Viofo A119S V2 Supercap Exploding

[Nigel]

Those capacitors are poor quality. Any time a capacitor bulges and leaks its either under rated for power flow (6volts for 12volt circuit) or very old or counterfeit low quality copy (very common in China). That is a VIOFO manufacturing warantee issue create a Service Ticket and get a new Dashcam. If they won't do it let me know instantly.
From my A119S Troubleshooting Guide ...

Part E - Replace both Capacitors (STOP if had no experience solding)
1) with Dashcam back cover open gently detach Lens/Sensor Ribbon cable (less chance of scratching Lens)
2) remove 4 screws holding main circuit board to plastic frame.
3) gently lift top edge (sensor end) of circuit board to access reverse side of Capacitor solder joints.
4) draw diagram showing polarity of capacitors.
5) using 25 to 40watt soldering iron heat bottom joint then pull cap from opposite side to remove each wire. (experience needed)
6) trim new Panasonic FM 3300uF 6.3volt Radial Electrolytic Capacitors connector leads to same length as originals. (depending on cap thickness for bending over)
7) carefully solder each new capacitor, verify polarity position twice (warning: else caps explode)
8) verify new capacitors bend into flat position.
9) reassemble Dashcam
10) Test using Bare Bones setup in Part A

It is the supercaps that have the problem, not "Panasonic FM 3300uF 6.3volt Radial Electrolytic Capacitors "...

It would be a good idea to test the capacitance of the new super capacitors, especially if you are only replacing one. The most likely cause of a super capacitor explosion is that the two capacitors were badly matched and thus one of them got too much voltage. Cheap super capacitors can be very inaccurate in their capacitance value.

You can either test them with a capacitance meter / multimeter (but not all meters can manage multiple Farads), or connect them in series to 5 volts and measure their voltages (discharge them again afterwards), or measure their voltages after installation, the voltages should be roughly equal and well within their voltage rating (2.7v). It doesn't really matter what the capacitance value is, just that they roughly match so that their voltages stay within specification.

 

[BCHobbyist]

It is the supercaps that have the problem, not "Panasonic FM 3300uF 6.3volt Radial Electrolytic Capacitors "...

It would be a good idea to test the capacitance of the new super capacitors, especially if you are only replacing one. The most likely cause of a super capacitor explosion is that the two capacitors were badly matched and thus one of them got too much voltage. Cheap super capacitors can be very inaccurate in their capacitance value.

You can either test them with a capacitance meter / multimeter (but not all meters can manage multiple Farads), or connect them in series to 5 volts and measure their voltages (discharge them again afterwards), or measure their voltages after installation, the voltages should be roughly equal and well within their voltage rating (2.7v). It doesn't really matter what the capacitance value is, just that they roughly match so that their voltages stay within specification.

Thanks for correction, these SuperCapacitors are sold with different temp ranges and limited lifespans (1000 hours @ 70°C), I try to get highest temp versions (-25C<->70C).
KamCap 3.3F 2.7V SuperCapacitor -or- Nichicon 3.3F 2.7V SuperCapacitor, unfortunately Panasonic only makes the 3.3F at 2.5volts.

 

[SawMaster]

I must say that I've never heard of an unpowered cap exploding, but I've seen and heard many which let go on power being applied. With these wired in series I can see where the second cap could supply power, but what would complete the circuit if the cam were turned off? Very strange to me, but always looking to learn.

Phil

 

[BCHobbyist]

I must say that I've never heard of an unpowered cap exploding, but I've seen and heard many which let go on power being applied. With these wired in series I can see where the second cap could supply power, but what would complete the circuit if the cam were turned off? Very strange to me, but always looking to learn.

Phil

Hi Phil, come visit my workshop, 8 ft wall 8 ft wide racks of stacked 4-10year old motherboards removed from case, unpowered and CAPs randomly pop every month. They bulge and some leak while in the box. The worst are old PSUs unplugged but have charged 600volt twin CAPs, those don't blow but the smaller dried out one do all the time. Ask anyone in Tech Recycling Depots where they strip down computers and pile the circuit board in 4x4x4 bins, they pop all the time from old equipment.
It should NOT happen in a new dashcam. It won't cause a fire but could damage everything else close by and the leaking chemical will corrode the circuit board over time.

 

[Nigel]

I must say that I've never heard of an unpowered cap exploding, but I've seen and heard many which let go on power being applied. With these wired in series I can see where the second cap could supply power, but what would complete the circuit if the cam were turned off? Very strange to me, but always looking to learn.

Phil

I don't see how the 2nd cap could supply power, there will be no mechanism for transferring power between the capacitors connected in series.

Probably what happened was that they are supposed to have the same capacity, in which case they would each take half the voltage, so if 5 volts is applied across the two connected in series then they both take 2.5v which is less than their 2.7v rating so they are both OK. If one of them has less capacitance than it should then the voltage isn't spread evenly and the low capacitance one gets more of the voltage. If it left the factory charged to 3v then over time it could break down internally slowly producing hydrogen gas, and when there is enough pressure built up inside the sealed aluminium can, the safety valve (X punched into the top of the can) bursts open with a pop.

If that is what happened then replacing them with a new well matched pair will solve the problem.

It is not a common problem, not heard of any other instances for dashcams. Most of the supercap failures have been due to the plastic coating having a hole in it allowing the charged metal case to discharge into something it shouldn't, but when that happens they normally burst in a cloud of smoke when plugged in, due to one of the capacitors getting the full voltage, well above its limit.

 

[Lola]

It appears to me that Nigel and BCHobbyist have answered the problem (I sure didn't know), but the actual problem still lies with Viofo to fix (as BCHobbyist said) so I believe the OP should get hold of their Service department and send them a link to this thread.

 

[zs77706]

After Banggood will not replace or refund until they get a video from the popping sound, (that is not possible for nobody. Because we can not make a video from something what is happen in the past)

Now @viofo contacted me here in PN

They offered me a replacement after i send them the SN of my A119SV2

This is a very good Customer Service.

Thank you very much @viofo

 

[DarthMaul]

Glad to hear these manufacturers are taking care of their customers. Thumbs up!

 

[ljw2k]

Viofo have the best aftersales and never had any problems in the past.

 

[zs77706]

Yes, this was a big suprise from viofo for me.
this is a very good aftersales and customer service. thanks again