Old RC car, need help fixing Nikko Little Loader

[johnshepp]

Hey guys, i have an old RC car from when i was a kid and my kids are at the age where RC cars would be fun. I want to get it working again, it was working before it was packed away. So first off all there were no corroded batteries in the car so thats not the issue, i disassemble it and had a look for bronken wires and it seems to work fine. I have photos so maybe someone can help me check the components themselves to find anything broken or burned out etc.

Any help will be appreciated.

 

[Lightium]

Did you store it with batteries inside? If so or not have you tried first rubbing the contacts clean?

 

[johnshepp]

Did you store it with batteries inside? If so or not have you tried first rubbing the contacts clean?

it was stored without batteries inside, have not cleaned but i messured that it gave the correct voltage out of the batterie holder.

 

[Lightium]

It worked fine before storage? How long ago was that. Only thing I can think of is that one or a few of the electrolytic capacitors have dried out.

 

[johnshepp]

It worked fine before storage? How long ago was that. Only thing I can think of is that one or a few of the electrolytic capacitors have dried out.

Well something like 25 years in storage, so i could not have worked but i believe it did. It is probably from one off my older siblings so could be 1 years older (35 years).

Is it possible to test the electrolytic capacitors with a normal multimeter and oscilloscope?

 

[JimB]

Looking at the photos, there appears to be a couple of date labels, 1-06-86, so the thing could be 40 years old.
In that time any of the active components could have been subject a random failure.

Electrolytic capacitors?
Would not be my first suspect.

Is it possible to test the electrolytic capacitors with a normal multimeter and oscilloscope?

The quick answer is no, the longer answer is maybe.

Some multimeters can measure capacitance, but to do that the capacitor must be disconnected from the circuit.

One of the failure modes of an electrolytic capacitor is high ESR (Equivalent Series Resistance).
This can be measured with an oscilloscope, but you also need a function generator.
Look here:

If your oscilloscope can display up to 27MHz, it may be possible to test the transmitter, so giving a better idea of where the fault may be.

JimB

 

[augustinetez]

Most likely the crystal in the transmitter is DOA - common fault for them.

Frequency is 27.145MHz, you can test by putting the transmitter near a radio tuned to the crystal frequency and listening for the signal.

 

[johnshepp]

Looking at the photos, there appears to be a couple of date labels, 1-06-86, so the thing could be 40 years old.
In that time any of the active components could have been subject a random failure.

Electrolytic capacitors?
Would not be my first suspect.


The quick answer is no, the longer answer is maybe.

Some multimeters can measure capacitance, but to do that the capacitor must be disconnected from the circuit.

One of the failure modes of an electrolytic capacitor is high ESR (Equivalent Series Resistance).
This can be measured with an oscilloscope, but you also need a function generator.
Look here:

If your oscilloscope can display up to 27MHz, it may be possible to test the transmitter, so giving a better idea of where the fault may be.

JimB

Thanks alot for all the info. I have two oscilloscope's i will have a look if they can do what you suggest (27MHz).

 

[johnshepp]

Most likely the crystal in the transmitter is DOA - common fault for them.

Frequency is 27.145MHz, you can test by putting the transmitter near a radio tuned to the crystal frequency and listening for the signal.

Haha that is a simple solution, i like it. I will see if i can find a radio that goes that low or can i use any radio, and/or can i use any frequency?

 

[Les Jones]

Have you checked the batteries in the transmitter ? Does the transmitter draw current from the batteries when it is switched on and any of the controls opperated ?
Les.

 

[johnshepp]

Have you checked the batteries in the transmitter ? Does the transmitter draw current from the batteries when it is switched on and any of the controls opperated ?
Les.

Thanks Les. I will check this.

 

[augustinetez]

Haha that is a simple solution, i like it. I will see if i can find a radio that goes that low or can i use any radio, and/or can i use any frequency?

The radio has to be able to tune the actual frequency of 27.145MHz.

 

[liamjerr]

Looking at the photos, there appears to be a couple of date labels, 1-06-86, so the thing could be 40 years old.
In that time any of the active components could have been subject a random failure.

Electrolytic capacitors?
Would not be my first suspect.


The quick answer is no, the longer answer is maybe.

Some multimeters can measure capacitance, but to do that the capacitor must be disconnected from the circuit.

One of the failure modes of an electrolytic capacitor is high ESR (Equivalent Series Resistance).
This can be measured with an oscilloscope, but you also need a function generator.
Look here:

If your oscilloscope can display up Car Shakes to 27MHz, it may be possible to test the transmitter, so giving a better idea of where the fault may be.

JimB

Common problems include battery or power issues, worn-out gears, malfunctioning remote controls, or damaged wiring. Begin by inspecting the battery connections and ensuring the battery is fully charged or replaced if needed.