The unit needs to be removed then disassembled and all the solder joints on the circuit board re-heated and set again with a soldering iron. Aparently the solder being as old as it is has contact problems. I discovered this from a nissan patrol forum and it fixed my patrols clock, so thought Id give it a go on the gazelle clock and it fixed it too.
To get the clock out of the dash: pull out the shroud thats just clipped in, which then reveals two screws that hold the clock in. Unscrew the screws, disconnect the plug at the back, and its out. The clock has a couple of tabs on the top and bottom which once depressed allow the face to come away from the body and now you can see the circuit board inside. You will have to release the plug from its holder and then the circuit board will just lift out. Installation is a reversal of these steps.
I avoided the screen and microchip solder points and only resoldered the power wires, capacitors, resistors, etc.
And use a low watt soldering iron. It only takes a second to melt the small amount of solder.
So there you have it, dont put up with a clock that works sometimes and other times wont, took me about 1/2hour to do it, if you can handle a soldering iron its a piece of piss.
Edited by redgazelle, 25 June 2010 - 09:12 AM.