WANTED: Xernus / Sunrex 8110 Alarm Crono' Module or Watch

[Seiko7A38]

Bit of a long shot, this, but if you don't ask ....

I'm looking for a good working Sunrex 8110 module, or beater Xernus LCD Alarm Chrono' (the tattier the better), with a working module.

For those of you who've never seen one out of the watch, it looks something like this from the top:



And like this from the underneath (with the insulator removed) and ideally without the verdigris.



Module is approx 31.0mm Ø and 3.0mm thick, with 4 pusher contacts. It uses a RW40 / 391 sized battery.

[Seiko7A38]

I'm looking for a good working Sunrex 8110 module, or beater Xernus LCD Alarm Chrono' (the tattier the better), with a working module.

A Xernus LCD Alarm Chrono using the Sunrex 8110 module would look very similar to this model (but without the 'solar panel'):

[Old Tom]

That module would probably clean up very succesfully using an acid/bicarb/water/alcohol set of washes. I find that about 75% of LCD modules in a similar state do work after this treatment- worst problem is that the negative contact finger has turned to brittle blackness which means a hunt through the old parts box(es!). You have to dismantle the module completely to do this. don't just dunk the whole thing. If you cannot find one then well worth trying.

[Seiko7A38]

Thanks for the advice, Tom. In fact, I was one step ahead of you.

I'd already stripped the module yesterday.

The PCB cleaned up quite nicely using ElectriCor VCI238 aerosol spray (akin to WD40), and gentle probing with cocktail sticks.
There's some minor collateral damage around the resistors near the battery contacts:



But as you correctly assumed, the -ve battery terminal was toast; it's imprint remained only as verdigris:



I don't have anything in the way of an LCD 'bits box', so as a first attempt I'm going to try to fabricate a new -ve terminal from an M4 solder tag.

This want ad is a 'back-up plan', in case my unqualified (LCD-wise) efforts fail.

[Seiko7A38]

It's interesting what you notice from looking at your own hi-res photos ....
.... (apart from the odd bit of verdigris that you missed cleaning off )

A Xernus LCD Alarm Chrono using the Sunrex 8110 module would look very similar to this model (but without the 'solar panel')

Looking at my first photo again, the 8110 module plastic spacer actually has a moulded recess to take the 'solar panel' below the LCD display:



I wonder if they might have shared the same (but lightly modified) PCB ?