Hi everyone!

Please forgive me if this question sounds stupid, admittedly I have very little knowledge of circuit boards and was hoping for some expert advice.

Last year I purchased a 12v ride on car for my daughter that could also be controlled via a remote control if needed.

Just before Christmas we decided to use to use the car again but Sadly it didn't work.

After checking simple things like battery and wires it appeared the main control board that controls speed/steering/rc was at fault.

I've hunted high and low since Christmas and finally managed to find the same control board that is needed - however this one is only compatible with a 6v supply.

my question is - is there anything that can be done to make it compatible with a 12v supply. I've attached images of the old control board for you to peak at. ( was unable to locate a schematic )




If it is only able to be powered with a 6v battery then I'll happily downsize from 12v to get the car working for her again, but I thought I would ask the experts first.

Many many thanks in advance

 

It may be worth taking a crack at fixing the board, the main suspects are the relays, very cheap, likewise the semiconductor screwed to the heat sink are prime candidates.
ebay 271047539370
Max.

 

I agree.. I'd fix the old vs trying to hack the new...

 

If its making a 6V one work from a 12V battery then you just need a regulator chip, or power it with a single 6v battery,

As for the faulty one, what's happening when it is powered up, description?

 

Thank you so much for everyone's input already. With regard to what's happened to the faulty unit - nothing happens at all. The resistors all seem to be intact and on close inspection I can't see any bad soldering connections. The board shows no signs of burning or have a burnt smell of any kind. It's just not putting any powe output to the motors etc. Do you think it would be worth trying to replace the relays as mentioned earlier. I'm able to purchase the 6v unit for around £10 if all else fails. I just also worry that the car might not have the sufficient power needed to function correctly.

Again, thanks to you all for your comments so far. Deeply appreciate it.

 

When relays or power semiconductor fail, there is not Always an obvious symptom, for a few $$'s I would try this first.
Can you see what is written on the semiconductor on the H.Sink.?
Max.

 

It won't be the relays, it's more than likely the large transistor on the heatsink or the RF module.

 

It won't be the relays,

That is not conclusive, for a couple of $ I would do it anyway, particularly in the case of someone that maybe has not the wherewithal to test them.
Max.

 

That appears to be a weird PCCT board, the power semi has small traces, the underside view has a strange devious way of routing the trace at the top right, it almost looks as though the mounting hole has opened the trace??
Max.

 

Hi Max,
I think you are looking at it "in negative" What you are viewing as tracks is the absense of copper.

Les.

 

Your right!
Max.

 

Hi all, thanks again for the suggestions and comments. I have purchased some semiconductors today and also the 6v version of the control module. As suggested by maxheadroom, for a few quid it isn't going to break the bank if it doesn't work.

Is there anything else that I could attempt to replace that might resolve the issue?

Out of curiosity, should the semiconductors not resolve the issue and I'm forced with 6v, would trying to enable that to 12v be a total ball ache? I'm guessing with such a leap in voltage a lot of the components would have to be replaced which would more than likely be way above my abilities lol

Many thanks again to you all

 

It might be as simple as a regulator for the microcontroller or control chip, the relays will probably be 6v coil rating and will work on 12V.

 

The question then is, will the solid state device picking up the coil be able to carry 2x the current?
Max.

 

When it does finally arrive will there be a way to check if it's capable of withstanding 12v without having to plug in a 12v battery and hoping it doesn't go bang ? Lol

 

I would not do it without a little reverse engineering to get an idea what is needed.
Max.

 

Have you checked that the 12 volts from the battery does not drop to very low value when connected to the car and when you do whatever is required to start the motor ? I have known SLA batteries to go high internal resistance so I think it is worth eliminating the batteries as the cause of the problem. Another way to test them would be to see if the voltage drops much when loaded with a car headlamp bulb or a 50w 12 volt quartz halogen MR16 bulb.

Les.

 

Hello everybody,
my replacement part finally arrived and I compared it to the old broken unit

After comparing the two, the only noticeable difference I can see is the board layout differs, the sanyou component has different numbers,the silver metal plate is smaller and the resistors have 16v written on them. I know it's a huge ask but looking from the images do you think attempting to use a 12v battery tomorrow would blow the unit or would it be capable of supporting it?

New unit


Old Unit



Many thanks to all of you

 

I have been looking into this for a while and apparently they use the same components for both the 12 and 6v models.

How did you get on in the end?