Ah, the days of 390. Life was so simple then....

I don't think it's ever going to stop going up by 20% a shot.

To be honest, Mr. Teal did all this and more with the Chili design. That is without a doubt an amazing board, the BFL singles really aren't built for this kind of stuff.

Which is the whole point why BFL was late: Their chips used more power than they were expecting, forcing a complete redesign. Remember that the initial jalapeno design was to not use the big on-board 1 volt supply, but to use a little supply that was left on the board. It was all supposed to be powered from the USB port or somesuch. That... didn't... work... :-) Likewise the board simply wasn't built to handle the extra 30 or so amps the chips needed for a full 30gh single. They could have made 24 without blowing up the moon but that was it, we all "paid" for 30, and we had to wait months for it.

I wonder how many people would have been happy with 24gh in march as opposed to 30gh in October. But they would have all bitched about being "ripped off", so in the end they came out worse and BFL did the "right" thing. Interesting how that happens...

Anyway, at this point the next system to look at will be the monarch class systems. I could open a repair center for jallies and singles, but would the cost of doing it (let's say $100 an hour) be worth it? Perhaps it would, thoughts?

C

Cool. In that case I will take apart the power supply with my bench vise. They're pretty easy to crack open, I'm curious to see if it will match the UK blown up one (which had dents in the caps from manufacture, *wow*)

C

On another side note I finished reviewing a blown board that was given to me which had a complete blow-out of the 1 volt FETs due to a short.

Micro-summary: It's destroyed. Not because of the FETs; I got those off easily and cleared the shorted 1 volt lines. It's the fact that the whole 3.3 volt line is shorted as well; I was trying to figure out where that went bad and found out there was a nice bubble in the board by the chips. Apparently the 1 volt line not only shorted but it burned inside the board, shorting the 3 volt supply to ground.

Not good :-) So if you blow the FETs, repairs would require board-level digging, not something I would do for a $200 part. I may fiddle with it some more, but for the moment I will classify this as "toast". :-)

C

They are total crap. Crap crap crap. Good for nothing but cutting the power cords off for connection to real power supplies.

I'll check on the BFL forums. Still do not have my PCIe power cable whips.....

C

And in the really interesting news, I had a unit come in with a power supply that went *bad*. Jalapeno, ran it with 3 chips, checked in and saw that it had a massive amount of errors going on. Shut it down, put it on the bench supply, worked fine. Tested the power supply and I see 60 volts between negative and AC neutral.

Glad I have an isolated power supply on my miner. I'm wondering: Does BFL want the old power supply back when they RMA, or will they just send a new one out? I would really like to "interrogate" this one and see if it has the same blown caps as the one from England.

Good news: No damage to the jalapeno. In fact it's now hashing at 14gh with a second added (client provided) chip, much better than the 5.4 it came in with (it has two lousy chips on it and two very good ones).

C

Interesting. I had another unit in here, little single, with a complete load of everything but the hashing chips on the other side. Even had the 1 volt power regulators, no problems adding chips if we wanted too. I guess BFL made some units with half a load, and some with a full set of supporting chips.

C

Are you sure all the pins are soldered and there are no bridges? It took me the ass end of ever to get the FTDI chip working on a jally; class one pain in the ass.

C

Will do! I'm looking forward to it; one question to start with is do the singles contain the supporting hardware to add chips. If they do it's a matter of adding a heatsink (of which I have... several :-) and chips to boost performance.

Should be interesting.

C

You have a good point here: The mining bug is really seductive.

I started mining with a 5gh Jalapeno on 1-September, mined a bitcoin, then started tweaking it and such to get to bitcoin 2. After that the price of bitcoin exploded, and I started really fiddling.

How I have been slaking this thirst is by only buying new miners with Bitcoin, and trying to only buy things that will give a positive return from mining.thegenesisblock.com. The big thing has been BFL chips; I can get a 100% return on investment by buying them for .05btc, installing them, and I will get .1btc back per chip.

And I bought a pair of jalapenos from BFL for $400, then promptly upgraded them to 28gh units with extra chips. They will easily ROI, even at current levels.

It's resulting in my mining area looking like a web of wires, but it is keeping me interested in mining. But man I have serious temptations to buy stuff on Ebay. Just got to keep reminding myself that the right way to do it is to use one's brains and not just toss money into the hole.

C

Currently hashing 160gh with two 28gh jallies, two 20gh jallies, two 16gh jallies, a 35gh chili, and a block erupter. Fun stuff.

I would agree. 12 volts can start fires quite easily if the amperage is high enough (try shorting a car battery with a coat hanger. Wait, don't). Given that some of us are using 1,000+ watt supplies they can feed plenty of current into a dead short, enough to start fires and fun stuff.

Speaking of which, something I noticed in the BFL Jalapeno community: The crap power supplies they send with these things typically put out 12 volts at 7 amps. Nice, and when there is a short on the board the supply crowbars because the components can take 12 volts at 10 amps.

However when someone wires into a big-assed 600 watt power supply, a short will produce 600/12=50 amps of current into the short. Exceeding the capacity of the components, leading to small explosions as the FETs blow up.

This is why I recommend putting a fuse in line with any component rated to the max current the component can take. Yes it costs a buck for a fuse holder and a nickel for the fuse, but it could save your gear. Note: Although this is not really a problem for 12 volt systems plugging into walls, if you are hooking up to a big battery array make sure your fuse can clear the maximum Amp capacity of your pack (Amp-Interrupt-Rating)

Learned this lesson working on electric car controllers, where a 2 amp rated circuit would be exposed to 10,000 amps of current from a battery pack. Hilarity ensues when you have a plasma ball on your bench....

C

The big question of course is when will this "broken miner" be listed on Ebay.

Someone will pay a lot of money for it.

MILFCoin. Gets you.... well, you know what.

C

Honestly, these fakecoins are great for pumping and dumping. It's as old as the hills, and an (il)legitimate way to make a quick buck.

No biggie.

To be honest, it's probably not worth a flash, however there is a guy who can do it remotely if you have the programmer. You have replaced the POS power supply with a locally compiant one, right?

C

Improved is a funny concept. Catcoin is an example how changing the block difficulty calcs has really "improved" the coin for pump and dump miners. So what is the definition of "improve" and for whom?

That's the rub.

Interesting. Can you go back to cgminer and see if the speed goes back? I'm wondering about that a little bit.

C

Speaking of which, I have two jalapenos running at 28gh now with more chips. Both need extra cooling; you can take a stock cooling system up to five chips without anything, six chips with small copper heat sinks on the FETs, and seven chips requires either water cooling or a big heat pipe.

I wonder about 8 chips :-)

C

Sure. In BFGMiner press "D" for disply, then "M" to show all cores. You will see either two or three.

8gh is darn good for a 2 chip jally, I would not try to flash it.

Chris

Hee hee he... It's amazing how much use I am getting out of this dopey little pre-heater. Using it on big boards is much harder, but on the little single boards it does shine. And when I reflowed the chip the result was perfect (and now it's at a solid 60c, I think the heat sink was being lifted off other chips due to the high chip)

I thought about buying an IR station, but then I realized that the trick to using air is to lower the blow speed down so much it's almost like a little cushion of hot air over the end of the heating element. Then the air stays at the right temperature, doesn't go everywhere blowing things off the board, and acts more like what you see with IR. Using the thing as a blowtorch is not the idea.

Live and learn. Now I want to get a Monarch to take apart, but $2,000 is a bit rich for my taste. :-)

C