Hi,
today I tryed to install backfire/trunk/snapshot on a new device WR941ND v5.0,
but when I tryed to flash obtain always the same error :

Error code: 18005
Upgrade unsuccessfully because the version of the upgraded file was incorrect. Please check the file name.

I also tryed to rename the file like the original tp-link but no luck.
Tryed also DD-WRT with the same error.

On firmware page :

Firmware Version:     3.13.31 Build 130105 Rel.66489n
Hardware Version:     WR941ND v5 00000000

Any Ideas ?

obviously the fw you tried are not for v5!

can you open it to attach serial console and/or post pictures with all the markings on the chips well readable?

i am not a dev but i hope these infos could be useful to support your version..

(Last edited by nebbia88 on 21 May 2013, 20:40)

Man,

on  hardware support talking about 5.1 support  : http://wiki.openwrt.org/toh/tp-link/tl-wr941nd

v5.1     -     Backfire 10.03.1     Similar to v4

But now 5.0 is newer!!! Also ddwrt support v.5.x but this is a new device with a prior version.

However installing serail port :
----------------------------------------------------------------------------------------------------------------------
Restarting kernel ...

Bonting Atheros @R924x
Linux version 2.6.31--LSDK-9.2.0_U10.5_dsa.7 (root@localhost.localdomain) (gcc v
ersion 4.3.3 (GCC) ) #29 Sat Jan 5 18:21:11 CST 2013
flash_size passed from bootloader = 4
Ram size passed from bootloader =33554432
CPU revision is: 0001974c (MIPS 74Kc)
ath_sys_frequency: cpu srif ddr srif cpu 535 ddr 400 ahb 200
Determined physical RAM map:
memory: 02000000 @ 00000000 (usable)
Zone PFN ranges:
  Normal   0x00000000 -> 0x00002000
Movable zone start PFN for each node
early_node_map[1] active PFN ranges
    0: 0x00000000 -> 0x00002000
Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 8128
Kernel command line: console=ttyS0,115200 root=31:2 rootfstype=squashfs init=/sb
in/init mtdparts=ath-nor0:128k(u-boot),1024k(kernel),2816k(rootfs),64k(config),6
4k(art) mem=32M
PID hash table entries: 128 (order: 7, 512 bytes)
Dentry cache hash table entries: 4096 (order: 2, 16384 bytes)
Inode-cache hash table entries: 2048 (order: 1, 8192 bytes)
Primary instruction cache 64kB, VIPT, 4-way, linesize 32 bytes.
Primary data cache 32kB, 4-way, VIPT, cache aliases, linesize 32 bytes
Writing ErrCtl register=00000000
Readback ErrCtl register=00000000
Memory: 30060k/32768k available (1775k kernel code, 2708k reserved, 441k data, 1
16k init, 0k highmem)
NR_IRQS:128
plat_time_init: plat time init done
Calibrating delay loop... 267.26 BogoMIPS (lpj=534528)
Mount-cache hash table entries: 512
NET: Registered protocol family 16
bio: create slab <bio-0> at 0
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
NET: Registered protocol family 2
IP route cache hash table entries: 1024 (order: 0, 4096 bytes)
TCP established hash table entries: 1024 (order: 1, 8192 bytes)
TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
TCP: Hash tables configured (established 1024 bind 1024)
TCP reno registered
NET: Registered protocol family 1
ATH GPIOC major 0
