Backlight stopped working after analogue battery change

[Subotai]

Hi guys, first post and not sure I'm in the correct place. I have a few dual time (analogue and digital) watches that need a new analogue battery (the digital part works fine) but on changing the backlight for the digital part no longer works. I had a jeweller change one and the backlight would not work after he changed the AG4 either. I searched around and found comments about re-sets, but these seemed mainly with issues of the digital no longer working and reference a reset 'point'. I have now changed the AG4 only (the CR1620 is good) on another and the backlight which was working before the CR1620 was removed to get to the AG4 no longer works. The digital part is working (stopwatch, alarm etc) just not the backlight. The latest is made by 6.11 (other two were Jedir) and its instructions only states to replace a battery when needed. There is no AC as I have read but one has a BUZ circle. I have put one end on my steel tweezers into that and held it on the watch side, the CR digital battery, the case, another piece of metal and nothing gets the backlight working again. This one had a spring that touches the case and I made sure to fit the case in the exact way I removed it. Anyone have any idea what else I could try please? If the backlight didn't work at the start I'd guess it was the lighting part itself but as they worked before taking it apart to fit the AG4 battery, I'm completely stumped. The Jidir ones had no spring when the backs were removed and they too had no issues with the backlight until the AG4's were changed.

I'd really appreciate any help and advice anyone can give.
Thanks
JJ

[JohnD]

Every time that I have found a digital/analogue watch with the digital bit working but the analogue not, it has been because of physical damage to some part of the analogue circuitry, usually the coil, due to a ham fisted battery change in the past......

[Subotai]

Hi,

Thanks for the reply. All battery changes have been their first. On checking, the AG4 is dead as a door-nail but all the digital part works fine and the battery has a good amount of power left. Once I remove the battery for the digital so I can access the AG4, put it back together very carefully, the analogue works fine, the digital works all but the el backlight.

[watchweasol]

Hi   not a lover of the cheap AG  alkaline batteries the Renate silver oxide batt is  SR626 or SR626W.  As John D remarked  when watches dont work after battery changes is either it was DOA and a battry will not revive them of If  recieved in a working state and after a battery change they dont work its usually some mishap that caused the problem.  The spring on the green module is for the pizo alarm buzzer, Can you remove the green module and post a photo of the analogue movement please.

[Subotai]

I'll get that photo taken later. Would that have any bearing on the backlight? As mentioned, it was working until I removed the CW1620 so I could get to the analogue battery. 

[watchweasol]

Hi  I reckon the problem is somthing has happened during the removal of the 1620 that has renderd the backligt faulty.  Is the bak light a small bulb if so where and how is it connected, are all questions to find answers to.

[Ramone]

Hi I know this is an old post 

Today I changed the analogue battery on the same watch, when I put the watch back together, the backlight stopped working as mentioned, 

To change the analogue battery you have to remove the circuit 

What I've discovered upon opening it up again is two black conductive " rubber " strips that complete the circuit for the light, they are small rectangular shape and fit in holes vertically,  when you lift up the circuit, they get misplaced as sometimes they stick to the underneath, 

When I replaced them, the backlight was working again, it's also a good idea to clean the surface that makes contact with the board with some rubbing alcohol 

Hope this helps