
BLU (1)	AND	YLW (4) =		0Ω (Shorted)
BLK (2)	AND	YLW (4) =	32Ω
BLU (1)	AND	BLK (2) =	32Ω
BLK (2)	AND	WHT (3) =	20Ω
WHT (3) AND		RED (5) =	45Ω
			BLU		BLK WHT
			1	2		3
6-PIN CONNECTOR
OF HOOD FAN MOTOR

4 5 YLW RED

5.Reconnect all leads removed from components during testing.

6.Reinstall the outer case (cabinet).

7.Reconnect the power supply cord after the outer case is installed.

8.Run the oven and check all functions.

LTOUCH CONTROL PANEL ASSEMBLY TEST

The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter and ohmmeter.

In this service manual, the touch control panel assembly is divided into two units, Control Unit and Key Unit, and troubleshooting by unit replacement is described according to the symptoms indicated.

Before testing,

1)Disconnect the power supply cord, and then remove outer case. Refer to procedure of "HOOD EXHAUST LOUVER REMOVAL", "REMOVAL OF OVEN FROM WALL" and "OUTER CASE REMOVAL".

2)Open the door and block it open.

3)Discharge high voltage capacitor.

4)Disconnect the leads to the primary of the power transformer.

5)Ensure that these leads remain isolated from other components and oven chassis by using insulation tape.

6)After that procedure, re-connect the power supply cord.

1.Key Unit. NOTE ;

1)Disconnect the power supply cord, and then remove outer case.

2)Open the door and block it open.

3)Discharge high voltage capacitor.

4)Check key unit ribbon connection before replacement.

5)Reconnect all leads removed from components during testing.

6)Re-install the outer case (cabinet).

7)Reconnect the power supply cord after the outer case is installed.

8)Run the oven and check all functions.

The following symptoms indicate a defective key unit.

a)When touching the pads, a certain pad produces no signal at all.

b)When touching a number pad, two figures or more are displayed.

c)When touching the pads, sometimes a pad produces no signal.

If the key unit is defective.

1)Disconnect the power supply cord, and then remove outer case.

2)Open the door and block it open.

3)Discharge high voltage capacitor.

4)Replace the key unit.

5)Reconnect all leads removed from components during testing.

6)Re-install the outer case (cabinet).

17