UK Repairing Christmas light projector

[westward10]

A button cell may not have the power to spin it. Try a couple of AAs in series.

 

[TheJay]

I had previously used a 9V battery on a similar motor and it worked, but it didn't work on this one.

 

[westward10]

Set your meter to ohms and see if there is anything across the motor wires.

 

[Avo Mk8]

Since the motor, when connected to the pcb, causes the led to dim, and the voltage on the terminals it connects to drops from 3.2V to 0.6V, the motor seems to have a low resistance (but not work!)
Another test could be to put the multimeter on a low dc volts range, spin the motor and see if any voltage is generated by it!
If it doesn't run on a battery looks like it'd died. Have you tried spinning it while on the battery?

There must be zillions of motors out there, finding a replacement could be a challenge.
If you are able to take the pinion off the motor shaft to put on the new motor, you will need the same shaft diameter and length on the new motor, and preferably at least one fixing hole to line up!

 

[Avo Mk8]

DC 1.5V 3V 5V 6V 6600RPM Micro RF-300C Motor Small Round?​

That 300C reference looks useful.
Prompted by your post I had a quick look and they do look similar, eg:

Micro Motor 300 Solar DC 3V 4.5V 5V Motor For CD Player DIY Toy 2mm Brush Mo W02 | eBay

Lead length: 140 mm. Model: RF-300. Shaft length: 5 mm.

www.ebay.co.uk

If you have a pair of vernier callipers you could check the measurements of yours against the drawing dimensions in the link above.

They do look alike!

Good luck!

 

[TheJay]

Thanks for your replies. I have tried testing on low volts and ohms and not getting a reading when spinning. On ohms it's reporting OL.

I've ordered two dc motors, just noticed they aren't expected to arrive until 5th June though...

 

[littlespark]

've ordered two dc motors, just noticed they aren't expected to arrive until 5th June though...

Still gives you over 6 months before you need to put them up for xmas

 

[TheJay]

See post #5
If the motor is jammed it will likely take more current which could cause the voltage across it to fall.
If it won't run on a 3V battery it's probably at fault. If you can get into the whole assembly you might stand a chance of finding what's wrong. It could be the reduction gears or the optical element they turn is stuck, or the motor itself, but in my limited experience the motor bit tends to be more reliable than the plastic/nylon gear trains they drive!

PS: Are you running the whole light projector off its original power supply?

I've got a couple of things to fix where the motor seems to be the problem.

I don't understand what could be broken in this assembly? Does the circular magnet wear down over time and need replacement? If so, where can I get one?

 

[Avo Mk8]

Magnet shouldn't be a problem.
The common failures are a break in the armature coil, or the 'brush' mechanism worn or not making contact. It looks like one of the contacts is bent up (ringed), shouldn't that contact spring be straight? Or has a bit broken off!
Those two contacts should press lightly (but not too lightly!) on each side of the commutator to provide current to the coils.
Use the ohmmeter to set it up.

 

[TheJay]

Here is a closer look at the one you have referred to:

This is the one from the projector light, there are black bits on the arms?