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View Full Version : Petit Crouton/Prizm Fried?



forsytjr
12-22-2014, 07:46 PM
I recently got a Prizm sound card and got it all wired up. I had a tri-color rebel, hooked up as well as an accent light on a switch. No charging port (yet). Everything was working beautifully - sound and LEDs. I was still working on getting it mounted into the saber, when I accidentally put the battery in backwards (negative to positive) - a single 18650. Before I noticed the mistake, some smoke came out from around where the battery wires mount to the board. :( I pulled the battery out, but I can no longer get the board to do anything. I did notice that one of the accent light wires had come detached. So it's possible I shorted an accent LED pad, although it's also possible this happened as I frantically jerked out the battery. In any case, the smoke was from around the battery connection. Looking at the board under a magnifying glass, I can't see any evidence of damage, other than some burn marks on the back side of the surface mounted thing next to the spot where the battery connects to the board. That could be from soldering though. I am suspecting the surface mount device next to the battery terminals has gone bad. The numbering on the top of it is "107 16k 323". After a lot of searching I can't find out details on this device though. It looks like it is some sort of diode/power switch. Any ideas what this thing is, and how to test to see if has gone bad. The resistance across the device is only 20 ohms.

Any ideas would be greatly appreciated before I send it back to Plecter labs for repair. It was supposed to be a Christmas present. :(

Jim

Forgetful Jedi Knight
12-22-2014, 07:51 PM
Welcome to the Forums.

You can PM Zook, who handles repairs here in the United States. Of course there will be a charge to repair/replace the component(s), that you might have accidentally fried, plus shipping costs.

forsytjr
12-22-2014, 09:05 PM
Thanks, I'll give that a shot. I tried PM'ing, and it said I didn't have permissions for that page. Perhaps that is because I just registered my account here today. Lurking for a while, but first post.

Forgetful Jedi Knight
12-22-2014, 09:17 PM
Thanks, I'll give that a shot. I tried PM'ing, and it said I didn't have permissions for that page. Perhaps that is because I just registered my account here today. Lurking for a while, but first post.

That's probably why. If I run into Zook, I'll let him know to pop into the thread.

Zook
12-22-2014, 09:36 PM
Yeah if the voltage is reversed it will blow the main cap and possibly the audio amp. I am out of pocket for a day or two. We can work on getting it repaired after Christmas.

forsytjr
12-23-2014, 05:16 AM
Yeah if the voltage is reversed it will blow the main cap and possibly the audio amp. I am out of pocket for a day or two. We can work on getting it repaired after Christmas.
Thanks!

Obi1
12-23-2014, 12:04 PM
I totally symphatise with you, I did the same mistake with a Hasbro FX board the other day. The reverse polarity killed the Audio amp (well, actually a transistor drive in the newer Hasbros), interestingly everything else remained intact, it still scrolls.

No offense meant, but I really thought, that a PC - which is far from being cheap - has a reverse polarity protection. After all, reverse polarity can happen even with experience users, if they are in a hurry/just tired or whatever. If the battery connections are not protected, this has to be officially requested as improvement. IMHO.

forsytjr
12-23-2014, 01:11 PM
I totally symphatise with you, I did the same mistake with a Hasbro FX board the other day. The reverse polarity killed the Audio amp (well, actually a transistor drive in the newer Hasbros), interestingly everything else remained intact, it still scrolls.

No offense meant, but I really thought, that a PC - which is far from being cheap - has a reverse polarity protection. After all, reverse polarity can happen even with experience users, if they are in a hurry/just tired or whatever. If the battery connections are not protected, this has to be officially requested as improvement. IMHO.

I would have thought it would be protected. Unfortunately, although I have a protected 18650, I wasn't using it since it didn't fit well in the battery holder. After all this, I'm going to put a charging port in so I don't have to touch the battery again, and cram the protected battery in.

Obi1
12-24-2014, 02:08 PM
I'm afraid a protected battery will not protect the board itself from reverse polarity. I'm also not fully sure how reverse polarity protection works, I guess it would be a diode clamp. Anyway, as any serious FMEA would conclude reverse polarity to be the most common fatal wiring error, I really think it should be included, at least from PC onwards.

