Is this Trafalgar/Litronix Hopeless?

[Bad Juju]

I have a Trafalgar and I am not sure if there is any hope for it. The module reads:

SINGAPORE LITRONIX
NO (0) JEWELS UNADJUSTED

When I put batteries (357) in it I get activity but it ranges from cycling through the days of the week to weird flickering back and forth between the left two digits and the right two digits to cycling through the days of the week with gibberish inbetween. Is there anything I can do?

[J Thomas]

[Led-Time]

Don't these modules have strange three wire crystals in them I remember trying to get one going a while back without success, good on you if you get it going...

[Bad Juju]

I've done a bit of soldering in my life and I'm not afraid to attempt a repair on an inexpensive watch. But, where is the QC? Is it the part at the top of the module in the first pic? that doesn't look like the QCs I've seen before. It looks like a tiny flat piece of glass (crystal?).

[J Thomas]

[retroleds]

Jeff:
I agree with all of this, except the 2 leads parts. They have 3 leads on the early ones, as they needed 1.5 volts tto "excite" them into oscillation. Unfortunately, they are also an odd capacitance. I was doing business with a guy who has worked at Statek for 30+ years(neighbor of Guy Ball, founder of ledwatches.net)) and I got some of this from him. He was only able to supply me with the next generation crystals(2 lead), which didn't work for squat, due to the capacitance difference.

[J Thomas]

[retroleds]

Jeff:
I have a handful of those the guy sent me...vinrtually identical, with the little "glass" window. I hadn't heard much about the process used to trim/adjust those crystals - wow! It's a shame that more history isn't posted on the Statek site.

Here's an article about Statek
http://www.ledwatches.net/articles/Statek%20Corporation%20-%20Watch%20Crystals.htm

[J Thomas]

[Bad Juju]

So, I can't use just any 32 Khz crystal?

[retroleds]

So, I can't use just any 32 Khz crystal?

Unfortunately, no.

[Bad Juju]

Any ideas where I can source a correct crystal? Is it cost prohibitive?

[digibloke]

I don't think your watch needs a new crystal - if it did it would probably be dead or just showing one digit at a time. Also I don't think these bubble display litronix modules take 357's - they more often than not take 386's. The extra pressure from using cells which are too big could be causing it to play up or - worse - you might have cracked the circuit board.

If using 386 batteries doesn't help then the next thing to check is all of the metal connections to the batteries, pusher contacts and case from the module. Bare in mind that once you've got the plastic case off (front first) you have a lot of exposed wire bonds so you have to be very careful.

On a litronix module the contacts are all just "clipped" onto the circuit board and they can become loose and lose connectivity over time. You can see in the battery wells that there are two connections to each cell - these all need to fit snugly to the board to work. You can either take them off and gently tighten them (then replace them) or you can put a small amount of silver epoxy between them and the board to make the connection. Remember there are two for each battery, one for the command button, one for setting and then one which makes a connection beween the module and the case.

It's very fiddly and it may be something completely different like a logic problem or a short caused by battery leakage but it's worth a try if you've got the time/patience.

[Led-Time]

I don't know about the Litronix module/Trafalgar set-up but on Litronix watches the module has a connector on the side which touches on the inside of the case make sure this is also clean check the case too, has your watch got what looks like a thin rubber disk covering the batteries when the case back is fitted Litronix watches has this too.

In all truth these are not the best modules ever fitted inside an LED watch if they run then great but from past experience non workers usually get chucked in the spare parts box after much cursing and swearing...

[Bad Juju]

I don't think your watch needs a new crystal - if it did it would probably be dead or just showing one digit at a time. Also I don't think these bubble display litronix modules take 357's - they more often than not take 386's. The extra pressure from using cells which are too big could be causing it to play up or - worse - you might have cracked the circuit board.

I don't think I have caused any pressure damage as I did not put the back on the watch. The negative connectors are on the bottom of the battery wells and the positive connectors are on the sides. I will try the 386s. If that doesn't work I will start delving deeper.

I don't know about the Litronix module/Trafalgar set-up but on Litronix watches the module has a connector on the side which touches on the inside of the case make sure this is also clean check the case too, has your watch got what looks like a thin rubber disk covering the batteries when the case back is fitted Litronix watches has this too.

It sounds like this module is just like the ones in the Litronix watches that you describe. There is a tab that touches the case (ground?). It has a thin disk but it is a thin foamy material... much like I have seen stereo equipment wrapped in but thinner. I will clean all contacts when I try the 386s and see what happens.

I'm not cursing and swearing yet.

[J Thomas]

[retroleds]

Ok, I just got back from a very brief vacation, so i decided to take a look at this thread again. Thoughts:

The top left picture of original post - the negative contact in the battery well on right side is obviously lose or been pushed around. The Litronix module is really particular about battery contact all the time, to both wells, as the thrid leg of that crystal has to be front loaded with some voltage. If you take the front off the module(stay away from the wirebonds, leave plastic magnifier over display if it stays attached), you will see the side contacts are all just pressed onto the edge of the board. You can scoot them over and clean the area with a small wire brush, but then the choices are(a) solder which doesn't stick real well if the contact pads look like aluminum; or(b)silver epoxy, which sticks decently but has very poor physical strength.

To test it out of the case. The contact that touches the case is either up at the 12:30 position(right above time command button) or at about the 6:30 postion. you can put a small clip on it and while holding two batteries in the well, touch the other end of the clip to the time command contact to test function. Unfortunately, the setting procedure for some of those modules requires two buttons held down simultaneously, so it become challenging to test those functions out of the case. Another really important consideration - many(not all) Litronix modules, like virtually all TI(Texas Instruments) modules, don't actually run until you have set them. This was so they could be shipped with batteries in.

[bucko170]

I was able to modify a 29mm Hughes module to work in the place of the defunct Litronix module in my 'Trafalgar' watch.
Just a thought.

[LEDluvr]

The Hughes modules are the way to go IMO.
Durable, reliable and (relatively) plentiful.
Not to mention affordable....

[bucko170]

The modified Hughes module looks better than the original Litronix module IMHO, it's also easier to read the display when viewed at an angle without the magnifiers over the digits.