A question for a MW expert!! 18 May 2019 at 3:33PM edited 30 November -1 at 1:00AM in Techie Stuff 12 replies 1.2K views

Nikiya

We have an old MW still in very good condition. However, the ¨start¨button has stopped working. We believe it is a contact issue, since it started being ¨dodgy¨a while ago and you needed to press it at different angles. It became more and more dodgy and now it is next to impossible to make it work.

So we were going to do something like this:
https://www.youtube.com/watch?v=N7cU417G7Qo

However, prompted by the many warnings printed on the back, I read more and learned about the dangers of the capacitor and the beryllium oxide inside the magnetron.
We got cold feet and stopped the task.
So my question for anybody who knows first hand about these devices is: is it safe to just remove the cover and check the control cables at the front? How easy is it to touch the capacitor which can supposedly kill you even if the appliance is unplugged? Can this deadly substance inside the magnetron leak out just because you removed the cover?
Many thanks for any help!! It is a shame to throw away a good device just because of a minor fault.

unforeseen

If it can leak out them I'm in trouble. I worked on high power radars for 30 years with magnetron kicking out 5MW & klystron kicking out 10MW.

More seriously, unless you physically damage the magnetron then you're safe. They are pretty sturdily built so there is no danger unless you are adjusting the switch with a 2lb club hammer and accidentally hit it.

As for the capacitor, then unplug it and leave it for half an hour. The charge will leak away through the rest of the circuitry. Even if there is some charge left then it will probably hurt if you touch it. I've had a 2kV belt off a capacitor before now on unplugged kit. Those around you learn some new swear words when that happens

that

the above video looks fairly safe.

it could be a contact issue, or if the plastic film touches the board contact, the pressing of the contact onto the board flex the circuit a bit and crack a copper track... and you may have to look very carefully to find this crack. Use you phone as a magnifying glass (in most cases)

https://www.youtube.com/watch?v=a5A61fIu0kk

When unplugged, give both surfaces of the switch a wipe with a lint free cloth. The actual pad points, give the metal bits a rub down with a pencil point - the graphite bit, but do not bridge the contacts

Another condition that occurs ic called 'Dry Joint, and occurs where a component or plug are soldered to the board

https://www.youtube.com/watch?v=5Pxuf94fdRQ
This guy should have removed the old solder, cleaned all the contact points, added flux and then soldered https://www.youtube.com/watch?v=oAa-IxuGE8Y

Do not solder onto plastic.

Norman_Castle

MW? Take your pick. https://acronyms.thefreedictionary.com/MW


I suspect MW is only a valid abbreviation when referring to microwaves and not a microwave oven.

Inner_Zone

Medium Wave?

unforeseen

I meant megawatt. 5 for the D band radar and 10 for E/F band radars that I worked on

John_Gray

Inner_Zone wrote: »

Medium Wave?

Very disappointing - I was looking forward to a discussion of the "Medium Wave in the era of DAB"...

(Maybe we will now get a thread headed "DAB", which relates to a new type of contact cleaning agent? :cool:)

that

John_Gray wrote: »

(Maybe we will now get a thread headed "DAB", which relates to a new type of contact cleaning agent? :cool:)

Here you go, but not for cleaning;;;; a:(

https://expertvaping.com/dab-pens-for-dabbers-a-beginners-guide/

MothballsWallet

Apparently a "dab" is a kind of dance move or pose these youngsters do these days, possibly seen in that Fortnite game...

It's also a species of fish.

Heedtheadvice

Ah, well remember listening to radio Luxor berg or something on MW......well that might be the name but my memory keeps 'fading'......it'll come back soon......

Heedtheadvice

Dab hand at filling in the musical gaps.........