lcd trafalgar

[steveh]

hi folks

I bought 4 trafalgar NOS lcd watched off ebay, they've never been used. the terminals are clean, but there's no signs of life but for the lcd light coming on when pressed...any ideas's of things I cd try? they're in brilliant condition, but the lcd display is dead.......

be grateful for any advice, I can post some pics if it will help

thanks in advance

Steve
(glasgow, uk)

[Old Tom]

Lots of different modules in Trafalgar watches so pictures are required! Most commonly used in early models are modules from National Semiconductor- in both simple timekeepers and more fancy chrono modules. All suffer from the same faults- alkali "glaze" on circuit board, alkali penetration of circuit board and front polariser failure. If your display looks light/mid brown rather than dark grey the polariser has failed and needs replacing- your electronics might actually be working but without the polarisation you won't see anything. Anyway show photos please!

[steveh]

Hi Tom

thanks for swift reply, I've got four of them, been tinkering this afternoon, signs of life in 2 of them, the display came on but I think loose connection...as it faded away. You can see the display from an oblique angle...anyway, here's pictures, they're simple modules, just day and date...

Hope this helps

thanks

Steve

]

[steveh]

Well, the watches (all four of them) refuse to display, I don't think it's the polariser, I think its a connection problem, perhaps the carbon ridged strip that sits on the lcd panel? or would a faulty crystal be the culprit?

[Old Tom]

OK. Quite a late model Trafalgar with a cheap & nasty Hong Kong module (although they are actually very reliable). Probably needs nothing more than a good wash and contact to get it going again unless battery leakage has slipped under the resin covering the chip. The crystals rarely fail- have a look at the area between the crystal leads on the PCB (crystal side), frequently there is a largish "pile" of flux here that has become slightly conductive over the years, scrape it off and the watch runs! The zebra connectors rarely give trouble but always fit them back the same way as they were when you took them out- if you look closely you will see they have acquired a "flat" side, against the LCD, and a ridged side, against the PCB traces. Ridged side against flat LCD means missing segments.

[steveh]

Thanks Tom

that's really helpful, they are bottom end of the trafalgar range (they were only a bit more than a tenner on ebay, if I get one working its been worth it) When you say wash you mean spray contact cleaner?

all best and thanks again

Steve

[steveh]

Hi Tom

had a further tinker...signs of life, in the image below, the watch is working but you can only see the display from a very oblique angle, the battery is new....so polariser? if so where do I get from?

cheers

Steve