View single post by iceman
 Posted: Sun Nov 8th, 2009 06:37 pm
PM Quote Reply Full Topic
iceman



Joined: Wed Apr 6th, 2005
Location: Uzbekistan
Posts: 76
Status: 
Offline
Hi Konnan,

To quote our erudite leader

"Never replace a part unless you have proof that the part is bad."

http://fixitnow.com/wp/2005/09/23/samurais-12-laws-of-appliance-repair/

Let us consider.  You have used a special tool to remove tamper proof fasteners to gain access to the POWER Printed circuit board of a device designed to emit MICROWAVES.  Presumably you read the prominent safety warnings on the unit as you did so.  Suppose that you did manage to replace enough parts to make it work.  Lets postulate some follow-on questions:

1) Was the arcing caused by grease or by the normal failure mode of this product?

2) How long will it work for before it fails again?

3) Are you comfortable being near this device while it is operating under your fresh repair?  How about your kids?

4) Could your repair result is a fire when you are not at home?

OK, let's assume that you have decided to disregard the cautions above and are prepared to assume full responsibility of the consequences of your repair or losses resulting therefrom.  Here are the logical steps the I would follow if I had decided not to just replace the unit.

1) Try to obtain a schematic of the power converter board. 

2) Failing that, write down all the part numbers of the power devices (FETs, Diodes, BJTs).  The really damaged ones might be illegible

3) Get the data sheets for the defective devices.

4) De-solder all power devices and test them.

5) Replace the defective ones.

Once again, I STRONGLY recommend that you dispose of this microwave and go get a new one.  That is what I did, and I am very satisfied with it.  This project has exponentially diminishing returns.

Oh, and don't forget the flip Panasonic the bird.

 



____________________
iceman