KnC Titan Miner Repair


Hi Lightfoot,

I have searched the entire internet and finally found someone who can help me out.
I have the following problem.
When i start knc miner batch 1 the mining application page is not visible anymore.The rest of the pages (status, system, advanced and backup) are visible.
Do you know what causes this problem?
I hope you can help me out.
Thanks in advance.



Really, that’s weird. Does it mine? Can you ssh into it as username pi, password whatever the admin password is then type screen -r?

Did you try re-loading the code onto another SD card? Does the green light come on the side of the controller (not the 3 green lights on the Pi board)?



thanks for the quick responds.
Yes, i can login as admin, green light is also visible.
The cube is detected, the advanced page is also visible.
The cube is not mining due to the fact the mining pool cant be set because the mining page is not visible.



Hm. Probably a code error. Get the Titan 2.00 image, put it on an SD card using win32diskimager, then boot up the titan and go.


Just wanted to give feedback on the help lightfoot gave me with (4) Titan cubes a few weeks ago. All 4 were dead when I sent them to him, and he returned them in a few days, they have been mining around 250-270mh since!
I am SOOOOO Freaking happy with his work. I totally recommend him! THANKS again lightfoot!


Hi guys!

Just a very important announcement: If you have broken the plastic molex around your PCIe plugs and are running cubes by plugging straight into the pins please note you are on very thin ice.

If you ever plug in a cube and miss the pins so that the top 3 pins on the Titan go into the bottom three pins on the power plug, you will instantly do the following:

  1. Blow up the cube.
  2. Blow up the controller
  3. Blow up every other cube on the controller permanently.

This mistake basically results in a 120 amp ground loop that will flow through the lines that control the hashing engine hotel circuits. When they go from their normal 1.2 volts up to 12 volts they blow up and this is impossible to fix.

So please be careful plugging in cubes. Or just have the plugs replaced, a mistake will result in a 100% un-fixable Titan stack.



did that mod on I think 3 cubes…so extra paranoid…always double check.

(or better yet just leave well enough alone and mine once the mod is done…never take off the KNC Y adapter :slight_smile:


All it takes is one mistake in the dark. Also the next thing to burn is the pins to the Titan, that’s a real mess to fix…

I’ve taken to using nickel plugs these days, they might work a bit better, will have to test at some point under heavy loads.


A good fix someone with a big soldering iron can try is to remove the 6pin plug altogether
an solder big fat wires directly to the relative pads (mind the polarity!)
This will ensure no more fried connectors and voltage drop from poor contact…


Use preheat. Otherwise you wreck vias and i hate fixing that. Better send to me for new connectors.


Yeah of course, forgot about that…
I used a PCB preheat plate under the boards.




I have a few titans that might need repair as well.
I’m new here so I don’t think I could send PM yet (or I just missed on how to do it). But I think I could reply to PM, @lightfoot could you send me details on how to get started? Thanks


Sure, I’ll send you a PM. Look at your A icon in top left, you will see a number and my PM.



guys looking for a knc Neptune controller ? anyone got one for sale ?


Lightfoot, I just purchased a knc titan 4 cube setup off ebay. The first issue we had was two of the fans would not spin for us. We went ahead and installed new fans and they work great. We are having an issue with the controller board. None of those light flashing sequences you mentioned have been displayed on the unit.

When we boot the device, the screen on the controller board is blank.

Here is what the code says:
Configuring TPS65217 try 1 (then 2 then 3)
Waiting PGOOD for too long
DC/DC converter configuration failed!

After a few attempts like this, the device reboots.

Any ideas on what we should do? If this is a controller board issue, and the ebay seller cannot resolve it, I would like to send the board out to you.


Well, first make sure all cube are unplugged from the controller board. Then try
io-pwr init

And see what you get.

If you see an error message it’s the FPGA. Send it in and measure the resistance from pins 4,6,8 to ground (10) and don’t use a cube with resistance under about 800 ohms. I can fix boards with shorts on pins 4,8 but not 6.


Hello Lightfoot,

It looks like there’s a problem with my Titan KNC controller board. LCD screen is not showing anything, it is lighting up, but that’s pretty much it led light don’t light up at all. Also I connected Ethernet cable and it seems that system doesn’t see it. I cant find the device true the rooter. Could it be that my controller is toast? The way I see it is that the bit on the main controller board is not receiving power, for the led indicators are not lighting up and device does not see the Ethernet cable. I could be wrong. Might-be you have an idea what is wrong with it, and if so then please PM me your address and give me an idea of how much it would cost to get it up and running again. Looking forward to hear from you! Happy X-mas to you and everyone on the forum! Thank you in advance!


Hm. If the Pi on the top isn’t powering on (lights on back of the Pi and the board underneath it, do any of them come on) then it could need a new old model Rpi or a beaglebone. I’ll PM you shipping address.


Hi, how do I send you a PM? Im new here and cant see it. I have 150 titan cubes and alot of them are running on 1-2 dies. Do you stil do repairs? Im sending from Norway.
BR Lars