Forgetful Jedi Knight
12-24-2014, 02:11 PM
With Saber building, as with ANY electronics, there is a degree of carefulness involved, if everything was "fool proof" we would only be selling prewired things that could only do certain things. With options comes responsibilities - being "careful" is one of them. ;)

Jay-gon Jinn
12-24-2014, 08:42 PM
I totally symphatise with you, I did the same mistake with a Hasbro FX board the other day. The reverse polarity killed the Audio amp (well, actually a transistor drive in the newer Hasbros), interestingly everything else remained intact, it still scrolls.

No offense meant, but I really thought, that a PC - which is far from being cheap - has a reverse polarity protection. After all, reverse polarity can happen even with experience users, if they are in a hurry/just tired or whatever. If the battery connections are not protected, this has to be officially requested as improvement. IMHO.He didn't say he had a PC, he has a Prizm...different boards, one of which, the PC, has a voltage regulator...the other one, the Prizm does not. It's been awhile since the development days, but if memory serves, Erv does indeed have reverse polarity protection on the PC and CF boards. Maybe if we're lucky Erv or Zook will chime in and confirm or refute me. ;)

forsytjr
12-26-2014, 10:45 AM
Yes it was a prism, which is based on the PC but works off a single cell li-ion battery.
BTW I wasn't counting off reverse power protection, I was being careful, just messed up. The battery holder I bought from TCSS is completely symmetric with the + and - stamped in the black plastic and it's really hard to see. So I got a light out to check it first, but must have just misremembered which side was which when I put the battery in.

Does a protected 18650 limit the current which could have helped? Or just shut down the battery if it gets too hot, which wouldn't have helped. Can't a diode protect a circuit like this?

I'm not complaining at all about the design. It was totally my fault.

He didn't say he had a PC, he has a Prizm...different boards, one of which, the PC, has a voltage regulator...the other one, the Prizm does not. It's been awhile since the development days, but if memory serves, Erv does indeed have reverse polarity protection on the PC and CF boards. Maybe if we're lucky Erv or Zook will chime in and confirm or refute me. ;)

Forgetful Jedi Knight
12-26-2014, 10:57 AM
No, a protected 18650 doesn't really limit the current. You would need the current to drive your LEDs.

Obi1
01-08-2015, 07:57 AM
With Saber building, as with ANY electronics, there is a degree of carefulness involved, if everything was "fool proof" we would only be selling prewired things that could only do certain things. With options comes responsibilities - being "careful" is one of them. ;)

I know this is more a philosophical discussion, but I like to debate such things for a change... While I agree generally to this statement, certainly the term ANY is misplaced. Electronic industry definitely aims more and more for "fool proof" and safety, and not only in the "high" segments (aerospace, medical, automotive), but also in the field of consumer electronics.
At the end of the day mostly the application decides about the level of "fool proofness".
As for electronics for saber, definitely it's a small and special nichee, but I can see here 2 application segments:
1. electronics for pre-made replicas and toys: I mean mainly Hasbro, but also smaller companies manufacturing full sabers. For these electronics, making it un-proof can even be a design target, because tampering with the electronics void the warranty. There, if someone wants to make modification, he or she must be careful and be aware of the consequences.
2. full DIY electronics, now here per definition the users deal with "naked" boards, exposed to whatever the environment throws at it (ESD, electrical overstress, you name it). For such electronics in the industry the highest risks are correlated to their probability of occurence and safety/protection features are dimensioned accordingly. Without using complicated tools, it's quiet easy to see that in terms of damaging potential and probability, reverse polarity is by far the Numero Uno of all evils. In this sense, it would be good practice to protect the board from that.

Only my opinion, no offence meant!

forsytjr
01-11-2015, 11:42 AM
Yeah if the voltage is reversed it will blow the main cap and possibly the audio amp. I am out of pocket for a day or two. We can work on getting it repaired after Christmas.
Zook, I still can't pm you for some reason. Let me know when you would be able to help with this.

Forgetful Jedi Knight
01-11-2015, 11:44 AM
Zook, I still can't pm you for some reason. Let me know when you would be able to help with this.

I believe that you need to have at least 10 posts to PM.

forsytjr
01-11-2015, 12:08 PM
I believe that you need to have at least 10 posts to PM.

That would make sense since I was at 8. 10 now. ;)

forsytjr
02-19-2015, 10:05 AM
Just wanted to post to say that Zook did a fantastic job fixing my board at an affordable price and quick turnaround time. I highly recommend his services!

Forgetful Jedi Knight
02-19-2015, 10:27 AM
Glad to hear that this is resolved.


Thread locked - FJK