Voltage regulator getting hot

Hi there,

This time I’m the one asking for help. I’m building my 3rd console, with components I mostly bought on digikey and others I already had. The point is to test 130gF buttons instead of the 260gF from the kit. I also bought a better speaker. When it will be ready, I will give references from Digikey of the components I bought.

First problem I faced, I used a PN2222A transistor instead of a 2N2222 one. I forgot to check, the pinouts are inversed. But it shouldn’t impact my actual problem since the transistor is used for sound according to the schematic.

My problem is that when I turn the console on, the voltage regulator quickly gets very hot, so I turn everything off to prevent components from burning. I use this component, which is supposed to be the same according the build guide. I checked the components values, polarity. My solders look fine.

What else should I check?

Which Speaker did you buy? Your problem sounds like a short circuit, maybe there is a defective part?

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I use this speaker. The pinout is not straightforward because it has 4 pads. I used the leftmost and rightmost ones. I’ll check this later. For now I unsoldered it, and the problem remains.

I also thought about short circuit, but I see no solder bridge. I don’t like the new version of the screen you directly solder on the PCB, because it is a pain to remove to replace it or just check what’s underneath. I hope there’s no issue with the MCU holder.

It’s quite complicated to debug because I cannot turn it on. I’ll try to search for short circuits with continuity tests. This would be much easier with the eagle files of the PCB. I’ll end up making these myself. :slight_smile:

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@tom, please send us some photos of the PCB’s front and back.

Did you try testing your build for short circuits? Use a multimeter and check if there is continuity between the + and - pole of the battery connector. You can also test that between the - pole and the output of the regulator.

Also do take that transistor out, maybe it’s causing something unwanted.

  • Yes, the screen is a pain to remove but is still a much better option than the machined header because people were having lots of contact problems with that one.

  • The schematic is open-sourced but I will not release the gerbers or eagle files yet because I want to avoid loads of direct Chinese clones popping on ebay.
    In fact, the device is not that hard to copy and someone can easily make their own copy or a derivate of MAKERbuino’s design, but making money out of selling direct unchanged copies of something is a thing I don’t respect and will not let happen.

OK the fix was easy. The polarity of the JST connector for the battery was inverted. Usually the notch is on the top, I don’t know why it is the other way around on the console. I thought I checked the wires colors, but looks like I was wrong.
Also, to make things stronger, there are connectors with two metallic pads connected to ground on the sides. It makes 4 anchor points, which is much stronger and avoid breaking when connecting/disconnecting the battery. This is fine because we are not supposed to un plug the battery thanks to the charger though.

Now it is working fine. I still have to check the sound.

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I am glad that you’ve fixed this.
The cause for the polarity mistake is that JSTs from China have a reversed polarity compared to the ones bought from Europe.

I don’t know why it is happening, but it’s a reoccurring pattern for all types and models of JUST connectors

Thanks for the information. It might be useful someday. :slight_smile: