MICROWAVE OVEN REPAIR

Some Notes About Microwave Repair

Microwave Repair-Page 1

Microwave Repair-Page 2

--------------------------------------------------------------------------------------------------------
Job# 02-11 : Date: 15/9/2011

En. Amir Hamza : 012-4881485

Via mudah.com

SAMSUNG M1600N Microwave Oven.

pic#1:front panel showing timer

Problem: 
The oven is dead, no power.

Fault found after checking: The front Timer switch malfunctioning.pic#7

pic#7:Timer switch showing  2 pairs of terminals at the bottom

Fault Finding Procedure:

First of all I discharged the big capacitor with a bulb of 100 watts directly connected to its terminals. Nothing happened. It was discharged already.

capacitor on the right of transformer

pic#3:Power supply module & fuse

1. I checked the fuse first. It was OK.I checked the power supply o/p ,it showed 250V AC.Blue & Brown wires.pic#3

2. I checked all three micro switches of the front door hinges. All found OK.pics#5,6

pic#5:microswitch behind the front door

pic#6:two more micro switches assembly:they can be snapped out

3. I checked the Timer switch which was one of the two pairs of thimble connectors. Blue & white wires. It showed S.C (short circuit)(continuity) on all positions, whether Off or ON.pic#7

The other pair of connectors were of Motor of timer which also showed S.C that means that the motor is fine &not burnt.(O.C)(open circuit).

I took the timer out & fiddled with the switch many times.. until it started clicking again, before there was no clicking sound. Also I tapped & banged it a couple of times to release any spring or latch inside to make it work again.I tried to open it slowly & carefully but when I saw the clockwork inside with plastic gears I closed it immediately.

After a while It started working again.

I also checked other parts like the fan motor (with red & balck wires connector) which was OK.(S.C)pic#2

Pic#2-Fan Motor & connector

& the light bulb at the top;with a pair of brown & white wires terminal.pic#4.It was OK too (S.C).

pic#4:connector of light bulb

Estimate given: 65RM (Agreed & confirmed) I told him If I have to replace the timer then the cost will be more.

Uploaded to the blog https://electronicsmaintenance.blogspot.com

===========================================================
NATIONAL MICROWAVE: MODEL NN9853:
FAULT: 
TRAY MOTOR NOT ROTATING

Details: 
The turntable motor was weak to take up the load & it rotated only when empty. In case you put something to heat up,it will not rotate.

Sankyo(Japan),coil Impedance=18K

Part# A6326585QP

MUL J49ZC73

AC 220/240V, 50/60Hz, 5/6 RPM, 2.5/2W

Mr.Ooi,
Chinese living near Bukit Jambul,LipSin Flats.Ph# 017-4867832

Replaced the motor & it woked fine.

Motor@10rm from Chinese shop, Kinta Road.

Charges told @115RM+20RM charged for transportation to pick Microwave from his flat.

==============================================================