Fixed the microwave turntable.
 

I got a new `motor` for the turntable £5 on ebay and that sorted the non
turning turntable.
Out of interest I dismantled the `not working` one and it appears that
when in use liquid has been allowed to spill out and leak through the
the spindle to the motor. As far as I can see I just need to clean up
the cogs of all the sticky stuff that has accumulated on them.
From the image one part has wiring, is there any way to check if this
is ok as in not broken as I intend to put it back together to see if it
still works. I have a multi meter but dont know how to use it for this
part. (continuity?)

https://imgur.com/aZJBBkj

Fixed the microwave turntable.
 

On Fri, 11 Sep 2020 00:05:21 +0100, ss wrote:

I got a new `motor` for the turntable £5 on ebay and that sorted the non
turning turntable.

Cool.

Out of interest I dismantled the `not working` one

Good man. ;-)

and it appears that
when in use liquid has been allowed to spill out and leak through the
the spindle to the motor.

Given the spindle sits under the turntable and can't normally be
accessed directly, that could either be from something boiling over
and running under the turntable or over zealous cleaning and liquids?

As far as I can see I just need to clean up
the cogs of all the sticky stuff that has accumulated on them.

I can't see the picture here for some reason (I just get a black
screen in Chrome or FF but this is an old XP box) but you might first
need a solvent for the spilled stuff (hot soapy water?) and then a
soak in say paraffin followed by good dry out and re-lube of any
bearings or re-grease any gears etc?

From the image one part has wiring, is there any way to check if this
is ok as in not broken as I intend to put it back together to see if it
still works. I have a multi meter but dont know how to use it for this
part. (continuity?)

Yes, you are looking for ohms across the motor coil. Might be around
100 ohms but that's just a bit of a guess.

If it's short circuit (0 ohms) or infinity then it's faulty.

Cheers, T i m

Fixed the microwave turntable.
 

On 11/09/2020 00:05:21, ss wrote:
I got a new `motor` for the turntable £5 on ebay and that sorted the non
turning turntable.
Out of interest I dismantled the `not working` one and it appears that
when in use liquid has been allowed to spill out and leak through the
the spindle to the motor. As far as I can see I just need to clean up
the cogs of all the sticky stuff that has accumulated on them.
From the image one part has wiring, is there any way to check if this
is ok as in not broken as I intend to put it back together to see if it
still works. I have a multi meter but dont know how to use it for this
part. (continuity?)

https://imgur.com/aZJBBkj

Set meter to resistance, say 20k and measure. I suspect/guess you should
see 2k or so. If the meter doesn't show a change when connected to the
winding then it's probably open circuit.

To be honest the pic looks a mess and not obvious its going to clean up!

Fixed the microwave turntable.
 

T i m wrote:
On Fri, 11 Sep 2020 00:05:21 +0100, ss wrote:

I got a new `motor` for the turntable £5 on ebay and that sorted the non
turning turntable.

Cool.

Out of interest I dismantled the `not working` one

Good man. ;-)

and it appears that
when in use liquid has been allowed to spill out and leak through the
the spindle to the motor.

Given the spindle sits under the turntable and can't normally be
accessed directly, that could either be from something boiling over
and running under the turntable or over zealous cleaning and liquids?

As far as I can see I just need to clean up
the cogs of all the sticky stuff that has accumulated on them.

I can't see the picture here for some reason (I just get a black
screen in Chrome or FF but this is an old XP box) but you might first
need a solvent for the spilled stuff (hot soapy water?) and then a
soak in say paraffin followed by good dry out and re-lube of any
bearings or re-grease any gears etc?

From the image one part has wiring, is there any way to check if this
is ok as in not broken as I intend to put it back together to see if it
still works. I have a multi meter but dont know how to use it for this
part. (continuity?)

Yes, you are looking for ohms across the motor coil. Might be around
100 ohms but that's just a bit of a guess.

If it's short circuit (0 ohms) or infinity then it's faulty.

Cheers, T i m

https://www.appliancefactoryparts.co...s/142575-2.pdf

TURNTABLE MOTOR 1. Remove wire leads
2. Measure resistance. Normal: Approximately
(ohm meter scale: Rx1000) 2.0 to 3.0 Kohms

But that's a 120V microwave service manual, and a microwave
with a higher mains voltage will likely use a different motor.

Google search term: "microwave motor ohms"

rather than just search for a manual.

I was hoping to see some values for the HV cap, but no such luck.

Paul

Fixed the microwave turntable.
 

