Posted: Mon Oct 15, 2018 9:13 Post subject: R7000p Flashing Brick recovery
Apologies if poor form, I posted this in hardware but as I think on it, I wonder if it's better placed here or not? Ultimately I'm hoping for some advice on pin layout OR what do I do to get out of this mess through putty/someothermagic
The original post…...
I'm new to flashing/rebuilding routers, and have immediately gotten myself into a mess. So am here with tail between my legs to ask for help. The end result was meant to be a DD-WRT R7000p, which I got working, but I then couldn't get it to talk to my chromecast, and saw someone saying Tomato was working for them on Chromecast, so I tried that and that is when my router died, on the first day I bought it...
So, I bought a USB TTL adapter and have been attempting to connect via putty, but the issue I have is that Putty just doesn't show anything. So I'm wondering if the Pin layout on the serial header is different on the R7000p than on the R7000. But I can't find any definitive info.
Any ideas what order these pins are (I believe I need to connect TX on the USB device, to RX on the header, and vice versa?)
Or I suppose, any other ideas why my putty might not connect? the router behaviour is that:
All LEDS flash,
First light goes orange for maybe 20-30 seconds at most and then all LEDS flash again and it just loops like that. during the middle of this phase, I can ping the device (using a static IP on my windows device), I have tried tftp which never connects, and Putty just sits on Green cursor suggesting to me that no input is ever incoming.
Well, i have made some progress following a generic guide on serials, connected grnd to pin1, rx to 2 and tx to 3 and lo and behold i see the console output via Putty, sadly i’m still not fixed as i cannot break the boot sequence, it just ignores my ctrl-c and have tried hundreds of times probably.
What happens to the router when you do not have any serial cable connected and try to work as if all is well?
Are you able to ping the router? What does the ping say?
Does any router light glow? When you reboot (no serial cable connected), what is the sequence of lights? _________________ PROFESSIONAL STUDENT my.Mistakes ∝ my.Learning ... provided I have the patience & persistence to learn
Sorry, put that at the obttom of my original post, so suspect that you didn't get that bit.
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All LEDS flash,
First light goes orange for maybe 20-30 seconds at most and then all LEDS flash again and it just loops like that. during the middle of this phase, I can ping the device (using a static IP on my windows device), I have tried tftp which never connects, and Putty just sits on Green cursor suggesting to me that no input is ever incoming.
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I have since then got the Serial output to display through putty, but I still can't get CTRL-C to break in.
Maybe connect the adapter directly to the USB port without using a hub. Seems like that is what it’s plugged into. _________________ I am far from a guru, I'm barely a novice.
Thanks.
Was connected to a USB/Ethernet hub as was using a surface with only one port. have swapped to another machine and connected directly, to no difference unfortuantely.
Have checked the baud rate, and parity/flow controls and are exactly as stated. Have ordered another adapter in case there's something up with this one.
Feel so close, maddening watching it misbehave over and over and can't get it to listen to me! it's like my kids.
Joined: 08 May 2018 Posts: 14246 Location: Texas, USA
Posted: Tue Oct 16, 2018 3:26 Post subject:
Hold CTRL and tap C fast repeatedly as soon as you apply power. The timing is kinda tricky, and it may take a few tries. Just be patient, it'll happen. I don't think you would get serial output if your adapter was suspect, but.
Sorry, put that at the obttom of my original post, so suspect that you didn't get that bit.
You may have resolved this by now.
If not, with kind permission from the experts at this forum, may I suggest that you try out the NMRP Flashing utility of Netgear. If you are able to ping your device and it is a Netgear Router of R series, it may be prudent to try an NMRPFLASH first. No serial cables necessary. Just configure the computer's LAN to 192.168.1.2, connect LAN cable, reboot the router and start to flash as soon as the lights start to dance (ping should be showing TTL=100 when the flashing starts)
NMRP Flash is a great utility from Netgear about which I have not seen any negative reports. I used this to revive my R6400v2 router at least a dozen times + also to revert to Kong's .chk file from a BS build. Found it very useful.
I tried to put a short guide using notes that I had taken from various sites during my first recovery from semi-bricked state. You will find this here ... https://forum.dd-wrt.com/phpBB2/viewtopic.php?p=1139019#1139019 ... pages 4 and 5 are all that you need.
If it does not work, you can continue the serial de-brick method. That's not my forte, so the experts here can continue to guide you on serial de-bricking.
Nothing to lose here, I guess. _________________ PROFESSIONAL STUDENT my.Mistakes ∝ my.Learning ... provided I have the patience & persistence to learn
Thanks again, is very much appreciated that people have taken time to respond.
Unfortunately trying the suggestions made here has yet to fix things. The CTRL-C, trying it with continuous hold down, attempting a world record for button presses in a second and everything in between at every stage from simultaneous start on router power button and ctrl-c to all the way through the 'boot loop' is just not doing anything.
Same with the TFTP attempts, it just gets ignored.
I should get the new serial adapter tomorrow so hopefully that will pay dividends, I did see a post on the openrouter de brick page that mentioned usb device I have not working on input (and they had to fiddle about with disconnecting ground connection which still didn't make things work. (if I switch TX and RX round all the LEDS just stay on all the time and no boot activity happens btw). Don't know if its relevant that the TX light is always on on my adapter, whereas the RX light flashes away merrily as it gets info in.
Look like you connect wrong then it is leading burn cpu or router due NG has no 4.7 k resistor to proctect circuit.
note on any serial console that big trace with capacitor is 3.3v . Two small trace line to cpu is tx and rx.
How to detect it: use multi meter.
2 of 3.3v which one have high resistant to 3.3v around power then it is tx of router.
2 of 0v which one have high resistant to ground then it is rx of router
On NG it is alway 3.3v---GRD---Tx to---Rx from.
But the resistant always higher thousand time compare to a power source as same as 3.3v around. then Tx to -- have fluctuate voltage compare to constant Rx from line. If you had seen this then it used for gpio dectect mode and pull to 3.3v for its purposed. If you not use right tll serial console (over current, over voltage like arduino module or old r232 interface then the change router not boot up or cpu get damage). This is called debug interface bootstraps.
