Early Accurist quartz, quartz testing and replacement.

[mpe7383]

This has been a quick weekend project whilst awaiting spares to arrive.

The watch is an early Accirist quartz, late 70s probably, with a Swiss ESA 9632 7 jewel movement. Inspected and could see no evidence of battery leakage, popped in a new battery and zero signs of life, so stripped down to better inspect the circuit board. Long story short, I diagnosed the quartz oscillator being at fault and the purpose of this post was to share my jury rigged method for testing the quartz.

So the tricky thing about testing the quartz is that you need to power up the board whilst also getting the required access to the legs on the oscillator, so for my power source, this is my method:

Then you need to be able to apply the voltage to the correct terminals on the circuit board, for this, this is my solution:

Then carefully set up the board in these clamps 

Crocodile clips from my battery pack onto the correct polarity brass screws and that's the board now powered up, and I've got good access to the legs of the oscillator.

The board I'm now testing is from a scrap job lot watch that I'm going to harvest the oscillator from, this one is working fine.

For those not too familiar with the quartz oscillator, from cheap watches to expensive watches, oscillators are all the same in that they all operate at 32.768 k htz, early ones can be quite big and of different shape, but a more modern replacement will still work fine. If you have a very small quartz to replace, you will need a similar size replacement.

This is the original size of the oscillator, its actually a different circuit board than the one I'm working on, this board has problems with the microprocessor chip and this oscillator may be fine, but if I'm going to change my faulty one, then I may as well use a newer replacement.

This is the oscillator which I have tested from the donor now soldered into the circuit. I left the old legs in place and soldered onto these, much easier and less risk of causing heat damage and lifting tracks on the circuit board.

Movement re assembled as much as needed to see if it works, all working fine. Movement now fully stripped and given the full service works. I quite enjoy these early quartz movements, all the wheels are metal, and as this one has a few jewels, they clean up and oil nicely. I am always amazed though at how dirty and full of debris most quartz watches I have worked on get, and still work.

Although it all looks a bit Heath Robinson, it works for me, and many watches have been saved from the scrap box.

The hand held oscilloscope you see in the picture was only £35 from amazon, works a treat. I do have an old CRT scope but have rarely been able to get a trace from an oscillator, I suspect too much internal capacitance.

Watch now running fine, it will have to wait for it's turn for a bit of wrist time.

 

 

[RichardHarris123]

Heath Robertson or not,  it works so kudos to you.