Retro 'Game Boy' key ring watch - REPAIR

[Pete.M.B.]

Hi all.

First time here, so not sure if I'll get the answers I'm after, but here goes.

I'm looking to refurbish/repair this old novelty 'Game Boy' styled keyring watch, from the early 90's
- PLEASE SEE PICTURES -
After almost 27 years of no use, when I name to put an old battery in - to test it - it worked, amazingly.
Then, when I took the back off again to actually put a new battery in, it didn't work????

This had me stumped, but what I noticed was that on the 2nd time of opening it, the two little yellow "pads" - PLEASE SEE PICTURE - that were stuck to the back of the tiny LCD display, pretty much crumbled to dust in my hands, at the gentlest of handling. I suspect that what ever material these were made of, had simply perished, due to age?.

So my questions are thus:
1: What were these pads likely made of, and what is/was their purpose?.
2: Can I replace them?.
3: Is it likely, that as these are now absent, is why it doesn't work anymore?.

It should be noted, this is very simple little digital watch in the shape of the classic Game Boy, I refuse to believe it cannot be fixed , but of course I know ZERO about electronics, so....

I know this is probably an unusual item, but any help would be gratefully received.
Having tried electrical hardware stores, I've had no luck.

 

[Harald Kapp]

Those pads were probably self adhesive to stick the LCd to the PCB.
Between LCD and PCB I'd expect you to find one or two strips of zebra connectors (link).
The adhesive pads would attach the LCD to the PCB and the zebra connectors would make the electrical connection. Without either chances are the electrical connection is from vbad to non-existent.
The pads can be replaced by two-sides sticky tape of similar thickness, provided the tebra connectors are stilll present and at the correct position(s). If the zebra connectors were lost it will be rather difficult to find a matching replacement (short of disassembling another watch of the same type).

 

[Pete.M.B.]

Hi Harald.
Many thanks for your detailed reply. Bless you for taking the time to explain what you feel might be the problem.
OK, well attached is the picture of the tiny PCB that the goes facedown inside the plastic casing, and butts up, behind the little LCD display.

That top part of the PCB, where that Black blob is - sorry don't know what else to call it :/ - is where the yellow perished pads touched?.

I don't see any "zebra" connectors (yes I checked the link you supplied) and the pads were just a solid Mustard Yellow colour, no "zebra" markings on them, as per the Link.

Any other ideas, now that you've seen the PCB?.

Many thanks again, Harald.

Pete

 

[Harald Kapp]

The zebra connectors should contact the pcb on the pads marked red:

Maybe the connectors are part of the LCD assembly? Could it be you lost them when opening the watch?
Without a connection between LCD and PCB the watch can't display anything.

where that Black blob is - sorry don't know what else to call it

"Blob" is o.k., This is epoxy to cover and protect the integrated circuit underneath.

 

[Pete.M.B.]

Thanks for your continued assistance with this, Harald.
Well I certainly wasn't aware of "losing" any components, when opening the back up?.
As I say, the only thing that was evident was the crumbling yellow pads.

Regarding the "connectors being part of the LCD display" well, they weren't as far as I could tell.
The picture of the back of screen - that I sent in the first post about this - were the only things touching the back of the LCD.

OK, so moving on; What If I was to buy something like this LINK: http://www.youeal.hk/en/products/conductive-silicone-zebra-elastomeric-connectors/
Would that not fix the problem?. Would it not connect the PCB to the LCD, which is what I need?.

Many thanks again.
Pete

 

[kellys_eye]

zebra strip is sized to suit the gap - not all pieces will fit.

Can you show a picture of the LCD side? Maybe the strip is still adhering to the other part of the unit? They are commonly in a molded plastic 'slot' anyway.