Topic: Bfl jalapeno failures and USB problems, SOLUTION FOUND (Read 5457 times)

There is a fair bit of extra pad, might fit. Worth a try...

How about the HF? The things cost 5 bucks here in the US. What's with the high euro price?

C

I think the problem is the power supplies have a capacitor going from one of the two AC pins to the DC neutral. This can be very helpful for increasing the power factor, but if the capacitor were to short then it would conduct one of the 240 volt legs to the negative line on the jally.

This 120 volts would not be a problem except for the fact that it goes to the ground of the USB line. Which then goes to your computer. If your computer's USB jacket is grounded, then 120 volts goes from wall through broken capacitor through jally through USB cable to computer to frame ground back to the utility. Boom.

Speaking of which, one should be able to replace this chip with an LQFP 48 pin one which would be a hell of a lot easier to solder. Recommended for followup.

C

Thank you very much for your report, lightfoot.
The same thing has happened to my friend's Jala. Power adapter failure, and the unit not recognized thereafter. Booting normally, LED flashing first, than steady, two LEDs for two chips... So I believe the PSU has taken the USB chip with it, as you have found and verified.
It's not quite simple to obtain a new one though. There are several types & packages of FT232, but the HQ one is not frequent at all...
Mouser wants 40 euros (!) for p&p (or I've failed to find a better offer), maybe Farnell will be more acceptable, its shipping is "only" 150% of the price of the component itself... :-))) I've left this on the owner of the cube. I myself don't have one unfortunately...

BTW, what's Miller? A sort of beer, I guess? ;-)

After a quick read thorough, my 2 cents worth.

Am sure alot of these units will have been pluged in using a US/Euro adapter.

The PSU I received is auto switching so voltage is not a problem.

I have seen many of these adapters that do NOT carry an earth/ground pin. In this case the PSU may technically fail safe but the adapter is preventing the fault path to achieve this, raising the potential between the chasis ( and USB GND) to the ground. OUCH. So the fault path becomes dependent on the USB connection to the PC, be careful plugging that baby in 

Easy solution, cut the plug off and put a local one on, seek advice on connections

Brown = Live/Active
Blue = Neutral
Green/Yellow = Earth/Ground

or

red 2 red , black 2 black and blue to bits   

Ok, I've thought about this and the chip would sit at a completely different height look at your chips and the ones BFL put on. You can see with a flashlight and bare eye underneath. Theres a small amount of space created by the solder balls. If they say perfectly flat with solder those little balls would cover a lot more area. W/o the balls it will prolly cause heat issues from 2 things the heat not being dissipated into the sink right unless you shim, and the bad contacts on the BGA can cause numerous problems like the connection occasionally bridging or burning out. I don't even know what size balls these are or if they make a template for the masses to easily reball with enough time a template may not be needed.

As for the dead jallie I think you're right about it being a short. I don't know the places to look, I've literally stared at it for ever. It's a second rev board with only one JTAG so it may not lay it out as simple. I'm not following traces on the back of the board though. If I got a nice pic and started labeling board parts would you want to fill in where you can?   

Yes I floated the chip off like putting the ASIC on. Pre the area with some flux and heat again to flow smooth. Put new chip on, flow it onto the board. while its still hot put a little more flux and solder the leads on good. Clean up as necessary. (A short wouldn't make ya happy right?)

I think this was the hardest chip to put on yet. My forth jallie when given enough power by a 1500 Watt PSU lit the power LED for a sec and is now dead again. Hmm back to square one with out a hole in the chip this time. I want to know if anyone successfully reballed a chip yet. I don't have a problem with stealing the chips then.

Update: Took the old 232 chip off the board. You cannot do this with a soldering iron, the back of the chip is soldered to the board via a ground plane. Think air tools and temps of 450c+ for over a minute. That's a massive amount of heat.

C

I'm trying to do what you're doing as well by adding more chips to the device ( eventually 6 ).  I made my own adapters using 16 gauge wire, is there any reason you'd think that I wouldnt be able to power 4 chips per device?

The ATX power supply is 1200 watts, and the cables are 16 gauge.  I will admit to have blowing a few breakers as well, but I cant see any reason it wouldnt be able to support 6 per device on a 16G cable.

