Anyone Else Worried About Their Pandora Getten Stolen

[urjaman]

"Do not touch when live"

It's the feedback loop for the 5V supply and the capacitance from your body is enough to throw it out of whack and even destroy the chip. It's ridiculously sensitive but it runs fine if you leave it alone.

I believe "the chip" means the 5V boost converter chip. I believe that the Pandora has no chip that uses that USB +5V supply (except the boost converter, and maybe if the mA limit (500mA, peak 750 mA) is a seperate device). I would be very worried about the health of any attached USB devices when you touch that thing, though. Not that it would be a nice thing to lose powered USB output...

Btw, I've touched some part in a random +5V SMPS supply and it gave me +7V, so its not a pandora only "problem".

 

[BackAssward]

"Do not touch when live"

It's the feedback loop for the 5V supply and the capacitance from your body is enough to throw it out of whack and even destroy the chip. It's ridiculously sensitive but it runs fine if you leave it alone.

I believe "the chip" means the 5V boost converter chip. I believe that the Pandora has no chip that uses that USB +5V supply (except the boost converter, and maybe if the mA limit (500mA, peak 750 mA) is a seperate device). I would be very worried about the health of any attached USB devices when you touch that thing, though. Not that it would be a nice thing to lose powered USB output...

Btw, I've touched some part in a random +5V SMPS supply and it gave me +7V, so its not a pandora only "problem".

I never said it was a Pandora only problem, just something to remember (and possibly coat in epoxy). Isn't the 5 volt input power supply also using this chip? If that's the case, wouldn't frying this also cause you to be unable to power/charge the device (and we have no external battery charger)? That's a question, I don't know if it is used in powering/charging the Pandora myself.

Edit: I still don't know if conductivity can fry it, but it's safer to assume it can.

 

[urjaman]

Isn't the 5 volt input power supply also using this chip? If that's the case, wouldn't frying this also cause you to be unable to power/charge the device (and we have no external battery charger)? That's a question, I don't know if it is used in powering/charging the Pandora myself.

The TWL4030/TPS65950 has a 100mA "4.8V" charge pump to power the OTG port. The USB and "AC" charging systems are seperate from the host ports power. Or who knows, but thats how the OMAP system is "meant to be designed" - i'm inferring this all from what i remember, having spent some time reading the TPS65950 TRM and the OMAP3530 TRM.

 

[BackAssward]

Isn't the 5 volt input power supply also using this chip? If that's the case, wouldn't frying this also cause you to be unable to power/charge the device (and we have no external battery charger)? That's a question, I don't know if it is used in powering/charging the Pandora myself.

The TWL4030/TPS65950 has a 100mA "4.8V" charge pump to power the OTG port. The USB and "AC" charging systems are seperate from the host ports power. Or who knows, but thats how the OMAP system is "meant to be designed" - i'm inferring this all from what i remember, having spent some time reading the TPS65950 TRM and the OMAP3530 TRM.

I will bow to your expertise, as I am no expert on these matters, I can only interpret from what has been said. So basically, from what you know, we may only fry the outgoing USB power supply (if this chip goes dead). Do you know if a conducting liquid will fry it? How about the other power components for incoming power, are they susceptible to the contact of a human (or possibly a conductor), in that they would fry (not just temporarily short out)?

I hope those questions don't sound flippant or accusatory... I just want to know. Thanks for your posts, a post by a knowledgeable person is invaluable.

 

[urjaman]

Do you know if a conducting liquid will fry it?

I have no idea. I wouldnt want to test, though.

How about the other power components for incoming power, are they susceptible to the contact of a human (or possibly a conductor), in that they would fry (not just temporarily short out)?

If you water your pandora, i'm much more worried about the health of digital IC's throught the board than the charge circuitry. It should have a resistor (0.22ohm IIRC) to measure charge current and some transistor to control the charge current, not many components to fail, and theyre not capable of generating dangerous voltages like a boost-up converter.

 

[BackAssward]

Do you know if a conducting liquid will fry it?

I have no idea. I wouldnt want to test, though.

How about the other power components for incoming power, are they susceptible to the contact of a human (or possibly a conductor), in that they would fry (not just temporarily short out)?

If you water your pandora, i'm much more worried about the health of digital IC's throught the board than the charge circuitry. It should have a resistor (0.22ohm IIRC) to measure charge current and some transistor to control the charge current, not many components to fail, and theyre not capable of generating dangerous voltages like a boost-up converter.