squashfs: version 4.0 (2009/01/31) Phillip Lougher
msgmni has been set to 58
io scheduler noop registered
io scheduler deadline registered (default)
Serial: 8250/16550 driver, 1 ports, IRQ sharing disabled
serial8250.0: ttyS0 at MMIO 0xb8020000 (irq = 19) is a 16550A
console [ttyS0] enabled
PPP generic driver version 2.4.2
NET: Registered protocol family 24
5 cmdlinepart partitions found on MTD device ath-nor0
Creating 5 MTD partitions on "ath-nor0":
0x000000000000-0x000000020000 : "u-boot"
0x000000020000-0x000000120000 : "kernel"
0x000000120000-0x0000003e0000 : "rootfs"
0x0000003e0000-0x0000003f0000 : "config"
0x0000003f0000-0x000000400000 : "art"
->Oops: flash id 0x1c3016 .
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
Port Status 1c000004
ath-ehci ath-ehci.0: ATH EHCI
ath-ehci ath-ehci.0: new USB bus registered, assigned bus number 1
ehci_reset Intialize USB CONTROLLER in host mode: 13
ehci_reset Port Status 1c000000
ath-ehci ath-ehci.0: irq 3, io mem 0x1b000000
ehci_reset Intialize USB CONTROLLER in host mode: 13
ehci_reset Port Status 1c000000
ath-ehci ath-ehci.0: USB 2.0 started, EHCI 1.00
usb usb1: configuration #1 chosen from 1 choice
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 1 port detected
Ooops, why the devices couldn't been initialed?
TCP cubic registered
NET: Registered protocol family 17
802.1Q VLAN Support v1.8 Ben Greear <greearb@candelatech.com>
All bugs added by David S. Miller <davem@redhat.com>
athwdt_init: Registering WDT success
ath_otp_init: Registering OTP success
ath_clksw_init: Registering Clock Switch Interface success
VFS: Mounted root (squashfs filesystem) readonly on device 31:2.
Freeing unused kernel memory: 116k freed
usb 1-1: new full speed USB device using ath-ehci and address 2
usb 1-1: device descriptor read/64, error -71
usb 1-1: device descriptor read/64, error -71
init started:  BusyBox v1.01 (2012.11.28-02:55+0000) multi-call binary
usb 1-1: new full speed USB device using ath-ehci and address 3
This Board use 2.6.31
usb 1-1: device descriptor read/64, error -71
xt_time: kernel timezone is -0000
usb 1-1: device descriptor read/64, error -71
nf_conntrack version 0.5.0 (512 buckets, 5120 max)
usb 1-1: new full speed USB device using ath-ehci and address 4
ip_tables: (C) 2000-2006 Netfilter Core Team
insmod: cannot open module `/lib/modules/2.6.31/kernel/iptable_raw.ko': No such
file or directory
usb 1-1: device not accepting address 4, error -71
usb 1-1: new full speed USB device using ath-ehci and address 5
insmod: cannot open module `/lib/modules/2.6.31/kernel/flashid.ko': No such file
or directory
PPPoL2TP kernel driver, V1.0
PPTP driver version 0.8.3
insmod: cannot open module `/lib/modules/2.6.31/kernel/harmony.ko': No such file
or directory
insmod: cannot open module `/lib/modules/2.6.31/kernel/af_key.ko': No such file
or directory
insmod: cannot open module `/lib/modules/2.6.31/kernel/xfrm_user.ko': No such fi
le or directory
insmod: cannot open module `/lib/modules/2.6.31/kernel/xt_mark.ko': No such file
or directory
usb 1-1: device not accepting address 5, error -71
hub 1-0:1.0: unable to enumerate USB device on port 1

