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Electronics => Electronics => Topic started by: Sherlock-holmes2 on October 02, 2012, 01:43:59 PM

Title: Axon 2 problems
Post by: Sherlock-holmes2 on October 02, 2012, 01:43:59 PM
I was putting my Axon 2 on my computer (Because it's grounded, right?), without insulation, and my father told me that I was shorting it by doing so. From then on I put it on my static proof bag to program it (AVRISP MKII), but it doesn't turn on the marquee when I turn it on. Is it fried? If not, what is it and how can I fix it? Please Help!
P.S. For future reference, does the Axon 2 carry a warranty? If so, it would give me a sense of security.
Title: Re: Axon 2 problems
Post by: newInRobotics on October 03, 2012, 04:19:21 AM
I was putting my Axon 2 on my computer (Because it's grounded, right?), [...]
Computer case should be grounded but not necessarily it is.

[...] and my father told me that I was shorting it by doing so.
It's not that You shorting it, but rather electrostatic charge is acting upon it, which might cause damage.

From then on I put it on my static proof bag to program it (AVRISP MKII), [...]
When Axon is connected to programmer, it gets grounded via USB and computer PSU, so electrostatic charge does not accumulate. Electrostatic bag is used for storage only. I must add, that in my life I have resembled many computers without wearing grounding strap and never I had any issues with parts not working after handling them, from this I make assumption that circuit boards are not that sensitive. I might be wrong though.

but it doesn't turn on the marquee when I turn it on. Is it fried? If not, what is it and how can I fix it?
Did it work before, or was it the first time You tried powering it on? Did You power it from external power supply, or via programmer? Does Your programmer have any indication lights light indicating that it works properly?
Title: Re: Axon 2 problems
Post by: Soeren on October 04, 2012, 05:33:47 PM
Hi,

[...] I must add, that in my life I have resembled many computers without wearing grounding strap and never I had any issues with parts not working after handling them, from this I make assumption that circuit boards are not that sensitive. I might be wrong though.
Bad boy, go to your room (oh, you're there already)  :P

Please review your assumption on the subject of ESD.
In most instances ESD will not show instantly and it may show up much later - months or years, as ESD will typically deteriorate some junctions to a point where they are not totally burned, but fairly weakened  - like eg. a semiconductor trace that is reduced to say 20% of what it should be, so next time it's working hard, it may blow or it may take a number of sessions before it gives up.

Problem is that you cannot see ESD, so it's prudent to do as much as you can to avoid it.
The higher the impedance, the greater the risk, but even a 2N3055 can suffer.
Title: Re: Axon 2 problems
Post by: Gertlex on October 04, 2012, 11:57:10 PM
Hi,

[...] I must add, that in my life I have resembled many computers without wearing grounding strap and never I had any issues with parts not working after handling them, from this I make assumption that circuit boards are not that sensitive. I might be wrong though.
Bad boy, go to your room (oh, you're there already)  :P

Please review your assumption on the subject of ESD.
In most instances ESD will not show instantly and it may show up much later - months or years, as ESD will typically deteriorate some junctions to a point where they are not totally burned, but fairly weakened  - like eg. a semiconductor trace that is reduced to say 20% of what it should be, so next time it's working hard, it may blow or it may take a number of sessions before it gives up.

Problem is that you cannot see ESD, so it's prudent to do as much as you can to avoid it.
The higher the impedance, the greater the risk, but even a 2N3055 can suffer.

I absolutely believe you, but for what it's worth, my electronics course in undergrad mentioned nothing of non-instant damage. Perhaps it's OK that I've forgotten all the details of that class...
Title: Re: Axon 2 problems
Post by: Admin on October 17, 2012, 09:03:37 PM
I was putting my Axon 2 on my computer (Because it's grounded, right?), without insulation, and my father told me that I was shorting it by doing so. From then on I put it on my static proof bag to program it (AVRISP MKII), but it doesn't turn on the marquee when I turn it on. Is it fried? If not, what is it and how can I fix it? Please Help!
P.S. For future reference, does the Axon 2 carry a warranty? If so, it would give me a sense of security.

The marquee will only turn on if you program it to turn on. Does your program use the marquee?

I can't offer a warranty because of the high probability a beginner will make a silly mistake. But what I do offer is personal support to help you repair your Axon (or at least work around the problem) if you have one of those 'moments' :P
Title: Re: Axon 2 problems
Post by: briselec on January 04, 2013, 03:06:01 PM
The marquee will only turn on if you program it to turn on. Does your program use the marquee?

Really? Mine came on when I first turned the board on, before I had written a single line of code.

I believe the OP's father meant that putting the board on the computer case may cause a short between the solder joints on the back of the board. I would point out that antistatic bags are slightly conductive( that's how they do their job) whereas computer cases are painted so moving the board from the computer case to the antistatic bag was actually going from bad to worse.
Title: Re: Axon 2 problems
Post by: Admin on January 04, 2013, 03:20:59 PM
The marquee will only turn on if you program it to turn on. Does your program use the marquee?

Really? Mine came on when I first turned the board on, before I had written a single line of code.
Yeap, that's the test program running. I assumed Sherlock-holmes2 overwrote it.

Quote
I believe the OP's father meant that putting the board on the computer case may cause a short between the solder joints on the back of the board. I would point out that antistatic bags are slightly conductive( that's how they do their job) whereas computer cases are painted so moving the board from the computer case to the antistatic bag was actually going from bad to worse.
Although true, I often use my mcu's on anti-static bags without a problem. I like to program my bots while stretched out on the carpeted floor with a pillow, so gotta put it on something :P
Title: Re: Axon 2 problems
Post by: jwatte on January 04, 2013, 06:57:43 PM
Quote
my electronics course in undergrad mentioned nothing of non-instant damage

You probably weren't working with CMOS circuits and MOSFET transistors. The old-school BJT transistors and TTL circuits are much less susceptible to ESD damage.