bricked/boot loop r7800 -- TFTP works but not helping

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sammich
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Joined: 19 Aug 2018
Posts: 2

PostPosted: Sun Aug 19, 2018 7:29    Post subject: bricked/boot loop r7800 -- TFTP works but not helping Reply with quote
Hi:

I'm having frustrating firmware upload issues with my r7800. I'm going to be as detailed as possible just to make sure that I'm not missing anything.

I purchased a used Netgear r7800. Out of the box it was running Netgear firmware version 1.0.2.52. I attached an ethernet cable to port 1 of the router from my MacOS computer.

I downloaded the Kong R7800-factory-to-ddwrt.img file from www.desipro.de/ddwrt/K3-AC-IPQ806X/

I flashed this file to the router through the Web GUI

Right after the flash uploads the router reboots, the power light turns orange and then around 10 seconds later all the port lights flash indicating a reboot.

I waited about 10 minutes and the router was still in boot loop mode.

I assigned my ethernet interface a static 192.168.1.2 address and issued a ping 192.168.1.1 command in terminal. Pinging will show show activity for about 4 packets. Then port lights on the router will flash and the router will reboot.

I downloaded the original firmware R7800-V1.0.2.52.img from the Netgear website then I activate the tftp command prompt. I issue the commands:
connect 192.168.1.1
binary
rexmt 1
timeout 60

I put the router into recovery mode by holding down the reset button and power cycling the device. Once the power led flashes white it takes about 10-15 more seconds until I see steady ping activity on my computer.

I tell tftp put R7800-V1.0.2.52.img. A few seconds later tftp tells me the file has sent and the router starts to reboot. However the router will start going into boot loops again. I check on it 30 minutes later, do a power cycle and it will still boot loop.

My question is, what's going on? Are the boot loops normal when doing a firmware upggrade? Is there any indicator I should see that the firmware is actually being processed after upload? Should I wait longer than 30 minutes? I have tried older firmware files from the netgear page, lede factory.img files, and the img files from www.desipro.de/ddwrt/K3-AC-IPQ806X/NetgearFW/ . All of them give me the same boot loop result.

Any clues would be appreciated!
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Per Yngve Berg
DD-WRT Guru


Joined: 13 Aug 2013
Posts: 6867
Location: Romerike, Norway

PostPosted: Sun Aug 19, 2018 8:03    Post subject: Reply with quote
You have to connect a serial cable to see the boot process.
jerrytouille
DD-WRT Guru


Joined: 11 Dec 2015
Posts: 1304

PostPosted: Sun Aug 19, 2018 14:21    Post subject: Reply with quote
Though serial may be the ultimate solution, r7800 has uboot which is pretty resilient. I usually try everything I can to avoid opening up the sucker. So try tftp each of these 3 latest img firmwares and see which may work.

factory: http://www.downloads.netgear.com/files/GDC/R7800/R7800-V1.0.2.52.zip
dd-wrt: http://desipro.de/ddwrt/K3-AC-IPQ806X/Test/R7800-factory-to-ddwrt.img
openwrt: https://downloads.openwrt.org/releases/18.06.1/targets/ipq806x/generic/openwrt-18.06.1-ipq806x-netgear_r7800-squashfs-factory.img

I also use this tftp software which works best for me:
https://bitbucket.org/phjounin/tftpd64/downloads/tftpd64.462.zip

Good luck bud.

_________________
R7500v2 - 38150M
RT-AC68U - stock

Wifi settings:
ac/n-ng-mixed, noise immunity, short preamble (2.4g), short gi, rts/cts+threshold, ack timing 1350, hfsc-fq_codel
*spectrum cable 100/10Mbps ipv4

QoS sauce:
htb vs hfsc: https://gist.github.com/eqhmcow/939373
fq_codel: https://tools.ietf.org/html/rfc8290
pie: https://tools.ietf.org/html/rfc8033

*Things I shared here is for reference only, ie. it works for me does not mean it will work for you. And yes apparently such disclaimer is needed around here
JornZ
DD-WRT Novice


Joined: 19 Aug 2018
Posts: 3

PostPosted: Sun Aug 19, 2018 15:39    Post subject: Reply with quote
I had the exact same issue with a R7500 v1.
It was also boot looping after flashing the factory to ddwrt file. I tried the one in the regular folder (K3-AC-IPQ806X) and the one in the Test folder on Kong's website. And flashed dd-wrt via the netgear interface and a second time via tftp. The results were the same, boot looping.

I used the instructions on the Netgear website for uploading firmware with tftp and also used the tftp program they link there. I think it's the same one Jerrytouille linked in his post. Link: https://kb.netgear.com/000059633/How-to-upload-firmware-to-a-NETGEAR-router-using-TFTP-client

I too pressed the reset button until the light goes white, after that I could upload the firmware according to the netgear instructions. That worked fine and saved the router.