Now flash open!
Now flash open!
(none) mips #29 Sat Jan 5 18:21:11 CST 2013 (none)
(none) login: ATHR_GMAC: Length per segment 1536
ATHR_GMAC: fifo cfg 3 01f00140
ATHR_GMAC: RX TASKLET - Pkts per Intr:32
mac:1 Registering S27....
ATHR_GMAC: Max segments per packet :   1
ATHR_GMAC: Max tx descriptor count :   40
ATHR_GMAC: Max rx descriptor count :   128
ATHR_GMAC: Mac capability flags    :   2D82
ATHR_GMAC: RX TASKLET - Pkts per Intr:32
mac:0 Registering S27....
ATHR_GMAC: Max segments per packet :   1
ATHR_GMAC: Max tx descriptor count :   40
ATHR_GMAC: Max rx descriptor count :   128
ATHR_GMAC: Mac capability flags    :   2582
athr_gmac_ring_alloc Allocated 640 at 0x81e80c00
athr_gmac_ring_alloc Allocated 2048 at 0x81ccc000
WASP ----> S27 PHY MDIO
Setting Drop CRC Errors, Pause Frames and Length Error frames
Setting PHY...
athr_gmac_ring_alloc Allocated 640 at 0x81e80800
athr_gmac_ring_alloc Allocated 2048 at 0x81e99800
WASP ----> S27 PHY MDIO
Setting Drop CRC Errors, Pause Frames and Length Error frames
ATHRS27: resetting s27
ATHRS27: s27 reset done
++++ athrs27_igmp_setup once
port0 vid is 0xb000b
port1 vid is 0x30003
port2 vid is 0x50005
port3 vid is 0x70007
port4 vid is 0x90009
++ PVID: 0x0000000b, bitmap: 0x0000001f
++ PVID: 0x00000003, bitmap: 0x0000001f
++ PVID: 0x00000005, bitmap: 0x0000001f
++ PVID: 0x00000007, bitmap: 0x0000001f
++ PVID: 0x00000009, bitmap: 0x0000001f
vtable vid: 0x00000002, bitmap 0x00000003
vtable vid: 0x00000004, bitmap 0x00000005
vtable vid: 0x00000006, bitmap 0x00000007
vtable vid: 0x00000008, bitmap 0x00000009
vtable vid: 0x0000000a, bitmap 0x0000000b
vtable vid: 0x0000000c, bitmap 0x0000000d
vtable vid: 0x0000000e, bitmap 0x0000000f
vtable vid: 0x00000010, bitmap 0x00000011
vtable vid: 0x00000012, bitmap 0x00000013
vtable vid: 0x00000014, bitmap 0x00000015
vtable vid: 0x00000016, bitmap 0x00000017
vtable vid: 0x00000018, bitmap 0x00000019
vtable vid: 0x0000001a, bitmap 0x0000001b
vtable vid: 0x0000001c, bitmap 0x0000001d
vtable vid: 0x0000001e, bitmap 0x0000001f
vtable vid: 0x00000020, bitmap 0x00000021
Setting PHY...
device eth0 entered promiscuous mode
athr_gmac_ring_free Freeing at 0x81e80c00
athr_gmac_ring_free Freeing at 0x81ccc000
athr_gmac_ring_alloc Allocated 640 at 0x81e80c00
athr_gmac_ring_alloc Allocated 2048 at 0x81ea0800
WASP ----> S27 PHY MDIO
Setting Drop CRC Errors, Pause Frames and Length Error frames
Setting PHY...
Now flash open!
athr_gmac_ring_free Freeing at 0x81e80800
athr_gmac_ring_free Freeing at 0x81e99800
athr_gmac_ring_alloc Allocated 640 at 0x81e80800
athr_gmac_ring_alloc Allocated 2048 at 0x81e99000
WASP ----> S27 PHY MDIO
Setting Drop CRC Errors, Pause Frames and Length Error frames
Setting PHY...
====>>>>DHCP start.dhcpc.c,dhcpcStart,772
====>>>>DHCP end.dhcpc.c,dhcpcStart,836
nf_conntrack_rtsp v0.6.21 loading
nf_nat_rtsp v0.6.21 loading
asf: module license 'Proprietary' taints kernel.
Disabling lock debugging due to kernel taint
ath_hal: 0.9.17.1 (AR5416, AR9380, REGOPS_FUNC, WRITE_EEPROM, 11D)
ath_rate_atheros: Copyright (c) 2001-2005 Atheros Communications, Inc, All Right
s Reserved
ath_dev: Copyright (c) 2001-2007 Atheros Communications, Inc, All Rights Reserve
d
ath_ahb: 9.2.0_U10.5_dsa.7 (Atheros/multi-bss)
__ath_attach: Set global_scn[0]
ACBKMinfree = 48
ACBEMinfree = 32
ACVIMinfree = 16
ACVOMinfree = 0
CABMinfree = 48
UAPSDMinfree = 0
Wasp Enterprise mode: 0x00000000
Restoring Cal data from Flash
ath_get_caps[5134] rx chainmask mismatch actual 3 sc_chainmak 0
ath_get_caps[5109] tx chainmask mismatch actual 3 sc_chainmak 0
wifi0: Atheros 9340: mem=0xb8100000, irq=2
====>>>>SystemMode : Normal Router
wlan_vap_create : enter. devhandle=0x81fa82c0, opmode=IEEE80211_M_HOSTAP, flags=
0x1
wlan_vap_create : exit. devhandle=0x81fa82c0, opmode=IEEE80211_M_HOSTAP, flags=0
x1.
VAP device ath0 created
====>>>>wlan: rand channel 5

