Electronics -PCB

[Mur Huwcun]

Have a childrens soft toy here that plays different song lyrics. It recently stopped working so ordered a new speaker for it. Unfortunately it’s still silent!! Had a look at the PCB, it’s got battery voltage, continuity for the speaker wires and every coloured pair is wired to a different switch for a different lyric. One of each pair is live and the other is energised by pressing the switch. Is anyone in the know about these things and if there’s anything else that I can do or test?

 

[jd6820]

Check bypass capacitors c1 and c2 for short circuit. Also assuming you are getting voltage between positive and negative? Not sure what voltage it operates at? 3v?

 

[Mur Huwcun]

Check bypass capacitors c1 and c2 for short circuit. Also assuming you are getting voltage between positive and negative? Not sure what voltage it operates at? 3v?

Yes voltage between neg and positive. About 4.2V (3xAA batteries) although I weirdly had 7.8v once Will check capacitors tommorow, I’m assuming I shouldn’t have continuity through them then?

 

[jd6820]

Yes voltage between neg and positive. About 4.2V (3xAA batteries) although I weirdly had 7.8v once Will check capacitors tommorow, I’m assuming I shouldn’t have continuity through them then?

Yeah no continuity through the capacitors. That 8 pin package looks like a voltage regulator so maybe you could find the datasheet for that and check the output voltages, that 7.8V doesn't really match a particular logic level voltage. Too high for 3.3 and 5V but too low for CMOS? Beyond that I'd say you are getting into more detailed diagnostics regarding input/output from the microcontroller....

 

[milkloss]

Is this one of those irreplaceable toys that is being missed? Been there!

 

[Dry Rot]

Surface mount? Best of luck! Can't even see the little suckers. I can test decent sized resistors, capacitors, and transistors when they are a respectable size. Do they bother with fusible links any more? Can of freezer spray for capacitors? A squirt of contact cleaner perhaps? I expect you're meant to throw it away and buy another one. Alibaba?

Here you go, US$7.37 for a sample, 14 day lead time, so a no brainer really. Then you can go for a minimum order of 3024 and stick the 3023 surplus on TFF classified.

Childrens Tune Playing Toy-Childrens Tune Playing Toy Manufacturers, Suppliers and Exporters on Alibaba.comOther Educational Toys

Childrens Tune Playing Toy Manufacturers & Childrens Tune Playing Toy Suppliers Directory - Find a Childrens Tune Playing Toy Manufacturer and Supplier. Choose Quality Childrens Tune Playing Toy Manufacturers, Suppliers, Exporters at Alibaba.com.Other Educational Toys

www.alibaba.com

 

[bravheart]

Oh well no one else said it yet so stock answer-
David King [emoji28]

 

[Mur Huwcun]

Is this one of those irreplaceable toys that is being missed? Been there!

Fortunately no but it is irreplaceable in another way as they don’t do any more!! It’s a welsh singing toy Seren Swynol!!

 

[Mur Huwcun]

Oh well no one else said it yet so stock answer-
David King [emoji28]

most probably they will hever have done a Seren Swynol!!!

 

[Mur Huwcun]

Surface mount? Best of luck! Can't even see the little suckers. I can test decent sized resistors, capacitors, and transistors when they are a respectable size. Do they bother with fusible links any more? Can of freezer spray for capacitors? A squirt of contact cleaner perhaps? I expect you're meant to throw it away and buy another one. Alibaba?

Here you go, US$7.37 for a sample, 14 day lead time, so a no brainer really. Then you can go for a minimum order of 3024 and stick the 3023 surplus on TFF classified.

Childrens Tune Playing Toy-Childrens Tune Playing Toy Manufacturers, Suppliers and Exporters on Alibaba.comOther Educational Toys

Childrens Tune Playing Toy Manufacturers & Childrens Tune Playing Toy Suppliers Directory - Find a Childrens Tune Playing Toy Manufacturer and Supplier. Choose Quality Childrens Tune Playing Toy Manufacturers, Suppliers, Exporters at Alibaba.com.Other Educational Toys

www.alibaba.com

It’s a welsh toy and the company can’t get any more!https://www.silwlicymru.co.uk/siop/y-seren-swynol/

 

[Dry Rot]

It’s a welsh toy and the company can’t get any more!https://www.silwlicymru.co.uk/siop/y-seren-swynol/

Not Chinese, but definitely foreign!

 

[towbar]

any chance somebody repaired and reversed voltage see red to black?

 

[Mur Huwcun]

Yeah no continuity through the capacitors. That 8 pin package looks like a voltage regulator so maybe you could find the datasheet for that and check the output voltages, that 7.8V doesn't really match a particular logic level voltage. Too high for 3.3 and 5V but too low for CMOS? Beyond that I'd say you are getting into more detailed diagnostics regarding input/output from the microcontroller....

Continuity through both capacitors C1 and C2 unfortunatel!!

 

[Mur Huwcun]

any chance somebody repaired and reversed voltage see red to black?

It was working ok then went a bit crackly then nothing, I just assumed speaker was gone!!

 

[SilliamWhale]

Job for David King Electronics!!

 

[cquick]

Whip those capacitors off and try it again. If you get continuity after removing the caps then the microcontroller is blown.
If you've got any regular through-hole ceramic capacitors around the 0.1uF mark, try adding one of them by soldering the leads on to the pads for those surface mount caps.
Try re-wetting the joints with good, old-school, juicy, lead-based solder.

That 8 pin package would be an EEPROM for storing the tunes for replay by the microcontroller. Can you read off any part numbers?

 

[towbar]

Continuity through both capacitors C1 and C2 unfortunatel!!

Disconnect battery when doing the test

 

[Mur Huwcun]

Disconnect battery when doing the test

That’s a good point!! Give me two minutes!!

 

[ACEngineering]

@Combine Rescue your in to electrics no?

 

[Combine Rescue]

I doub the capacitors get short but if you run them from battery dose caps don't really do a lot is only two IC there.
And usually that sort of toys are bullet proof, I have found one of them outside in garden wet and still buzzing after few years (regarding low battery voltage)
But is easy enough to put new set of battery.
Only thing I can think is the micro controller lost program or memory.
Is F.... like some other may said.

Anyway
DK electronics would not be interested in that...... since I left hehehe