Viofo A139 3CH review

[Nigel]

I want to warn you that some chips are under voltage from supercapacitors!!
Therefore, when removing screen covers, be very careful and use a plastic tool!!

Good advice, maybe sensible to discharge the super capacitors; if you do then make sure you discharge both properly before powering the camera again.

 

[vvs49]

I usually cut off one lead at a time and then solder them, it’s easier for me!!

 

[jackal2001]

I want to warn you that some chips are under voltage from supercapacitors!!
Therefore, when removing screen covers, be very careful and use a plastic tool!!

Thanks. I don't know if there is any way to improving cooling since everything is jammed in there. I was going to take a look at the heat sink, maybe remove it and reapply CPU thermal compound and/or maybe look for a copper shim online to sandwich in between the CPU and heatsink. I don't know if I want to waste the time and effort.

 

[jackal2001]

I usually cut off one lead at a time and then solder them, it’s easier for me!!

Why are you cutting them off? Sorry for the dumb question. If I were only to play with the heatsink why not just leave them alone?

 

[vvs49]

Why are you cutting them off?

I exclude accidents, I had experience, I also dealt with a radiator, I took off the cover and shorted it in the board, a spark jumped and 139 died, I had to repair it!!
There is a gap between the processor and the radiator, I put in a copper gasket 0.8 mm thick.
But that was a long time ago, maybe viofo has already changed everything in the design!!??

 

[Nigel]

I usually cut off one lead at a time and then solder them, it’s easier for me!!

There is still power in them if you just cut a lead, they can still cause damage.
If you short the pins for a few seconds then there is no power left, so they are safe.
Ideally short them through a resistor, and do both until there is no power left.

 

[vvs49]

There is still power in them if you just cut a lead

I don’t cut the wires, but the terminals of the supercapacitors, they no longer power the board!!

 

[jackal2001]

I exclude accidents, I had experience, I also dealt with a radiator, I took off the cover and shorted it in the board, a spark jumped and 139 died, I had to repair it!!
There is a gap between the processor and the radiator, I put in a copper gasket 0.8 mm thick.
But that was a long time ago, maybe viofo has already changed everything in the design!!??

Ya I think I saw that in this thread and since it was discussed , viofo said that was not a production model when the heatsink wasnt touching the CPU.. I don't buy it at all. So they intentionally made something that was going to overheat? Riggghhhtttt.

I was looking at doing the same type of mod but didn't get to pry the board out yet. Got a little nervous about trying to pry it out without damaging anything.

 

[vvs49]

Got a little nervous about trying to pry it out without damaging anything.

Don't forget to pull out the card, otherwise there will be trouble!!

 

[jackal2001]

Don't forget to pull out the card, otherwise there will be trouble!!

Right. How does the heat sink attach? Is it screwed down, thermal glue, thermal paste, etc? I have thermal paste from PC builds over the years but I don't think that will be strong enough on its own unless the plastic shell casing squishes it or something

 

[joe384]

When I was having issues with my A139 overheating I wondered whether an external fan blowing air on to the grill would help.

You could mount the fan to a custom bracket and then use the screw holes to mount the bracket.

If I had a 3d printer I'd be tempted to make a fan duct that held the fan and attached on the screws (meaning I wouldn't had to drill or cut the case)

 

[jackal2001]

When I was having issues with my A139 overheating I wondered whether an external fan blowing air on to the grill would help.

You could mount the fan to a custom bracket and then use the screw holes to mount the bracket.

If I had a 3d printer I'd be tempted to make a fan duct that held the fan and attached on the screws (meaning I wouldn't had to drill or cut the case)

Uh no

 

[jackal2001]

Got it apart but I don't want to start prying stuff.

 

[Nigel]

I wondered whether an external fan blowing air on to the grill would help.

A small amount of air blowing over the case probably makes a big difference, no real need to blow it through the case, and you won't need much air.
If you blow the air across the front rather than into the front, then you will suck the hot air inside the case over the heatsink and out of the case.

Got it apart but I don't want to start prying stuff.

Missing some solder from one of the super capacitor legs?
Doubt that it is a problem, just looks odd!

 

[jackal2001]

A small amount of air blowing over the case probably makes a big difference, no real need to blow it through the case, and you won't need much air.
If you blow the air across the front rather than into the front, then you will suck the hot air inside the case over the heatsink and out of the case.


Missing some solder from one of the super capacitor legs?
Doubt that it is a problem, just looks odd!

I'll touch that up. I don't think I need to discharge them as long as I don't cross + and -

 

[jackal2001]

Well I'm done. I touched up the legs of the capacitors. I removed the dust filter from the side that faces the cabin and I tried to break out some of the slots at go up against the windshield for better air flow.
Powered back up fine.
The only way I would attempt to tear it completely down is if I had another working unit.