DES SSID SET=TP-LINK_5D8DFA
ieee80211_ioctl_siwmode: imr.ifm_active=131712, new mode=3, valid=1
Free buffer count 256

sc_txq[0] :
sc_txq[0] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[1] :
sc_txq[1] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[2] :
sc_txq[2] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[3] :
sc_txq[3] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[6] :
sc_txq[6] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[7] :
sc_txq[7] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[8] :
sc_txq[8] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

***********************************
athr_gmac_ring_free Freeing at 0x81e80800
athr_gmac_ring_free Freeing at 0x81e99000
br0: port 1(eth0) entering disabled state
athr_gmac_ring_alloc Allocated 640 at 0x81e80800
athr_gmac_ring_alloc Allocated 2048 at 0x81efb800
WASP ----> S27 PHY MDIO
Setting Drop CRC Errors, Pause Frames and Length Error frames
Setting PHY...
Free buffer count 256

sc_txq[0] :
sc_txq[0] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[1] :
sc_txq[1] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[2] :
sc_txq[2] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[3] :
sc_txq[3] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[6] :
sc_txq[6] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[7] :
sc_txq[7] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[8] :
sc_txq[8] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

***********************************
device ath0 entered promiscuous mode
br0: port 2(ath0) entering forwarding state
ieee80211_ioctl_siwmode: imr.ifm_active=918144, new mode=3, valid=1
br0: port 2(ath0) entering disabled state

DES SSID SET=TP-LINK_5D8DFA
Free buffer count 256

sc_txq[0] :
sc_txq[0] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[1] :
sc_txq[1] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[2] :
sc_txq[2] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[3] :
sc_txq[3] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[6] :
sc_txq[6] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[7] :
sc_txq[7] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

sc_txq[8] :
sc_txq[8] : depth  is 0
aggr_depth is 0 tidBufCount 0  bufQCount 0 axq_cnt 0

***********************************
br0: port 2(ath0) entering forwarding state
====>>>>cmdCtrl open success
====>>>>eventCtrl open success
====>>>>eventCtrl attach success
ATHR_GMAC: GE0 RX DMA ENABLE
ath_paprd_cal PAPRD excessive failure disabling PAPRD now

TL-WR941ND mips #29 Sat Jan 5 18:21:11 CST 2013 (none)
TL-WR941ND login:
---------------------------------------------------------------------------------------------------------

(Last edited by madmax on 22 May 2013, 10:18)

Your CPU is AR9341 according to pictures, none of other revisions of this router has that CPU (according to wiki).
You need to investigate your device, how much flash and memory does it have?
What is flash layout?

Are you stoned ? Read the log

(Last edited by madmax on 22 May 2013, 17:59)

it's similar to wr841nd v8

you can try to flash that image from uboot console..

lolz. The chip is AR9341. I guess I must be stoned too.

i think madmax was referring to the other 2 questions about ram and flash size..

Italian Style

I notice also that wr841 v8 is similar, I'll try to flash tomorrow.

what do you mean??? XD

anyway you should have a mail

I removed the old mail account, resend please

Hi!

I have the same device and I get the same error (18005...) when I try to install OpenWrt. Are there some news about this issue?

Thanks in advance.

I have just put a TL-WR941ND v5.0 router on production with OpenWrt. You can use the same firmware file as TL-WR841N v8, but you need to modify the header in order for the TP-Link web-interface to recognize it as a valid firmware for WR941ND v5.0 hardware.

For the impatient, I have put my modified firmware online: tl-wr941nd_v5.0.bin. MD5 is: db062f1699c760775c5046cc303cba91. It worked perfectly with my router (I did not need to open it at all), but no warranties it will not brick your router, though.