Generally, a device should either be safety earthed o the chassis can't be energized, or be double insulated. In this case, it would be a double insulated device. They are designed so that no single fault can cause the mains voltage to be exposed. A good power supply should not fail this way even if it does die, it should just stop working. There is obviously something very wrong with these ones as they appear to be able to provide significant mains current at the output, and still function otherwise normally. It will be interesting to see what you find, do you have much experience with mains powered SMPS designs?

Hopefully (and some bitcoin later) I will be having one come in here for review. I think it is fail-destructive, which is not good. But I think any power supply could do this, the problem is the ground loop back to the computer which is grounded equals the usual boom.

C

I don't have one of the failed ones here, but I'm not so sure they're failing in a safe way. A power supply that fails in such a way that gets a strong shock through their arm by touching it is extremely dangerous.  BFL needs to stop shipping those supplies, the reports of Jalapenos tripping home circuit breakers is disturbingly numerous.

So the PSU had a fault.  ANY PSU can have a fault.  I've had brand new, out-of-the-box Apple laptop chargers that have died, same with Dell, and HP. 

But, my sentiment still stands, just because there's mains potential between the output ground and mains ground, doesn't mean there's a fault, or that there is a danger.

I had 2 Jallys arrive about 3 weeks ago. Last week one of them tripped the surge protector they were plugged in to. I reset the protector switch and as I plugged the second Jally back in, it tripped again. I suspected a failed power supply, so I disconnected the unit and took it to a friends house ( a licensed electrician,) to look it over.

When we plugged it in at his house, the unit ran fine. I didn't plug it into a computer at this point, nor did I have the USB cable plugged in. I took it home, plugged it in and ran it in the same state on the power board and it didn't trip. The unit booted normally so I plugged the USB cable into the rear of the Jally and picked up the other end to plug it into the computer and received a pretty solid DC shock from the metal end of the USB cable. I unplugged the Jally immediately, it did not feel to me like a little buzz from a faulty USB, the thing kicked like my car battery and it gave me pretty heavy muscle contractions up through my hand, arm and shoulder so I guessed I had the entire DC output of the power supply across the USB cable. I tested a different USB cable it it was live too.

I thought then I'd nailed the problem down, but the unit which seemed to be effected was the one with the better hashrate of the two, so I swapped the units over to be sure. The 1st Jally, the one that had been hashing away while I'd been testing the other faster one, connected to the 2nd Jally's power supply now had a hot USB plug. So somehow, the power supply is the source of the problem, but I can't for the life of me figure out how that works.

I've just read the Troubleshooting your Jally or SC post, but there's nothing in it that sounds anything like this. I did notice the part about posting screenshots with your request for an RMA, which presents a bit of a problem because I'm not about to knowingly jack 13v at 6 Amps into a USB port on the back of my computer. The weird thing is, both Jallys ran fine for a couple of weeks before one power supply went postal and started doing this.

Anyone else?

So the PSU had a fault.  ANY PSU can have a fault.  I've had brand new, out-of-the-box Apple laptop chargers that have died, same with Dell, and HP. 

But, my sentiment still stands, just because there's mains potential between the output ground and mains ground, doesn't mean there's a fault, or that there is a danger.

If you read the thread that photo came from, this is exactly what happened. The PSU killed the circuit and it needed to be reset to bring all the various household appliances and things online. The problem was traced to the PSU. This measurement was taken when the PSU was powered on, plugged up to the Jalapeno but not to the host PC. Connecting it to the host PC caused the circuit to trip, and with a potential like that between the ground, I can see why!

It's not the problem you think it is.  There might well be 120V there, but there's probably insignificant current.  If there were, the RCD or RCBO in the house's electrical system would trip.  

I have at least one EU person who is seeing 120 volts on the ring of his jally power supply to ground. Either his picture is lying, or 120 volts is on the ground plane.

No, because you're making a mountain out of an ant hill.  Please stop spreading FUD.

Does anyone care by the way?

You don't need to do any of that crap.  Just swap the supplied Whooflugdung PSU with something better, be it LiteOn or whatever, or run it off an ATX PSU like I do.