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Old Mar 12, 2014, 05:52 AM
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Originally Posted by Snowflake6515 View Post
The problem with the FUIM3 interface isn't with the adapter, but that the signal leads in the back of the DPL8 halves, apparently, go directly into their respective microcontroller. Any static electricity on that lead can fry it (that's apparently what happened to my second DPL8.)
Michael
Im a layman, but I believe your failures and mine are somehow related to connecting either the Fuim interface to one channel or connecting both channels with a servo wire.
You mentioned static, that is a random thing and will happen only in some specific conditions. It would explain why many users are plenty happy with their DPL and only a few are having problems.
If this is the root cause, can I do something to avoid running into this problem again? I live in extremely dry weather, what favors static electricity to be created.
Im only using pl8v2 for now and I wonder if I could somehow ground the Fuim cable so that Id never have my circuit fried in any circumstances.
Thanks.
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Old Mar 12, 2014, 08:14 AM
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Quote:
Originally Posted by Snowflake6515 View Post
The problem with the FUIM3 interface isn't with the adapter, but that the signal leads in the back of the DPL8 halves, apparently, go directly into their respective microcontroller. Any static electricity on that lead can fry it (that's apparently what happened to my second DPL8.) I had plugged in the wires while the DPL8 was unpowered. The switch for expansion mode was recycled and the pins crimped elsewhere, installed, with power off, etc.; so no voltages present, no soldering, but plugging in unpowered cables ("Y").

The problem, apparently, was the couple of feet of unterminated cable that could pick upsomething; I haven't a clue where as the unit was sitting on my test bench.

Michael
What this confirmed by FMA to be the root cause of the problem? I don't see an update from Howard.

Howard's earlier post indicated the 12V buck controller was damaged. Seems to me if there was static on one of the microcontroller pins it would have fried the microcontroller or perhaps just that I/O pin on the microcontroller.
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Old Mar 12, 2014, 08:27 AM
Michael
United States, ME, Wells
Joined May 2008
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Two Failure Modes

You are correct. The first DPL8 failure was the 12v buck controller; I still have no idea what caused that or if it might happen, again.
The second DPL8 failure was the microcontroller and Howard explained that the signal pin of the USB connection goes directly to the microcontroller. Howard postulated that static electricity could have been the cause. As I had only plugged the wires in with power off, but there were long leads to allow access from outside the charging case, that could be the problem. I removed them.

I still worry about the first failure mode and am hoping that it is related to the USB/expansion cabling, somehow.

My first unit was repaired and should arrive tomorrow, Thursday, weather permitting. Howard explained that it was restored to factory defaults. That means that I will have to go in with the CSC/USB and change things back to my preferered presets. I wonder if this is what playing "Russian Roulette" is like (tongue planted firmly in cheek.)

I will post my findings, but I am confident (hopeful???) that my simplified cabling and PS 'scope tests should result in success. I will connect the FUIM3/USB interface while outside the case, short lengths, precautions taken to control static electricity, etc.

Michael
Quote:
Originally Posted by Ohmic View Post
What this confirmed by FMA to be the root cause of the problem? I don't see an update from Howard.

Howard's earlier posed indicated the 12V buck controller was damaged. Seems to me if there was static on one of the microcontroller pins it would have fried the microcontroller or perhaps just that I/O pin on the microcontroller.
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Old Mar 12, 2014, 09:01 AM
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Thanks for clarifying. I'm guilty of not always backing up my presets myself, but always a good idea to do so they can be easily moved to another charger or in the case of the DPL8 the other channel.
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Old Mar 12, 2014, 10:22 AM
BVH
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I would hate to think that a static charge caused any of this as static electricity is a daily fact of all of our lives. Why haven't any PL8's or PL6's been a victim of this same issue if static is the root cause?
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Old Mar 12, 2014, 10:42 AM
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Originally Posted by BVH View Post
I would hate to think that a static charge caused any of this as static electricity is a daily fact of all of our lives. Why haven't any PL8's or PL6's been a victim of this same issue if static is the root cause?
Dpl may have a fragility that pl8 and pl6 dont.
If static is actually the cause, can we adopt precautionary measures?
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Old Mar 12, 2014, 11:55 AM
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Originally Posted by Ohmic View Post
Thanks for clarifying. I'm guilty of not always backing up my presets myself, but always a good idea to do so they can be easily moved to another charger or in the case of the DPL8 the other channel.
My process is to get one channel setup how I like it. Then back up all the presets to a file. Finally restore the back to the second channel. Easier than manually changing all the presets on the second channel and you end up with a backup in the process.
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Old Mar 12, 2014, 12:04 PM
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Originally Posted by Can'tFly View Post
If static is actually the cause, can we adopt precautionary measures?
The static concern in this case is on the signal line. Issues can arise if the signal lead is subject to static. This can happen if the user constructed harness leaves signal line electrically exposed. I'm not saying this what happened, but if walk across a carpet and touch the signal wire its likely going to damage the uC.

