For one of m-boards, the cables that connect the PSU with the rPI seem to be getting hotter and hotter over time. In fact, the white connectors are starting to get brownish.  I have not done any over clocking.

Another board with even more h-cards is actually cooler than the one I mentioned before. The PSU supports more power than what the set of m-boards consume.

Does anyone know why this might be happening? Any workarounds? :-/

Did you find a way to get them to work? I am having the same issue.

anyone have a link to the pi image?  or can i just use a standard raspbian image and then copy over the chain miner etc.

Did you ever figure out what was wrong with your H-Card. I own a lot of these cards and I have at least 16 dead H-cards between all my rigs that I'd like to get them up and running. I did once observe one H-Card pop and I saw some smoke and definitely could identify the electrical burn smell. I determine the 30 amp fuse on the board was no longer allowing current to go through so I desoldered it and replaced it with another fuse. Unfortunately that board no longer works and the board looks completely fine. The other 15 or so defective boards between my other units also look good but don't hash.

i dont think i ever hotplugged, but i havent tried putting the bad card back in for months now since its at home and the bitfury is a 40min drive away, for only ~33GH if it worked magically.

there was no visible issue on the board, but i alcohol cleaned some of the dusty and greasy components

Here is how i solved the mboard connection problem:


ill post some more with an actual mboard with these on, self made of course

Edit: daddyfatsax care to sell those unused bitfury boards?

If you had any pics of this setup, I'd be interested in seeing them.

Thanks for the pix, interesting setup. I just purchased a hot air rework station and figured this would be a great project to learn on and possibly salvage some boards. I'm pretty good with a soldering iron so this shouldn't be too bad. I'm looking now for an oscilloscope that looks decent and would be great for this project along with other projects I might tinker with in the future. My parts should arrive next week some time, so the salvaging of the boards begins next weekend.

Hot air station I got
http://www.amazon.com/gp/product/B00A2VQA24/ref=oh_aui_detailpage_o00_s01?ie=UTF8&psc=1

I checked 5 cards tonight in over 20 dead cards in my defective bitfury card stack and I've found that all of them have no voltage going to the bitfury chips. I checked this by using a multimeter and saw 12 volts coming out of the fuse. Then I checked the inductor and used the bottom of the voltage regulator pad as the ground and saw no voltage. So what are the odds that the voltage regulators are all toast? I have no experience with the durability of these voltage regulators and if they were pushed to far maybe they finally just kicked the bucket. I bought an intersil 0-6v 30 amp board below to verify if the chips do in fact work. I should have it in a few days to verify if the bitfury chips are indeed good. If the h-boards traces are gone, and replacement pcb's aren't available, maybe I'll try to design a board with all these chips in series so I don't need to use a vreg which should make it more reliable. If I run them in series of 16 bitfury chips with 12 volts, then they'd only get .75 volts or so which will keep them running efficient and cool. I checked the voltage on a few good H-cards and they are taking .865 volts, and they've been this way since day 1 as I've never adjusted the potentiometer. Anyone know the rest of the h-board pinouts on the pictures I posted.

Power Source
http://www.mouser.com/Search/ProductDetail.aspx?R=ISL8225MEVAL3Zvirtualkey57760000virtualkey968-ISL8225MEVAL3Z

I'll hopefully will have the Intersil 30 amp development board tomorrow. I had a chance to use my new hot air station. I removed the old TI buck converter on the H-Board and replaced it with a new one. Unfortunately I didn't have any voltage before the inductor prior to removal of the old part and also after I installed the new one. I tried another new TI buck converter and had no luck here either. This was the first time I've ever used a hot air rework station, so I decided to just practice on one of my h-boards removing capacitors, resistors, buck converter, and inductor. I got the hang of using the hot air station, so I figured I'd try it on the solid aluminum capacitor. I removed the capacitor and then I started replacing the components that I removed. I reinstalled everything with no issues until I got to the aluminum capacitor. I guess I heated it up to long and it blew up. Lucky it didn't hit me in the eye as at this moment I had placed my saftey glasses on the work bench and forgot to put them back on. I'll have some more time tomorrow to mess around with the boards. I'll post the TI stock h-board buck converter diagram here.