please help to fix a toy

I’m trying to fix my niece’s toy vending machine.

How it works:

• Machine trigger neither by fake coin and credit card (the motor push the lever then it hit the stop switch which stop the motor). But when trigger by fake paper money then the motor will keep turning about 4 seconds after the stop switch was push.
• Once it triggered then you can press 3 buttons at front to release the fake drink.
• It have voices when start, triggered, sleep and button pressed.
• Use 4AA battery in parallel supply 2.7v at the moment.

The motor not turning when triggered. Tried to replace the motor but the same. Tested both old and new motor working just fine with 3V power. I meter the motor wires and it said 2.5V when triggered. Reattached the old motor and found if I spin the motor with my fingers then it will turn until I push the stop switch.

PCB board have a ceramic capacitor in M+- under the board same as the one in the motor. Also, another small capacitor on top of the sealed IC under the board.

I’m a newbie in electronic. After searching the web, I’m guessing the 2 three legs components are resistor transistor and do as a switch. Am I right? Any idea how to fix this things? Thank you all.

okaydoke said:

2 three legs components

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Those would be transistors with a resistor between them.

If the motor is not triggered, the problem is in the triggering device. There is some calibration that needs to be set, some short, some component burned or some processor to be programmed.

Four AA batteries in parallel should NOT be 2.7v!! Are you sure it's not a series/parallel setup?

NsrMagazin said:

If the motor is not triggered, the problem is in the triggering device. There is some calibration that needs to be set, some short, some component burned or some processor to be programmed.

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Trigger is working, only the motor not turning. But when I spin the motor with my fingers after triggering the toy, motor will start turning as it should.

KevinW said:

Those would be transistors with a resistor between them.

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Thanks for correcting me. Yes, they are both transistor. I assume one is for coin and credit card. The other for paper money because the 2 different mode to tell the motor how long should it turn.

hyedenny said:

Four AA batteries in parallel should NOT be 2.7v!! Are you sure it's not a series/parallel setup?

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They are old battery. When I put in new battery the toy have some weird noise when trigger. Before the motor have problem, No weird sound with new battery. I didn't check the voltage with new battery, will check it tonight when home.