Use standard static practices such as regularly touching a ground while working on equipment or using an antistatic wrist strap. While building the jumper, it should not be connected from the charger. The signal wire should not be left exposed. The wires should be kept as short as possible for the application.
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Old Mar 12, 2014, 12:17 PM
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My process is to get one channel setup how I like it. Then back up all the presets to a file. Finally restore the back to the second channel. Easier than manually changing all the presets on the second channel and you end up with a backup in the process.
Absolutely, no reason to invent the wheel twice. Plus, it's the only way to guarantee the presents are identical between chargers/channels.
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Old Mar 12, 2014, 12:22 PM
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Originally Posted by Gregor99 View Post
I'm not saying this what happened, but if walk across a carpet and touch the signal wire its likely going to damage the uC.

Use standard static practices such as regularly touching a ground while working on equipment or using an antistatic wrist strap. While building the jumper, it should not be connected from the charger. The signal wire should not be left exposed. The wires should be kept as short as possible for the application.
Note the static sensitivity issue is true for any microcontroller.

I would be inclined to increase the length of the USB extensions if necessary.
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Old Mar 12, 2014, 12:24 PM
Michael
United States, ME, Wells
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Yup

Precisely how I've done it for my two PL8s and the DPL8s. So much easier that way, plus available when I need them as when a factory reset takes place (repair process...)

Michael
Quote:
Originally Posted by Gregor99 View Post
My process is to get one channel setup how I like it. Then back up all the presets to a file. Finally restore the back to the second channel. Easier than manually changing all the presets on the second channel and you end up with a backup in the process.
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Old Mar 12, 2014, 12:39 PM
Michael
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Joined May 2008
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Short Wires: Probably Key / Critical Point

I fabricated the switch, incorporated a pair of "Y" extensions, modified female-female servo extension (with switch), etc., and installed all while power was off.

However, because my PS and DPL8 were mounted in a case, with a charging deck (rectangular opening for DPL8), I added long leads to have a neat wiring harness from the two DPL8 servo connectors to a pair of bulkhead connectors (couldn't get Ernst (bulkhead) male servo jacks to work, so used Multiplexto-JR servo adapters.) Then, to use the FUIM3/USB connections, I needed 6" Multiplex adapter to JR male servo plug.

Lots of wire instead of either (1) direct FUIM3 / USB plugged into the back of the DPL8 or (2) a "Y" with female-female servo lead plugged into the other half for Expansion mode.

Regardless, I had a lot of wire with signal leads open. Dressing the wires, I tried to avoid the PS and cooling fans, but space can get tight and I wanted to tie things off, neatly, etc.

I am banking on the open signal leads being the problem, but I did not notice any static discharges; 'course, I wasn't paying attention to that.

I did use the static wrist band-ground strap when installing the dual Schottky diodes in the first version, but not while "using" the DPL8 (including CSC options and preset changes, backup, restore ops...)

Michael
Quote:
Originally Posted by Gregor99 View Post
The static concern in this case is on the signal line. Issues can arise if the signal lead is subject to static. This can happen if the user constructed harness leaves signal line electrically exposed. I'm not saying this what happened, but if walk across a carpet and touch the signal wire its likely going to damage the uC.

Use standard static practices such as regularly touching a ground while working on equipment or using an antistatic wrist strap. While building the jumper, it should not be connected from the charger. The signal wire should not be left exposed. The wires should be kept as short as possible for the application.
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Old Mar 13, 2014, 03:45 PM
Michael
United States, ME, Wells
Joined May 2008
1,127 Posts
Now Working: Third Time's A Charm :-)

I received my repaired DPL8 back, today. I immediately installed it in my case on top of the Meanwell 48v PS (dialed back to 41v, current limit set to 28amps.)

As previously mentioned, I removed all wiring between the USB/Expansion ports, so now it is just the PS, DPL8, and two MPA boards with extension leads passing through the charging deck.

I had no problems connecting the FUIM3 USB interface to the DPL8 halves, separately, and was successful in reloading my saved presets and options. I did use the grounded wrist strap while inserting and removing the FUIM3 device; as indicated in a message from Howard when he postulated that static electricity might have been the problem.

I've switched between internal AC powered PS and external Pb; no problems.

I do recall the old saying that the definition of insanity is repeating the same thing hoping to get a different result; at least that is what was passing through my mind as I made and broke connections.

I want to thank Howard for his patience and troubleshooting skills as well as the quick turnarounds. There had to be a certain amount of trust on both parties: Howard, that I am not a complete moron and did not do something egregious and me, that my confidence in FMA products and service were justified.

Thanks to all who helped out. My personal recommendation is to leave the USB/expansion ports empty and only plug in the FUIM3 interface when needed, to a powered PL8, direct cabling, etc., and use a grounded wrist strap unless absolutely sure no potential exists for static discharge...

Lesson learned; at least I hope it is the right lesson (whistling in the dark...)

Michael
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