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Re: Recovering a bricked RNDX4000 (NVX)

dtarin
Luminary

Recovering a bricked RNDX4000 (NVX)

So I was messing around with an old NVX and decided to experiment with upgrading it to OS6.  I didn't realize OS6 was 64 bit until after I bricked the NVX.  (oops!)

 

Anyway, based on reading up on other experiences it appears this situation is recoverable by accessing the NAS via the serial port in the back. 

I have had some success connecting but am having some issues and I need your guys' help figuring things out. 


1) What is the serial pinout on the NVX?  Everything I've seen by googling seems to reference the NV+'s square serial port.  The NVX has a horizontal serial port.

[  * * * *  ]


Looking at the back of the unit counting from the left, This is what I think the four pins are.

[ 1 2 3 4 ]

 

1.  3V
2.  TX
3.  RX
4.  GND

 

Can anyone confirm?

 

2)
I have a USB to TTL adapter and connected only the TX and RX cables and I am able to see boot messages and a command prompt. (Should I connect GND or the power pin??)

 

When I type on the terminal, I don't get a response from the NAS so I'm not sure the commands are being interpreted. Characters do appear to be echoed to the terminal as I see what I type.

 

What settings do I need to have on my terminal in order to have the NAS receive and respond to commands entered in the terminal? I am using PUTTY on windows but if there's a better app for use with serial connections let me know.

 

Thanks!

Message 1 of 12

Accepted Solutions
dtarin
Luminary

Re: Recovering a bricked RNDX4000 (NVX)

Muah ha haa!  UNBRICKED.

I did it in a crazy sort of way by using TWO USB sticks.

1) 240MB stick  (yes megabytes!  lol, it was the only other stick I had)

2) 4 GB stick

They both had the usb recovery added on them.

The 240MB stick was plugged in front.  It booted but always failed to continue.  I was curious so I went into and modified the syslinux.cfg line that said 'default Normal' to 'default OSReinstall'.  I did the same to the 4GB stick.

 

I tried both the 240MB and 4GB stick individually at first in the front.  The 240MB always booted but failed.  The 4GB one didn't do much even though they both had the exact same recovery on them.  (not sure why) 


Then I tried the boot up process again with the 240MB stick.  I held the backup button and powered up the unit.  I watched the output from my serial connection and when I saw,  "initializing....."

I immediately plugged in the second 4GB stick IN THE BACK USB port.  My thinking was.. well, if it can't find the front USB stick, then maybe when it searches it will find the one in the back.

And whoala!  The trick effin' worked! And it reloaded the OS, and did the power down thing. 

I'm back in business!

 

Kinda nice that since I set the recovery to do an OSReinstall, instead of a factory default, all my settings stayed intact.

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Message 7 of 12

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dtarin
Luminary

Re: Recovering a bricked RNDX4000 (NVX)

I'm using a CP2102 USB to UART bridge and I did a loopback test on it and it seems to be working.  (With PuTTY, I did a ctr-E test and saw a PuTTY response.)

 

This is good and bad.  Good that the device looks like it's working and bad that it's probably now due to the nvx not responding.  

 

 

Message 2 of 12
StephenB
Guru

Re: Recovering a bricked RNDX4000 (NVX)

I believe the serial port parameters are 9600 8n1 XON/XOFF.

 

Not sure where you are looking for recovery, but there is a fairly long thread here:

Unfortunately it wasn't fully successful.  Only Netgear can repair a VPD.  Although if you used @Sandshark's procedure to back it up first, you should be able to restore your backup copy. 

Message 3 of 12
dtarin
Luminary

Re: Recovering a bricked RNDX4000 (NVX)

Yep I think I have the parameters correct, just as you mentioned.  I am able to see output from the NAS but just can't get it to respond to commands from my terminal. 

 

I did see @frankie0p's post but the pinout diagram there didn't make much sense to me as I don't have a ttl cable with those colors.  

 

(1)    (2)    (3)          (4)

Bl      Gr    Wh       Not Connected

 

I just have a bridge on which I can add any jumpers of any color of the rainbow.   Anyway, after looking at it again, I think this is what the pins are:

 

1) Ground

2) TX

3) RX

4) power (3v3 or 5v not sure but doesn't matter, no need to connect)

 

I'll try this setup next time I have time to go play in the server room (i.e. basement closet, lol) and hopefully that's all it was to get the NAS to respond to commands.

