Vintage, speaking toy (Mattel, Pat Pat Rocket) died after about minute

[Kaleidocore]

Hello fellow engineers,

We managed to get our hands on an old (2008) Little Einsteins's Pat Pat Rocket toy for our 4-year old this Christmas. I had tried it a week before and it seemed to work fine; speaking, playing music, blinking the LEDs and reacting to the inputs. Sadly, after kiddo unwrapped the gift, it worked for approx. 30 seconds and then died. I tried swapping the batteries of course, but no luck - it's completely dead. No lights, no sound, no nothing.

I quickly opened it up to check for battery contact issues, loose cables or bad switches, but no such luck. The multimeter claims all the 3x1.5V get to the mainboard successfully when switched on, but absolutely nothing happens. The main board is fairly simple: a handful of components and the customary anonymous IC hidden under one of those dreaded black blobs. Nothing looks visually damaged or burnt, no bulging capacitors, etc.

I usually don't do electronics beyond the basics, and I'm trying to figure out if there is still life in this toy. What's the chance it's one of the replaceable components, like some capacitor or resistor? Or is the IC likely dead? Any easy checks I can do without unsoldering everything and without access to really cool tools? Or should I just give up?

Front:


Back:


Thanks in advance, and Merry Christmas!

 

[Martaine2005]

Looks like a lot of corrosion on the ‘back’ side. Probably traces have corroded and gone open circuit. You can clean the board with IPA to see if any damage has occurred and then fix the traces with small magnet wire jumpers across the open/broken areas.

Martin

 

[Kaleidocore]

Looks like a lot of corrosion on the ‘back’ side. Probably traces have corroded and gone open circuit. You can clean the board with IPA to see if any damage has occurred and then fix the traces with small magnet wire jumpers across the open/broken areas.

Martin

Wow, that didn't even occur to me! Will do, great tip! Thanks!

 

[Harald Kapp]

After cleaning the board:
Assuming the traces turn out to be o.k (they don't look too bad being covered by solder mask laquer) it sometimes pays to re-solder all solder joints. Add som flux. Lacking flux, add a little bit of fresh solder with a flux core.
Another source of problems can be the wires. Check each with a multimeter for continuity between the ends.