I’d been wanting to fix my small clock for almost 2 years now but it was one of those things I kept putting off. The clock stops running at temps under ~50°F as I understand due to 2 old dried out capacitors. I purchased the capacitors from allelectronics.com 2 years ago along with some other components that I intended to use to retro-fit keyless entry to my 940. Anyway, the caps you need are 100uF 16V electrolytic (can style). Available at radioshack as well…
I thought I'd post my experience of fixing the clock while watching PBS.
*The most difficult, well, tedious part of the job was de-crimping the face ring on the clock. I just used a high –quality small blade screw driver and found a spot to wedge it under the crimp and the carefully worked my way all the way around. A little more finagling and the face will come off more or less intact.
*Remove the 2 screw from the back of the clock.
*Next you need to de-solder the ground connection to the case. You can see the connection on the back of the case: you’ll see large solder bubble surrounded by a small brass ring. Place the clock upside down, put a little pressure on the +12V terminal and then melt the solder bubble. The clock body should fall right out of the case.
*The two can-style capacitors on the clock are easy to locate. I found them easiest to remove by applying the iron to the joint and then pressing on the terminal w/ a screwdriver as opposed to pulling on the capacitor body.
*Almost done now. Install the new capacitors paying careful attention to polarity. Both the capacitor and the circuit board are marked. Apply the iron to the joint for a second or two and then flow a dab of solder into the joint… not the iron tip.
Now is a good time to test the clock if you have access to a 12vdc power supply.
Reassembly is pretty simple. Just make sure you force the clock firmly back up into the case when you are re-soldering the ground connection. I used thin piece of wood to protect the clock face as I gently re-crimped the ring with a needle-nose pliers. You dont need to re-crimp the entire thing, just in a few spots.
This tutorial would obviously be a lot better with pictures but I don't have capabilities or just haven’t taken the time to figure out how to attach or post them. I hope this helps somebody be on time!
Matt
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'90 245 244k, '93 945 225k
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