SG135 C2000 BUG

Hello, I recently bought a used SG135 rev.1 which has AVR54 bug (I found out about this bug after I buy it).

For others vendors I found a possible fix, but not for Sophos.

There are two (as far as I know) fixes:

1. Replace a atom c2xxx with C0 revision

2. external pull-up resistor (18.2k to 10k), from LPC_CLKOUT0 or LPC_CLKOUT1, tied to 3.3V

Did someone tried to fix this bug? (I use home license, so I don't have any agreement with Sophos).


Best regards,





  • In reply to Marcelo Clare:

    For now everything is pure speculation. Nobody know were to put resistor.

    Try an idea of Andreas. There could be LPC clock in but on the pictures is not visible if PIN15 is actually connected (need better picture of surroundings of NuvoTon NCT6776F chip).

    Did you try to remove the battery for a few minutes? 



    For now, without scheme will be very hard to tell where to put resistor!

  • In reply to RobertRoskaric:

    Hi Robert,

    Thanks for the information. Please see the picture of the Nuvoton chip. I have tried to remove the battery and start the unit again without success.

  • In reply to Marcelo Clare:

    Hello, on this new pictures is visible, that pin 15 is connected to open pin (in fact in two open pins) and one closed pin which I think goes to C910 (yellow dot). Need better picture of red square. From yellow point it goes up on open pin then right (need better picture) to closed pin (capacitor, resistor) and then left (open) and left (open) and finally to pin 15!

    Red dot is 3.3V. Blue dot is pin15 (IOCLK) - This pin maybe wrong for fix, as is connected to 48Mhz clock???

    EDIT: C910 is connected to X9 (it provides 48MHz clock to pin15!!!). Can someone measure this???



       This is pure speculation and without scheme is almost impossible to say to which pin you/we should add a resistor. I'm not responsible for any way!!

  • In reply to RobertRoskaric:

    The synology fix is straighforward because the LPC clock in question is also used (multiplexed) as GPIO, and these GPIO pins are broken out to some sort of unpopulated connector that is easy to solder.

    One of the unused or unpopulated jumper blocks on the the SG125 board may also be GPIO, but JP7 is the only possible candidate I can see with enough pins, and even then it would have to use the same GPIO pins on the C2000 that are mux'd over the LPC clock pins. It should be easy enough to test though.

    Also, these are older pieces of hardware that have probably been running constantly for 4+ years, in all sorts of conditions. If you have a dead one then the C2000 bug is definitely a possibility, but there are plenty of other ways hardware can fail :) The one I am looking at right now started crashing every few days at first, then every few hours, now it won't POST. Lack of POST is definitely the defining symptom of C2000 fault (can't load BIOS from flash), but the crashing out with increasing frequency isn't, so I think my device may actually have a different fault.


  • Wrote the company which most probably produced/distributed the board DNB1150-PEX Ver: B, asking nice for the schematics or any helpfull info to bypass the intel c2xxx bug. Also mentioned some hints regarding the easy fix for the synology boards. Owning such a synology 2415 by myself and got it back to life soldering just the capacitor. Also helped a friend of mine to fix his syno aswell, which is also back to life. The issue i have with my UTM 125 is most probably the same issue since it behaves like the syno did. So i guess my 125 does only have the c2xxx bug and not any other issue.

    If someone of you needs any more pictures ... i can take them easily from a Board DNB 1150-PEX Ver: B except from the CPU or the DIE since i want to keep the heatsinks where they are
    Not with a good camera, just with mobile (OnePlus 6t)

    BTW: nexcom is selling a similar Product

    Regards, Micha

  • In reply to Michael Arlt:

    Hi Michael,

    Thanks for sharing this information with us.

    Did you manage to install the capacitor on your 125?

    The problem that we have at the moment is the lack of schematics to be able to identify where to install the jump to fix the c2000 bug.


    Marcelo Clare

  • In reply to Marcelo Clare:

    Hey Marcelo,


    i did not play around with the 125 yet. Even when it came to repair the Syno's, i did dig around to not break them. Im not experienced with electronics, measuring and soldering stuff at all. So the only thing i can offer to you guys are informations i probably get. Lets see, if i get something back from them. At least i was asking them kindly for the schematics, but i doubt the will provide.



  • In reply to Michael Arlt:

    Hi Michael, how are you?

    Any news about the schematics?



  • In reply to RobertRoskaric:

    Hi guys,

    after I tried to solder a modwire on the c910 for further testing the conducter path with the condensator was falling apart...

    Since it is not repariable and my SG135 (out of warranty)  is also bricked because of the SC2000 bug, I decided to give the world little bit back and desoldered  the atom cpu and cleaned the BGA pads and re-fluxed them as good as it gets..

    Maybe someone of you find the appropriate trace from the Atom CPU BGA pin to any solder pad around the cpu. I didn't trace anything yet, just desoldered and made some photos so far, nothing else....

    Bild Bild Bild Bild Bild


    Where is Pin 51???? 






    If anyone sees a solution to our problem ( I got also a second SG135 as well with the same error......)  please feel absolutely free to answer this post and share your knowledge and discovery :-)




    P.S.: If you open the images in a new tab, they are even bigger.... if you want I could give you also a direct 24mpixel download link for the pics. Just PM me.

  • Hello, 

    i found this 150 Ohm Resistor in a refurbished SG125.


    With that Fix i brought my broken SG125 back to Life 





  • In reply to DanielSchmitt:

    Hi Daniel,


    thanks a lot for that.  I didn't try it yet, but I will in the next days and report back.


    I uploaded your pic as well, so the forum does not rely on your google link, if thats okay for you?







  • In reply to Harald Meier:

    No Problem Harald,

    good Luck. :)



  • In reply to Harald Meier:

    Great work guys. I hope this is it. Please report it back.

    Best regards,


  • In reply to RobertRoskaric:

    No need to Hope. This is it :)