Dash Cam keeps rebooting

[jammygit]

Well it's been a year since the last post and this wasn't resolved, so I have dug mine out of a cupboard and taken it apart. The battery was completely flat and wouldn't charge. So far I have de-soldered the battery and discharged/charged it with a professional battery charger. The battery is full @ 4.2V and took 342mAh of charge out of it's claimed 400mAh, no not too bad. Will update ones put back together.

 

[kamkar]

Normally when lipo batteries have been below 2.8 volts then they are a write off, but this might be another type, or it never got that low in voltage anyway.

 

[c4rc4m]

If putting a new battery in it didn't solve the issue then I would guess it's a heat issue. Maybe it has a heatsink that has come away from / no longer properly seated on the processing chip and is causing it to reboot? That would be a typical PC scenario as many processors have thermal protection built in and will simply reboot when the pc hits desktop due to thermal overload if the thermal compound has come away or become loosened allowing air underneath, as booting itself is CPU and thus heat intensive.

Wondering if it got knocked or dropped or just handled roughly and if this could have caused any heat sink separation?

It's very difficult to guess not knowing the internal layout of the individual cam and whether or not it requires / has heatsinking. However, if you previously fitted a new battery, that really rules out a battery issue. BTW a flat battery after a year of storage is not unusual. Batteries discharge slowly over time without use. That's perfectly normal.

Another guess might be the breakdown of some sort of voltage regulator allowing over voltage / heat.

However, at the end of the day, these are just guesses. You'll only really know if someone with the correct knowledge can get inside and analyse it. That would probably be the manufacturer and something that would cost far more than the cam is worth in postage alone.

I think my advice would be leave well alone - be careful with lithium batteries as they can explode if not charged at the correct rate. Might be better to simply move on and buy a better solution and write the brand off to experience.

 

[jammygit]

I've had the board under a microscope and I can't see any blown components. It's almost certainly a power issue, my gut tells me a bad capacitor, but they're bloody microscopic. I'm going to leave it at that for now because I can't be bothered. I think it would be worth solving the issue because it's probably quite common with many people saying it's failed after x months. I also hooked it up to a fully charged 18650 3.7V 2000mAh battery and it still rebooted just the same.

Also, it doesn't matter how long you leave the unit plugged in, the battery never charges. Another possible indication of power issue.

 

[Sunny]

Does it reboot if you don't have MicroSD card in the slot?

 

[jammygit]

Does it reboot if you don't have MicroSD card in the slot?

Yup, with and without.

With it plugged into a USB supply, it just continuously reboots. When on battery and switched on, it just shows the Welcome screen and then switches off.