Frontier 2002, unknow led watch

[simone]

I just bought an unbranded led watch in NOS condition. Unfortunatly with fresh batt (2x357) the watch refuse to lights up so i replaced the crystal with no luck,still nothing, no life at all.
There was a minor acid leak near the trimmer (cleaned) but the module looks in very good conditions.
I just resoldered a little contact under the led display also (a bridge i suppose???).

Here the module pics, any tips?

IMG-20240129-WA0039.jpeg

IMG-20240129-WA0037.jpeg

Many thanks.....

[SASM]

From my point of view the module does not really look clean. The traces already have plenty of greyish discolouration and you can see the same effect around the display and also on the trimmer. That usually means that the wire bonds under the black coating are already damaged and the module is beyond (economical) repair from my experience.

Clean 2002 module usually have light(!) grey traces which do not change in colour.

Hanno.

[simone]

Thanks,
maybe a better clean?

Hanno do you have a working one to sell?

[Old Tom]

Hi,
The expert on all things Frontier is Ole Joe who used to work for them back in the LED days. Looking at your module there appears to be a link soldered across the two test pads below the display which shouldn't be there (check photos on google). The big Achilles heel of old Frontier modules is the laser trimmed oscillator bias resistor (the stepped black thing just above the display) which absorbs battery goop and goes low stopping the oscillator dead. I have never had any success in cleaning this part and used to end up removing crystal & associated components and replacing them with a tiny 32Khz oscillator chip and resistor.

[simone]

Thanks for the reply...
Well when i bought the watch i found a little metal bar soldered under the led panel but once cleaned the module it broke so i resoldered a little metal piece in the same place... So this part must be removed?
Second question is about the resistor you talk....what value? Where should it be soldered?Do you a pic of your repaired module?


Many thanks again