If you want to modify the firmware yourself, do as follows:

1. Download openwrt-ar71xx-generic-tl-wr841n-v8-squashfs-factory.bin

2. Open it in a hex editor. Look at offset 0x40. There should be the following bytes: 08 41 00 08. Modify to: 09 41 00 05

3. Get mktplinkfw.c, md5.c and md5.h. Compile the tool: gcc -Os mktplinkfw.c md5.c -o mktplinkfw.

4. Run: ./mktplinkfw -i *-factory.bin

5. Look for the expected MD5Sum1: expected : e5 67 34 4d 04 99 20 60 f5 76 c6 04 15 81 ab f8

6. Open the hex editor again, go to offset 0x4c, and copy the MD5 above (it should span from offset 0x4c to offset 0x5b).

7. Go and upload the resulting file to firmware upgrade (in TP-Link web-interface). Good luck.

Many thanks to LOM from DD-WRT and to cable007 for reporting this approach worked with DD-WRT.

Hi,

i flashed succesfully my TL-WR941ND v5.0 with "thotypous" modified firmware and it works. :-)
But my problem is that there is any free space to install any packages.
Any ideas why?
Thanks in advance

Ales

Hmm, that is strange, I am pretty sure those devices have the same amount of flash memory. Here is mine after installing some packages (ddns-scripts, qos-scripts, etc.):

root@OpenWrt:~# df -h
Filesystem                Size      Used Available Use% Mounted on
rootfs                    1.1M    848.0K    240.0K  78% /
/dev/root                 2.0M      2.0M         0 100% /rom
tmpfs                    14.3M    768.0K     13.5M   5% /tmp
tmpfs                   512.0K         0    512.0K   0% /dev
/dev/mtdblock3            1.1M    848.0K    240.0K  78% /overlay
overlayfs:/overlay        1.1M    848.0K    240.0K  78% /
root@OpenWrt:~# cat /proc/partitions 
major minor  #blocks  name

  31        0        128 mtdblock0
  31        1        935 mtdblock1
  31        2       2968 mtdblock2
  31        3       1088 mtdblock3
  31        4         64 mtdblock4
  31        5       3904 mtdblock5

Can you run the same commands in your device?

Thank you for your response. :-)
When I run command cat /proc/partitions I have the same numbers as you.
root@OpenWrt:~# cat /proc/partitions
major minor  #blocks  name

  31        0        128 mtdblock0
  31        1        935 mtdblock1
  31        2       2968 mtdblock2
  31        3       1088 mtdblock3
  31        4         64 mtdblock4
  31        5       3904 mtdblock5

and after clean flash of firmware my device show in LuCI on page  System/Software - Free space: 81% (876.00 KB)
but after trying install any package (i.e. openvpn) it show this:

"
Installing openvpn (2.2.2-2) to root...
Downloading http://downloads.openwrt.org/attitude_a … r71xx.ipk.
Installing kmod-tun (3.3.8-1) to root...
Downloading http://downloads.openwrt.org/attitude_a … r71xx.ipk.
Installing libopenssl (1.0.1e-1) to root...
Downloading http://downloads.openwrt.org/attitude_a … r71xx.ipk.
Installing zlib (1.2.7-1) to root...
Downloading http://downloads.openwrt.org/attitude_a … r71xx.ipk.
Installing liblzo (2.06-1) to root...
Downloading http://downloads.openwrt.org/attitude_a … r71xx.ipk.
Configuring kmod-tun.
Configuring liblzo.
Configuring zlib.
Configuring libopenssl.

