- Joined
- Oct 6, 2014
- Messages
- 502
- Reaction score
- 21
I bought a wifi unit from a forum member here. It was toasted and would no longer output video. I opened the unit and this is what I found. None of components requiring heatsinks where touching the large heat sinking case. These components are secured to the board by "balling". Because of thermal expansion and excessive trapped heat in the component the balling would melt and the component lifts no longer doing its job.
If you have a vision 2+ and you want to save the wifi unit and make it last a long time, purchase some Arctic Silver and some copper shims and make sure your components are heat sinking properly.
I am going to try and reflow this unit and see if it can be brought back. More than likely it is fine and will be back in service, however its life span will be diminished from the excessive heat cycling.
I took a second wifi unit apart that has not yet failed and found a little better quality control. They used more thermal compound.
However once again I did not find any thermal compound on the final stage amplifiers. They are not supposed to exceed 85C but I found heat discoloration on the shielding above them. I usually only see this coloring when temps get above 400F. I decided that I would run additional heat sinking on these components also.
I tried different shim material and I wanted to find something conforming but did not want to use thermal foam. I ended up putting a bead of Arctic Silver thermal paste on aluminum foil and folding it to the right dimensions and thicknesses and then mounted it with paste on the components requiring it. I then added more grey Arctic Silver to the components that had minimal paste and applied better coverage and aluminum heat sinking material.
Of course while I had it open what better time to fix the GPS drop issue with more shielding. I dont think the GPS drop issue starts until the wifi begins to fail. I have caught mine in time. If you dont want your wifi module burning up you better do something about it.
Jeremy James
If you have a vision 2+ and you want to save the wifi unit and make it last a long time, purchase some Arctic Silver and some copper shims and make sure your components are heat sinking properly.
I am going to try and reflow this unit and see if it can be brought back. More than likely it is fine and will be back in service, however its life span will be diminished from the excessive heat cycling.
I took a second wifi unit apart that has not yet failed and found a little better quality control. They used more thermal compound.
However once again I did not find any thermal compound on the final stage amplifiers. They are not supposed to exceed 85C but I found heat discoloration on the shielding above them. I usually only see this coloring when temps get above 400F. I decided that I would run additional heat sinking on these components also.
I tried different shim material and I wanted to find something conforming but did not want to use thermal foam. I ended up putting a bead of Arctic Silver thermal paste on aluminum foil and folding it to the right dimensions and thicknesses and then mounted it with paste on the components requiring it. I then added more grey Arctic Silver to the components that had minimal paste and applied better coverage and aluminum heat sinking material.
Of course while I had it open what better time to fix the GPS drop issue with more shielding. I dont think the GPS drop issue starts until the wifi begins to fail. I have caught mine in time. If you dont want your wifi module burning up you better do something about it.
Jeremy James