(sorry for the size of the pictures)

Previous projects:
My Custom Case Build
My Custom Gridseed Case Build

Proud owner of a new A2 Mega Terminator (110 Mh/s). As with all my stuff I bought it just for fun and am not interested in ROI. I have an older A2 Terminator that runs well other than it occasionally turns off on its own. I suspect the power supply.

My new A2 Mega Terminator started right up and would mine as advertised for about 10 minutes and then turn off. The Pi controller would still be running but all the blades would shut down. After speaking to Innosilicon support we discovered that the power supply was the culprit. It would run great with 5 out of the 6 blades attached but with the 6th one it would turn off after about 10 minutes. Most likely due to it drawing more power than it could consistently provide.

This was my first direct experience with Innosilicon and I do have to say they were pleasant and professional to deal with. It can be difficult due to the time and language barrier but they did their best to ensure I was a satisfied customer.

After we determined it was the power supply they sourced a new vendor/model and shipped me a replacement. This took about a week to accomplish and during the wait I decided to use one of the AX1200i power supplies from my old GPU rig since I had just recently (finally) shut it down for good. Is this overkill? Most definitely. I would not go out and purchase one for use in an A2 Mega Terminator but since it was literally laying around with no plans for use and I wanted to start mining I decided to go for it.



If you are familiar with the AX1200i you know it is a rather long power supply but it fit! (barely)

For reference here is a picture of what it looked like with the stock power supply. Note that this power supply has exactly six Eight-Pin +12 V CPU Power Connectors with cable lengths perfectly spaced for the location of the blades. In order to use them with the blades which have standard 6 pin PCIe connectors they had to reverse the direction and FORCE them in to fit!   (the replacement power supply I eventually received from Innosilicon had the appropriate PCIe connectors)




First thing I had to do was carefully bend the housing to accommodate the different power plug location. I suppose I could have cut it off but it was easy enough just to bend it with pliers.




I tried to capture exactly how close the AX1200i fit inside the case. There is about 2-3mm of space. Barely enough to plug in the PCIe cables but it fit!



All done...not sure it looks much better but in the next post I will document how efficient it runs.



To be continued....

Reserved...misc...future plans...plug the built-in monitoring capabilities of the AX1200i (CorsairLink) into the Pi?

I actually replaced the power supplies on two of mine as well, very similarly to yours.  I used the EVGA 1300's, but they're the same size as the AX1200i, so same deal basically.  The power draw at 1200 for the A2 Mega is about 1060w at 110v using the EVGA, so if you use the normal logic of 80% utilization, then 1200w or more would be ideal.  I've got a bunch of A2's, and I've seen probably 3 different power supplies - one with a bitcoin logo on it, one that has "Game" in the name (don't remember the rest), and one that is completely black with no markings.  Some are listed as 1100w, some 1000w, and some 1300w, but to be honest I think the only difference is the silk screening on them, I would put very little faith in them.

The 6-pin PCIe connectors on your blades indicate that it's one of the newer A2 Mega's (like the ones I got from Zoomhash).  The older have an 8-pin PCIe connector - but once again in classic form, some of the power connectors on the stock machines have 6-pin connectors plugged in, so basically not using 2 of the pins, so they must just be bridging all the power together on the board or something similar.

The EVGA works fine with the case, you don't need to bend the corner when screwing it in, which is nice.

On the power breakout on the A2, there appears to be two mounting options - the newer one is like yours, where it mounts to the top (side?) of the case and it's a tight fit with the larger PSU.  With the older units, their power breakout sits on a metal bracket that docks onto the first blade - this actually makes for an even tighter fit and using the power supply even more difficult.

In terms of operation of the unit - mine wouldn't run at 1200Mhz on 110v (worked fine at 240v) with the stock power supply, but it works fine with the EVGA.  So is it worth replacing?  I'll probably replace mine all with PC PSU's as they fail, but if it works, then wouldn't bother.  I will say that the machine runs infinitely happier on 240v than 110v with the stock power supplies, so if it's an option, then definitely do it.

Personally I like the A2's, I think they're a great scrypt miner, although my experience with any other scrypt ones is zero (I primarily do BTC).  If you haven't checked out my custom A2 image, then you definitely should, as it adds some nice features to the unit:

https://bitcointalk.org/index.php?topic=1141802.0

Yup, that's the one - although I made my decision based on the same logic as CartmanSPC, ie I had two of them sitting around and I had just bough two new A2's, so to my mind it was destiny!    I think you're good to go with anything 1200w or greater - I have a bunch of AX1200i's and I love them - NewEgg was selling some refurb'd ones on eBay last week for $180 and I picked up 3 more, they're great PSU's.  One word of warning on buying used PSU's - I've never had any problems with any of them, but literally of all the used ones (from individuals) I've purchased have ALWAYS been missing cords - and typically when I buy the cords to replace the missing ones (always the cords I need, not the molex plugs or other useless ones), it ends up costing almost what a new one would.  The only exception to that is when you buy from forum members, and that's because they're all mining with them anyway, so have the connectors we need.

The good thing about both the 1300G2 and the AX1200i is that they come with 6 PCIe cables, which is what you'll need for the A2.

yeah those are my go to PSU's as well for everything

they are great , plus they even have a plastic piece for running them withoute a board.  I do the same, replace the junk a2 psu's as the fail with those

Strange - doublecheck the connection to the power distribution board - that's the one you plug the main cord into.  Since that's the one that powers the fans, if they're not turning on, then something is up there.  TBH I'm surprised that the PI turns on, since it also receives it's power from there.  Double check all the connection and make sure things are in nice in tight - sometimes even though they have hot glue on them, it doesn't stick to the PCB and it just appears to be connected.

With all of mine, I've never had an issue like that - if you were having issues with power before, then perhaps it was the power distribution board, and not the actual power supply that was the culprit.  If you're good with a multimeter, it would be worth it to go over all the power and ground traces on there.  From what I recall, the power board is super simple, so very easy to test that everything is being passed as it should.

Updated the second post with my power readings. I just noticed that the freq almost equals the amount of watts the miner users 

Thanks for your input MarkAz! I used a Kill-A-Watt for my readings and saw it go up to 1170w max. Once I get the Corsair Link monitoring working I will get a better look at what's going on. Unfortunately it only runs on Windows  

The AX1200i's efficiency is much better on 240v! Unfortunately I am on 120v for now.

If you're used to the stock firmware, it's a pretty big step up - if I do say so myself.  

sorry for delay. Pretty sure we offered you a replacement PSU. Please let me know your order # or ticket #. Thanks!