I concluded there is no way to get dd-wrt working on the R7500 v1 Sad

Maybe we can report this issue somewhere as an official bug?
bushant
DD-WRT Guru


Joined: 18 Nov 2015
Posts: 2036

PostPosted: Sun Aug 19, 2018 16:12    Post subject: Reply with quote
JornZ wrote:
I concluded there is no way to get dd-wrt working on the R7500 v1 Sad
Not saying it works or recommending but have you tried the BS build found here> ftp://ftp.dd-wrt.com/betas/2018/08-14-2018-r36596/netgear-r7500v1/
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JornZ
DD-WRT Novice


Joined: 19 Aug 2018
Posts: 3

PostPosted: Sun Aug 19, 2018 16:40    Post subject: Reply with quote
bushant wrote:
JornZ wrote:
I concluded there is no way to get dd-wrt working on the R7500 v1 Sad
Not saying it works or recommending but have you tried the BS build found here> ftp://ftp.dd-wrt.com/betas/2018/08-14-2018-r36596/netgear-r7500v1/


I did not try that build. The problem is that the factory to ddwrt img puts it into a boot loop and therefore you never get to installing a new build of dd-wrt. Is there a way to skip the initial factory to ddwrt image?
bushant
DD-WRT Guru


Joined: 18 Nov 2015
Posts: 2036

PostPosted: Sun Aug 19, 2018 16:55    Post subject: Reply with quote
AFAIK The factory-ddwrt installs that version of firmware and upgrades (or downgrades) begin from there.
No way of skipping that I don't think. But the <Kong> and BS versions of factory-ddwrt will be different.
Older <Kong> version might work except you can,t find them. If I have it wrong someone will be happy to correct me.

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Per Yngve Berg
DD-WRT Guru


Joined: 13 Aug 2013
Posts: 6867
Location: Romerike, Norway

PostPosted: Sun Aug 19, 2018 17:03    Post subject: Reply with quote
The boot-loop is probably caused by bad hardware. Most likely a bad spot in the Flash Memory.
JornZ
DD-WRT Novice


Joined: 19 Aug 2018
Posts: 3

PostPosted: Sun Aug 19, 2018 17:09    Post subject: Reply with quote
Per Yngve Berg wrote:
The boot-loop is probably caused by bad hardware. Most likely a bad spot in the Flash Memory.


Does that make sense? The Netgear firmware flashes just fine.
Per Yngve Berg
DD-WRT Guru


Joined: 13 Aug 2013
Posts: 6867
Location: Romerike, Norway

PostPosted: Sun Aug 19, 2018 17:17    Post subject: Reply with quote
The Stock FW may not have important code in that address location, making it boot up.
jerrytouille
DD-WRT Guru


Joined: 11 Dec 2015
Posts: 1304

PostPosted: Sun Aug 19, 2018 17:33    Post subject: Reply with quote
I have been successful before to get it to work for my r7800 that I use at work. No need for serial recovery.

- Flash to factory fw
- Enable telnet in 192.168.1.1/debug.htm
- Via telnet: mtd erase kernel, rootfs, netgear, firmware; reboot.
- Flash factory fw again via tftp
- Flash to ddwrt via BS/Kong factory-ddwrt fw.

Cheers.

_________________
R7500v2 - 38150M
RT-AC68U - stock

Wifi settings:
ac/n-ng-mixed, noise immunity, short preamble (2.4g), short gi, rts/cts+threshold, ack timing 1350, hfsc-fq_codel
*spectrum cable 100/10Mbps ipv4

QoS sauce:
htb vs hfsc: https://gist.github.com/eqhmcow/939373
fq_codel: https://tools.ietf.org/html/rfc8290
pie: https://tools.ietf.org/html/rfc8033

*Things I shared here is for reference only, ie. it works for me does not mean it will work for you. And yes apparently such disclaimer is needed around here


Last edited by jerrytouille on Sun Aug 19, 2018 20:32; edited 1 time in total
grc
DD-WRT User


Joined: 11 Jul 2018
Posts: 122

PostPosted: Sun Aug 19, 2018 19:59    Post subject: Reply with quote
Same issue here with r7500v1. Tried several BS and Kong builds.

jerrytouille wrote:
- Enable telnet in 192.168.1.1/debug.htm


this doesn't work
sammich
DD-WRT Novice


Joined: 19 Aug 2018
Posts: 2

PostPosted: Mon Aug 20, 2018 6:19    Post subject: Reply with quote
Update: I figured out whats going on. kind of.

tl;dr: this router is just screwed up. i think it's overheating.

I last left it plugged into my Mac and I gave up for the night after TFTP flashing the oldest Netgear firmware ( 1.0.0.28 ) for the umpteeth time.

After reading all the suggestions this afternoon I decide to bring it down to where my Windows desktop computer is to try a different tftp client. When I plugged it in to the outlet, to my fustrating surprise the power light started flashing white and it magically booted into the Netgear firmware. WTF.

Being the masochist that I am I decide to see what would happen if I upgraded the Netgear firmware to the current version (1.0.2.46) through the Web GUI. Again it boot loops. I then tried to TFTP flash the firmware file again and again it boot loops.

I then decide to unplug it, wait a moment and turn it on again. After about 5 minutes I turn it on and it boots into the firmware no problem.

I leave it turned on (but not configured) while running other errands and when I come back about 20-30 minutes later I find the router boot looping again.

I'm guessing there was nothing wrong with the flashing process. Something is overheating and causing the boot loops. It's odd because it's barely been turned on for any length of time. It feels warm but not abnormally hot.

I'm going to attempt to return this. Thanks guys for all your helpful suggestions.
ddaniel51
DD-WRT Guru


Joined: 19 Feb 2013
Posts: 1464

PostPosted: Mon Aug 20, 2018 15:19    Post subject: Reply with quote
Per Yngve Berg wrote:
The boot-loop is probably caused by bad hardware. Most likely a bad spot in the Flash Memory.


I lost my 7800 due to a bad flash chip. It had run fine for a year and then went poof during an update.

Solution? Gave it to my son to play with and went to all R9000's. He managed to erase the wrong partition and relegated it to door stop.

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