Thanks for an honest reply... I know that was all english, but I guess I have to research some terms to get it all. When you say "it should", I hope it does, MWeston seems very capable, so until we have a board, we should assume it does, I guess (as was your point). I do worry about the power system shorting out irrevocably, but we will see.

Thanks for the informative post.

 

[urjaman]

When you say "it should", I hope it does, MWeston seems very capable, so until we have a board, we should assume it does, I guess (as was your point).

I'm saying just that I dont know anything you couldnt check, and that means that i havent actually seen the pandora schematics.
I trust that MWeston knows this stuff much better than me.
But, for example TPS65950 TRM (swcu050d.pdf available from ti.com, google it if interested) page 512:

Battery charging current (ICHG) is sensed using a 220-mΩ external resistor connected across the VCCS
and the VBATS pads of the device.

 

[BackAssward]

When you say "it should", I hope it does, MWeston seems very capable, so until we have a board, we should assume it does, I guess (as was your point).

I'm saying just that I dont know anything you couldnt check, and that means that i havent actually seen the pandora schematics.
I trust that MWeston knows this stuff much better than me.
But, for example TPS65950 TRM (swcu050d.pdf available from ti.com, google it if interested) page 512:

Battery charging current (ICHG) is sensed using a 220-mΩ external resistor connected across the VCCS
and the VBATS pads of the device.

I was talking about, you clearly have expertise in this matter, and MWeston for sure. So if you say "It should have a resistor (0.22ohm IIRC) to measure charge current and some transistor to control the charge current." Then I will take that as enough to believe it does... that's the "it should" part I was talking about.

Again, thanks for the informative post.

 

[hobbyman II]

I think if it needed potting in epoxy then it would have been done at the factory, just don't touch it if you open the case, seems simple enough.

lots of devices pump up the voltage from their battery pack to get things to work (like screen backlights), including mobile phones, this is prolly just a reference circuit derived set-up just like loads of devices using the same chip, lots of stuff comes with serious sounding warnings, hell, if you ask Intel, they insist you can only handle CPU's/MOBOS with the correct anti-static protection (strap, metal, grounded bench, approved procedure etc) , but it's common for people to upgrade their gear in their spare room with nothing more than common sense for protection.

just cos you should not touch it, doesn't mean anything evil will happen if you do, just that it's best left alone, if MWeston makes a post sometime, then ask him, I'm not worried at all about its robustness, PLUS, how do you know adding epoxy will not impair heat dissipation or leave it prone to static build up or something, and cause it fail a week later?, best not to tamper unless you know exactly what you are doing, hell, even adding the epoxy could kill it for all you know, resin/catalyst could attack lead free solder joints or something)

 

[BackAssward]

Hobbyman, very good points, but I think that MWestons posts indicate no covering by the factory (in that thread). Unless things changed since then. Al thought some sort of covering might have an ill side effect, it is a game of which is worse. I don't know if I will add a covering (as I said I didn't know if I would)... just bringing up the topic so others know of it.

Yeah, I know of the static strap, and when I was a bench tech, I thought it was funny. I did actually kill a board with static once, but the manufacture replaced it, since static damage is hard to determine, so it looked like a failure (warranty replacement).

 

[Exophase]

I had a DS that got stolen by someone who broke into my house :/ They didn't take my PSP or GP2X ;p

 

[VRAndy]

I try to be pragmatic about these things. The cost of buying a new Pandora wouldn't break me, so I try to to spend too much time and effort worrying about it. If I stop enjoying the thing because I'm paranoid about losing or breaking it then 'guaranteed' not to get my money's worth.

I hit upon this philosophy when I realized that stick-on screen protectors were detracting from my enjoyment of my gadgets. So I usually don't bother with them any more.

 

[zevdawg]

Considered waterproofing if you're paranoid of getting the thing wet?

I found the old article on Engadget... they call it 'Golden Shellback'. Not sure if they're still around tho, the source link on Engadget's bringing up an OpenDNS page that says it's not working (their blog's working tho). Also I think I read about such coatings before being done by said company (or maybe it was a different one), costing $100USD. Not sure if that was the same company or not though. And one should do so when the warranty expires, cause they're applying something hard to it (my guess is a clear-coat epoxy resin).

Getting it stolen?
That's what cargo pants are for. They'll never guess which pocket to look in, cause that would take too much time :lol:
Lanyard? Haha. That's for newbs. You want a surgical steel chain-link to go with the pants B)