Nelsonic Pac-Man game watch faint sound repair

[sideburn]

Hi all, wondering if anyone can give me some tips on this one. I’ve managed to get this old 80’s PacMan watch working after cleaning up corrosion on the battery terminals but the sound is so faint I have to smash the watch up against my ear to hear it. There’s what looks to be two tiny FETS, a tiny capacitor, and what looks to be a variable capacitor on the board and the traces go to the springs that touch against the piezo speaker element. I thought maybe it was the cap and maybe adjusting the tiny pot/variable cap would be the culprit but Adjusting the variable pot made no difference. I tried putting a ceramic cap in place of the fixed cap and that did nothing. It wouldn’t even power up. I’ve attached a pic of the pcb. If anyone had any ideas please let me know. Thanks.

[sideburn]

Well I have since learned from this site: https://www.explainthatstuff.com/quartzclockwatch.html that what I thought was a tiny capacitor is actually the quartz oscillator. I did make small adjustments to that pot thinking it would effect the sound volume but what I might have done is alter the rate of the oscillator maybe?? Not sure. So far not is keeping correct time still so I am not sure what that pot is for.

As far as further troubleshooting the low sound problem, I am now thinking maybe it is those FETs but not sure what type they are or anything. Or maybe its that round choke/coil looking thing.

[sideburn]

Wow I can't believe I just fixed it!
I took it back apart and re-flowed the solder on the tiny FETS and that choke/coil and bam perfect sound, loud and clear!

[Bashstreet]

Wow I can't believe I just fixed it!
I took it back apart and re-flowed the solder on the tiny FETS and that choke/coil and bam perfect sound, loud and clear!

Another dicky connection sorted 

[coromonadalix]

Be sure to clean the pcb properly 

[sideburn]

Yeah, now I really believe in the “bake it in the oven” fix trick.

[chuckyab]

Hi, I have a first edition pac man nelsonic. Nothing happens when I put in a new battery. Is there a page with instructions on how to get this back to working? A website, or youtube video? Thanks for the help