Bitcoin Forum

(sorry for the size of the pictures)

Previous projects:
My Custom Case Build (https://bitcointalk.org/index.php?topic=259828)
My Custom Gridseed Case Build (https://bitcointalk.org/index.php?topic=499132)

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.

https://i.imgur.com/b7R5U6E.png

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!  :-X (the replacement power supply I eventually received from Innosilicon had the appropriate PCIe connectors)

https://i.imgur.com/RtfbgqO.jpg


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.

https://i.imgur.com/zYdcZsL.jpg


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!

https://i.imgur.com/7xTyP0Z.jpg

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

https://i.imgur.com/8CvMOyZ.jpg

To be continued....

Power results with the AX1200i:

https://i.imgur.com/W1HIf0h.png

I keep it running at 1100 freq. That is already over the 80% rule and I would be uncomfortable running at 1200 freq since that is pushing the AX1200i to its max rating. Thoughts?

The surprising part is that the Mh/W and W/Mh both get better as I get closer to the power supplies max rating?

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

Hey, just wondering if the power supply fixed your problem. Im having a similar problem because my machine runs for about 10 minutes then shuts the fans down. Thanks

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

Hey Mark, is this the PSU you swapped:

http://www.amazon.ca/Supernova-1300G2-Atx12V-1300-watt-120-G2-1300-Xr/dp/B00COIZTZM/ref=pd_sim_sbs_147_2?ie=UTF8&refRID=1FWWSJG58XXGWR59V6WE

Im going to pick one up and see if it solves my problem.

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.

Just ordered, thanks for your help! I'll let you know if it fixes my problem of shutting down after mining for only a couple minutes.

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

I transplanted the EVGA but now only the pie is turning on. The fans don't start. Help?

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.

I replaced the PS also in my a2 110mh term as the original was only running 5 of 8 blades.
Put in an evga 1300, tight fit but work much better now. No reboot in 3 weeks and uses 60watts less at the wall.

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

I'll just toss in my 2c on this - I haven't done a ton of testing on my 110's, but I have been doing power testing on my 88's (I have 12), and there is a pretty wide spread in terms of full-hash power consumption.  I have some as low as 760w, and some as high as 980w - they all are doing almost the same hash, so it must have something to do with the yield on the chips, etc.  On the 110's, I've only played around with power monitoring on two of them - on one, as 1200 it consumes about 1050w-1100w max, so I wouldn't be overly worried about running on an AX1200i.  That was at 110v, so presumably if you're running at 240v, you're get some savings in terms of consumption, and the one I've done some monitoring at 240v actually can be under 1000w at 1200, which is pretty awesome.

Moral of this story, pick up a Watts Up or Kill-A-Watt and measure what your specific machines consumption is.  In any I've tested, 1200 would be more than enough power, but you're definitely closer to 90% instead of 80%, but with a higher quality PSU like the AX, that just translates to slightly lower efficiency.
 

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.

https://i.imgur.com/at48chx.png

How did I miss that? Thanks for making that image! Going to check it out after I read through your thread.

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

I recently had to do a replacement on an A2 Mega power supply (Original was DOA on reciept from Zoomhash).

 I had an EVGA 1300-G2 on hand, tried that second (see below for first) - it fit sorta, but the PCI-E cables had NO clearance vs. the control cables, and the fan didn't line up very well at all with the care fan slots (it's offset about an inch on center, though the quarter inch open space between the PS and the case kinda made it work anyway).
 It worked and was a bit more efficient than the "unknown black PS" in the other Megas I have, but I didn't like the tight bends imposed on the power cables by the lack of clearance, and the fan not lining up with the intake slots on the case was a potential cooling issue.

 Swapped that PS out on my Antminers with one of my Seasonic X1250s I was using on them.

 The Seasonic is

 (1) a good quarter inch shorter than the EVGA
 (2) has PCI-E cable spots that FIT the empty spaces around the control board MUCH better
 (3) Showed efficiency that was identical, give or take measurement limitations, to the EVGA at 1000, 1100, and 1200 Mhz clock rates.


 Both of those PS are quite a bit less $$$ most of the time than the Corsair platinum, but have almost the same efficiency (they bloody near meet 80Plus PLATINUM efficiency specs in all the test reviews I've seen on them), but given the fit issues of the EVGA I have to recommend the Seasonic as a much better choice for an A2 MEGA Terminator replacement PS.

 1000 MH  -  93 MH/s   -  1040 watts
 1100 MH  - 102 MH/s  -  1150 watts
 1200 MH  - 113 MH/s  -  1260 watts

 All power measurments by a Brand 1850 power meter (which seems to read a bit high, though within it's 2% spec).


 And yes, I've noticed quite a range between my 4 MEGA units on power draw at the same clock - and some on hashrate - this unit seems to by my LEAST efficient unit.
 I had swapped the 1300 out of one of the others at one point for a quick test before I tried the EVGA, this unit drew almost 100 watts MORE than the unit the 1300 came from at 1000 MH clock but hashed 2MH/s more too.
 Seems in part to be an issue with how many WORKING cores each unit has, at a guess, more than anything else, but since the UI doesn't show the number of working cores on those units (one thing I wish they had carried over from the 88 non-MEGA firmware) it's hard to tell for sure.

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

One of the fans (middle of the front three) died.  :'(

Anyone know what type of fan it is? The miner is not local so it would save me a trip if anyone knows what kind of fan it is or a suitable replacement. Miner is in a cold environment so the dead fan does not seem to be having much of an effect on heat but would like to replace it anyhow.

Found this post that says they are Delta 12V/1.4A fans? Size?

https://bitcointalk.org/index.php?topic=1141802.msg12258156#msg12258156

Thanks for any help!

Sorry I messed in the post linked above, the Delta is 1.6A and the Nidec is 1.4A.
The size for them is 120x120x38m.

If you are running in a well cooled environment, you can IMHO also use a weaker/slower fan, just make sure the size fits and it's 12VDC.

The below links contain most technical infos for these two models:

http://shop.boxtec.ch/delta-afc1212de-fan-120x120x38mm-12vdc-two-ball-bearing-p-42483.html

http://shop.boxtec.ch/nidec-ta450dc-fan-120x120x38mm-12vdc-two-ball-bearing-p-42482.html

Check also Ebay and AliX for cheaper offers, however I found the ones I buyed on AliX are mostly used.

HTH

Hi Cartman,
where are you from?
If you are in Europe, I could send you a replacement for the cost of p&p.
I have some of those "fans out of hell" left (12cm, 12V 1.4A), an I will never use them again.

Greetings nomoco

Wow, thanks guys!
I am in the US so will just pick up a replacement from Amazon or ebay.

 Lotta "wires crossed" issues, but you did eventually offer me a refund for the dead PS that was a bit more than I was expecting, so it ended up good in the end.

Just a quick update on the dead fan.... As it turns out the fan was not dead! The connection to the board was loose inside the connector. The actual connector was "hot glued" to the board so it would not come loose but the wire inside did. I pushed it back in and it started right up.

Edit: Difference in temps with the middle fan off. Ambient temps are around 20 degrees Celsius.
https://i.imgur.com/wK8yON1.png   https://i.imgur.com/jPVmas9.png