 

p.s.  I don't have anything to back up, this was a completely clean NAS so thankfully, there's no data that needs to be recovered. 

Message 4 of 12
dtarin
Luminary

Re: Recovering a bricked RNDX4000 (NVX)


@StephenB wrote:

I believe the serial port parameters are 9600 8n1 XON/XOFF.

 

Not sure where you are looking for recovery, but there is a fairly long thread here:

Unfortunately it wasn't fully successful.  Only Netgear can repair a VPD.  Although if you used @Sandshark's procedure to back it up first, you should be able to restore your backup copy. 


@StephenB.. VPD?  

 

virtual private database?

very picky database?

voracious pizza daemon?

 

Message 5 of 12
dtarin
Luminary

Re: Recovering a bricked RNDX4000 (NVX)

OK!  We have ignition! 

 

# uname -r
2.6.37.3.RNx86_32.1.1
#

 

The pinout for future reference when using a CP2102 UART Bridge is as follows:

 

Looking at the nas from the back.  Counting from left (with the usb ports on the right)  these are the pins. 

 

[   1     2     3    4  ]

 

1 - GND

2 - RX

3 - TX

4 - Power

 

To connect to the CP2102 here's the connection:

 

NAS <------------------->  CP2102

1      <------------------->  GND

2      <------------------->  TXD

3      <------------------->  RXD

4       (not connected)

 

Now on to the challenge of restoring the device!  

 

Message 6 of 12
dtarin
Luminary

Re: Recovering a bricked RNDX4000 (NVX)

Muah ha haa!  UNBRICKED.

I did it in a crazy sort of way by using TWO USB sticks.

1) 240MB stick  (yes megabytes!  lol, it was the only other stick I had)

2) 4 GB stick

They both had the usb recovery added on them.

The 240MB stick was plugged in front.  It booted but always failed to continue.  I was curious so I went into and modified the syslinux.cfg line that said 'default Normal' to 'default OSReinstall'.  I did the same to the 4GB stick.

 

I tried both the 240MB and 4GB stick individually at first in the front.  The 240MB always booted but failed.  The 4GB one didn't do much even though they both had the exact same recovery on them.  (not sure why) 


Then I tried the boot up process again with the 240MB stick.  I held the backup button and powered up the unit.  I watched the output from my serial connection and when I saw,  "initializing....."

I immediately plugged in the second 4GB stick IN THE BACK USB port.  My thinking was.. well, if it can't find the front USB stick, then maybe when it searches it will find the one in the back.

And whoala!  The trick effin' worked! And it reloaded the OS, and did the power down thing. 

I'm back in business!

 

Kinda nice that since I set the recovery to do an OSReinstall, instead of a factory default, all my settings stayed intact.

Message 7 of 12
dtarin
Luminary

Re: Recovering a bricked RNDX4000 (NVX)

I still can't believe that worked... 

Message 8 of 12
StephenB
Guru

Re: Recovering a bricked RNDX4000 (NVX)

I'm glad you were able to bring the NVX back to life.


@dtarin wrote:

@StephenB.. VPD?  

 

virtual private database?

very picky database?

voracious pizza daemon?

 


Vendor Product Data file.

 

This is an encrypted and signed file in the boot flash that contains the model information and serial number of the NAS.  So it can't be re-created by anyone other than Netgear. It is used by the OS in configuring your unit, and likely also was intended to prevent people from running ReadyNas firmware on other (non-ReadyNAS) platforms. 

 

We have seen some cases where this file gets corrupted during failed OS-6 conversions - the good news is that this didn't happen with your NVX.

 

Message 9 of 12
dtarin
Luminary

Re: Recovering a bricked RNDX4000 (NVX)

ahhh.. good to know!  Thanks!

Message 10 of 12
dtarin
Luminary

Re: Recovering a bricked RNDX4000 (NVX)

@StephenB side question on the VPD.  What's the process to back that up and restore if needed?

 

I'm going to be monkeying with the NVX some more so that sounds like something worth having a restore plan for!

Message 11 of 12
StephenB
Guru

Re: Recovering a bricked RNDX4000 (NVX)


@dtarin wrote:

@StephenB side question on the VPD.  What's the process to back that up and restore if needed?

 

I'm going to be monkeying with the NVX some more so that sounds like something worth having a restore plan for!


@Sandshark posted the procedure here:

His procedure works for both OS 4.2.x and OS-6.

Message 12 of 12
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