Quartz Analogue Clock from 80's model car

[Zarniwoop]

G'day all,

Recently the quartz clock in my car ceased to tick, or tock for that matter. I pulled it apart and cant see any obvious problems with the circuit.

It is made by Kienzle of Germany. It has an IC in there, markings on it are :

HBI04728AE
87749

There is also a large coil which runs the full length of the clock, I assume this drives the mechanism for the hands. This is connected to the PCB via two small posts, which must be de-soldered to remove the PCB from the rest of the clock. It should become obvious how this is assembled after viewing the pictures

Photos are included for your viewing pleasure.

I would like to know how to diagnose and pissibly fix whatever the problem is, since these clocks are frightfully expensive to purchase.

Cheers!
Grant


**broken link removed**
Coil

**broken link removed**
Bottom

**broken link removed**
Top

 

[Sebi]

This type of stepper motor run with polarity change in each sec. the rotor is a small magnet. Check the coil continuity with ohmmeter, the output with two antiparalel LED-s, the crystal with oscilloscope. I don't think the IC is bad.

 

[Zarniwoop]

Thanks for that Sebi, It looks as though the coil is to blame. Any suggestions on how to fix it? Is this a standard size coil which I could hope to purchase or make? Or am I all out of luck?

The coil appears to be connected to only one post, the other post is not electrically connected to anything.