These motors seldom die though, unless something has corroded where wires
join or the actual coating on the coil has been attacked by something, but
if it went short I'd expect there to be evidence, like a blown fuse or
charred and melted components.
Brian

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This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"T i m" wrote in message
...
On Fri, 11 Sep 2020 00:05:21 +0100, ss wrote:

I got a new `motor` for the turntable £5 on ebay and that sorted the non
turning turntable.

Cool.

Out of interest I dismantled the `not working` one

Good man. ;-)

and it appears that
when in use liquid has been allowed to spill out and leak through the
the spindle to the motor.

Given the spindle sits under the turntable and can't normally be
accessed directly, that could either be from something boiling over
and running under the turntable or over zealous cleaning and liquids?

As far as I can see I just need to clean up
the cogs of all the sticky stuff that has accumulated on them.

I can't see the picture here for some reason (I just get a black
screen in Chrome or FF but this is an old XP box) but you might first
need a solvent for the spilled stuff (hot soapy water?) and then a
soak in say paraffin followed by good dry out and re-lube of any
bearings or re-grease any gears etc?

From the image one part has wiring, is there any way to check if this
is ok as in not broken as I intend to put it back together to see if it
still works. I have a multi meter but dont know how to use it for this
part. (continuity?)

Yes, you are looking for ohms across the motor coil. Might be around
100 ohms but that's just a bit of a guess.

If it's short circuit (0 ohms) or infinity then it's faulty.

Cheers, T i m

Fixed the microwave turntable.
 

On 11/09/2020 03:35, Fredxx wrote:
To be honest the pic looks a mess and not obvious its going to clean up!

Yes it is a mess but if the wiring checks out ok I can clean the rest up
that wont be a problem.

Fixed the microwave turntable.
 

On 11/09/2020 09:23, ss wrote:
Yes it is a mess but if the wiring checks out ok I can clean the rest up
that wont be a problem.

Ok zilch reading from the multi meter, on closer inspection I can se
some broken wires so thats that little exercise finished and heading to
the bin.

Fixed the microwave turntable.
 

On 11/09/2020 00:05, ss wrote:
I got a new `motor` for the turntable £5 on ebay and that sorted the non
turning turntable.
Out of interest I dismantled the `not working` one and it appears that
when in use liquid has been allowed to spill out and leak through the
the spindle to the motor. As far as I can see I just need to clean up
the cogs of all the sticky stuff that has accumulated on them.

Are you sure that its not the grease applied during manufacture?

https://www.youtube.com/watch?v=CzhcJDqQ_h0&t=1s

Video of some American who hasn't got a clue why he got a shock from a
microwave turntable motor when driving the spindle with an electric
drill. His dismantling of the motor does show grease around the gears.

So to see if the motor is OK attach a drill to the shaft that drives the
turntable, put your tongue across the two terminals and turn on the
drill at the highest speed. If you feel a slight tingle on your tongue
the motor is likely to be OK.




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mailto : news {at} admac {dot} myzen {dot} co {dot} uk

Fixed the microwave turntable.
 

I think mine has though.

I forced back the knurled metal 'clips' that held
the gearbox casing together and the gears were fine,
plenty of grease.
I tried connecting the motor to the mains and nothing
happened, not even a buzzing. Resistance across
the power tags a couple of mega-ohms.

Andrew

On 11/09/2020 08:11, Brian Gaff (Sofa) wrote:
These motors seldom die though, unless something has corroded where wires
join or the actual coating on the coil has been attacked by something, but
if it went short I'd expect there to be evidence, like a blown fuse or
charred and melted components.
Brian

Fixed the microwave turntable.
 

Andrew wrote:
I think mine has though.

I forced back the knurled metal 'clips' that held
the gearbox casing together and the gears were fine,
plenty of grease.
I tried connecting the motor to the mains and nothing
happened, not even a buzzing. Resistance across
the power tags a couple of mega-ohms.

Andrew

When it comes to enamel wire and magnetics, the place
where the wire solders to any post, is a weak spot. On
coils at work, that's where I was seeing failures.

Failures elsewhere are still possible. Poor quality wire,
aluminium wire! and so on. They sometimes wind motors with
Al rather than Cu to save a buck. Some pumps use Al.

Also, be aware there are two kinds of motors. AC Mains
motors, and 21VDC motors. Don't connect the wrong kind
right to mains. If the label on the motor admits to
mains AC and is not a DC motor, then go right ahead.
*Never* connect stuff to mains, without some evidence
it's the right thing to do :-) It makes Thor the god
of electricity angry when you do that. Thor will send
the magic smoke.

Paul