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DogMods

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Reply with quote  #1 
Hi everyone, I have been having an issue popping what I consider to be an abnormal amount of on board fuses. I love the chipset so far, think its great, but I'd like to get to the bottom of this. I am open to any feedback, ideas, etc.

I am thinking my issue may be similar to what the Opus is experiencing lately as my board mounting solution grounds the board to the enclosure, and thus the 510. So far, the only thing I can think of is that this is being caused by Atty shorts which occur for a split second and pop the fuse, but I may be totally wrong. In an attempt to rectify this I am also going to start flowing a small amount of insulating epoxy around the base of any wires to ensure they are not moving a bit or causing a short.

Again, I love the chip, not knocking it. I am simply trying to provide purely facts of what I am experiencing and am open to the idea that there is even something I could be doing wrong.

I will go ahead and record my instances here, and update the OP just for the sake of tracking anything I come across. 

Fuse Trip Instances:

1. First prototype test mod, worked great for about a week and a half and then just stopped, verified blown fuse.

2. Next day after replacing the above fuse, it popped again. I put a new board in the mod and it is has been fine since. The other board had the fuse replaced and it is now in another prototype mod and working fine. I later identified the atty I was using had a failing insulator which gives my atty short idea some weight, but I find it strange it would be popping the fuse.

3. Saturday I delivered two mods to a local shop owner, and employee, lets call them Mod 1 and Mod 2.

Monday the fuse on Mod 1 pops. I replaced the fused, rewired the board, and tried my epoxy idea around the wires. It has been fine since.

4. Tuesday the fuse on Mod 2 pops. Most of the time when a fuse pops it can still connect via USB and power up, detect, etc. This was not the case here, this chip will not detect, and a replacement fuse does nothing. It is completely dead.

5. I had a mod of the same color finished and gave that back to the customer to replace Mod 2. Today (Thursday) it randomly dies again, and I go pick it up. Again, this board is completely dead with no USB activity, and a replacement fuse does nothing.

6. 8/14 "Mod 1" just blew its second fuse randomly.

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blueridgedog

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Reply with quote  #2 
Just to see if I follow and to toss out some observations:

You are suggesting that there is a level of low resistance that is above that required to give the "atomizer short" error, but that it still could represent a threat to the board?

Having watched these threads and other forums, there appears to be a observable increase in fuse blows in metal enclosures than plastic ones, especially ones that rely on a nut on the inside of the case, pressed against the board (Opus).  One theory is that the nut allows the board to be installed to tight and that the board is crushed to the point where layers may contact.  Another is that the nut creates a potential short path to other components on the board.
DogMods

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Quote:
Originally Posted by blueridgedog
Just to see if I follow and to toss out some observations:

You are suggesting that there is a level of low resistance that is above that required to give the "atomizer short" error, but that it still could represent a threat to the board?

Having watched these threads and other forums, there appears to be a observable increase in fuse blows in metal enclosures than plastic ones, especially ones that rely on a nut on the inside of the case, pressed against the board (Opus).  One theory is that the nut allows the board to be installed to tight and that the board is crushed to the point where layers may contact.  Another is that the nut creates a potential short path to other components on the board.


This is great info, and definitely a possible cause! I was saying that my theory was possibly that while firing, if an atty were to short, the split second short could be possibly popping the fuse. Again, I don't know about the inner workings or if this could even be possible, just a theory based on what I have observed.

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blueridgedog

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Reply with quote  #4 
So, if for an instant, the atomizer shorts, and the full negative DC voltage is passed to the ground, therefore the board, that may risk the fuse.  
Ken Nutter

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@Dog this is just an idea... You could possibly take a marker(dry erase maybe) color your standoffs really well and while the marker is still wet put the chip in place and tighten down and see where the marker to transfers to to try and see how close your clearance is to the fire button solder points...(the Opus issue) remember I haven't tried this in this application but I see no reason why it wouldn't work
DogMods

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Quote:
Originally Posted by Ken Nutter
@Dog this is just an idea... You could possibly take a marker(dry erase maybe) color your standoffs really well and while the marker is still wet put the chip in place and tighten down and see where the marker to transfers to to try and see how close your clearance is to the fire button solder points...(the Opus issue) remember I haven't tried this in this application but I see no reason why it wouldn't work


Hi Ken! Thank you for this idea, I think it would help many others! I actually did mill my layout into a flat plate, and fixture the chip in both directions to examine my mounting. As far as I could tell nothing was shorting anything nearby with my hardware size.

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retird

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Reply with quote  #7 
Don't know if this will be helpful but I took a reference device and without an atty attached I shorted the center pin to the shell of the 510 connector and got the atty shorted error message.  Attached an tank atty and all is well.  No blown fuse.
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DogMods

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Quote:
Originally Posted by dc601
Don't know if this will be helpful but I took a reference device and without an atty attached I shorted the center pin to the shell of the 510 connector and got the atty shorted error message.  Attached an tank atty and all is well.  No blown fuse.


This is massively helpful. I was planning to do this tonight. Did you try it while it the mod was firing? IE laying screwdriver across the atty posts, etc?

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retird

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Reply with quote  #9 
Yes, I shorted the center pin to the 510 shell and pushed the fire button and got the error message. No error message until the fire button was pushed.
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Tomr1088

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Reply with quote  #10 
I'm just goin out on a limb but I've seen a lot of weird issues with mods grounded through the casing. Ones that were installer error obviously. But I don't suppose that while firing the connection problem is causing an atomizer resistance reading far off in that the chip is overpowering and causing an amp draw past the limit while not being aware of it. This could cause the fuse to pop but also possibly the board to fry itself
DogMods

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Quote:
Originally Posted by dc601
Yes, I shorted the center pin to the 510 shell and pushed the fire button and got the error message. No error message until the fire button was pushed.


Sorry, I don't think I was clear enough, I meant to actually create a short while the mod is actively firing. IE, fire the mod, as it is producing vapor THEN short the atty. I am not sure if this would be enough to split second pop the fuse or not.

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turbocad6

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Reply with quote  #12 
I made an aluminum sled to mount my 200 and shorting was a big concern. I inspected everything well and I found a few places where I needed to reduce my standoffs to a really tiny landing just to give good clearance to adjacent stuff. also the screws needed here are really tiny with really tiny heads I winded up finding screws tiny enough in an old cellphone screen mount but before I found the right screws I found some that were almost small enough but not quite. if you use screws that are not tiny enough your increasing your chances of shorting or damaging the board  
blueridgedog

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Reply with quote  #13 
Quote:
Originally Posted by DogMods

Sorry, I don't think I was clear enough, I meant to actually create a short while the mod is actively firing. IE, fire the mod, as it is producing vapor THEN short the atty. I am not sure if this would be enough to split second pop the fuse or not.


That is the step I am curious about as well.  Any metal case where the chassis is the ground, to fire the mod normally then short it while mid fire.  If that is ruled out, then we are only left with mounting methods, fastener size as it relates to adjacent chips or components and the amount of torque placed on the fastener.

These are the only issues where non-conductive enclosures and conductive ones vary.
DogMods

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Reply with quote  #14 
Updating the OP, "Mod 1" just blew its second fuse.
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DogMods

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Reply with quote  #15 
Repairing "Mod 1" now and am going to put Kapton around each standoff and see if that resolves the issue.
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