                    Collected errors:
* extract_archive: Cannot make dir /etc/openvpn/: No space left on device.
* wfopen: /etc/config/openvpn: No space left on device.
* wfopen: /etc/init.d/openvpn: No space left on device.
* wfopen: /lib/upgrade/keep.d/openvpn: No space left on device.
* pkg_write_filelist: Failed to open //usr/lib/opkg/info/openvpn.list: No space left on device.
* opkg_install_pkg: Failed to extract data files for openvpn. Package debris may remain!
* opkg_install_cmd: Cannot install package openvpn.
* opkg_conf_write_status_files: Can't open status file //usr/lib/opkg/status: No space left on device.
* pkg_write_filelist: Failed to open //usr/lib/opkg/info/kmod-tun.list: No space left on device.
* pkg_write_filelist: Failed to open //usr/lib/opkg/info/liblzo.list: No space left on device.
* pkg_write_filelist: Failed to open //usr/lib/opkg/info/zlib.list: No space left on device.
* pkg_write_filelist: Failed to open //usr/lib/opkg/info/libopenssl.list: No space left on device.
"
and then show in LuCI on page  System/Software - Free space: 1% (8.00 KB)

Thank for your help. :-)

Ales

Hi kral_ales,

I think the reason is just that this device does not have enough space for installing OpenVPN. The OpenVPN package and all of its dependencies have around 2MB when unpacked, but the TL-WR941ND, like most TP-Link devices, has only 4MB of total flash memory (that needs to hold u-boot, the kernel and all the system). Even if you removed LuCI and other non-essential software from OpenWRT, you probably would not be able to get enough free space for OpenVPN.

If you want to buy another router for running OpenVPN, I would recommend you to look for a device with at least 8MB of flash at the Table of Hardware. I personally would recommend Mikrotik or Ubiquiti devices, which are relatively cheap and usually easy to find in the market, and have plenty of flash memory.

Regarding your TL-WR941ND, to get the free flash memory space back after trying to install OpenVPN, just uninstall its half-installed package and dependencies.

Hi thotypous,

yes, of course that must be the reason, sorry. :-) I am stupid. :-)
Unfortunately openvpn is mandatory for me so I have to lookround  the new device. Thank you for your recommends and your help. :-)

Ales

i remember that it was possible to have openvpn included in a 4mb image.. maybe was the no-ssl version?

Just did a quick search and found a discussion about this in another thread. Some people say it is still possible to fit OpenVPN if you build your own customized image. The EXTROOT suggestion is also interesting if one wants to have some fun, as an USB connector can probably be soldered to this device. The SoC supports USB, and people already do those hacks in WR841ND v8 units.

I can confirm the firmware works on TL-wr941ND v 5.0000. With the following defects:-
1)PPPOE connection drops at regular interval.
2)Coverage is significantly dropped in comparision to TP-LINK firmware.
So, can't use the most of router. Hence
I reverted back to the original firmware. sad
I hope the firmware appears soon.

Hi sbiomed,

1)

How much time is that regular interval? I am also using PPPoE and I did not perceive any drop in connection stability after changing the router (before that, I had a TL-WR740N also running OpenWRT). My PPPoE uptime is currently 8h 30m. Maybe the unstability also depends on some ISP configuration or behavior which I did not experience.

2)

I did not compare the coverage with stock firmware, but I have been able to cover 3 floors of a building with stable connection using this router. Devices in the second floor were able to lock into the faster bitrates, but those in the third floor could only use slower bitrates. Anyway, I think this coverage is pretty good compared to my previous router.

Please note that almost all TP-Link routers, including WR941ND, come with the regulatory domain locked to a default one (which is very limited) in the EEPROM. The stock firmware ignores this EEPROM setting, altough OpenWRT does not. Try unlocking the regulatory domain as explained in http://wiki.openwrt.org/toh/netgear/wnd … djustment, and setting it to your country then adjusting some wireless settings (such as txpower) using LuCI.

Thank you thotypous for the support.
1. Regular interval  varies from 1min to 10mins. If I changed any settings in the router eg; TX power , then connection drops. At first I thought It was ISP problem, and I changed the next router ie wr741nd which has open wrt(gargoyle) on it, and it was smooth.

2. Isn't it possible that by using firmware of wr841nd v8; only 2 antenna gets activated and 3rd doesn't which causes drop in signal?

Now I am running DD-WRT for WR841nd v 8.
The Tx power is as shown in image:-

(Last edited by sbiomed on 12 Aug 2013, 02:58)

Hm, that is strange, I am using exactly the same firmware image. Maybe next time try checking the System Log to see if it outputs anything related.

The SoC used by WR941NDv5 is the same SoC used by WR841NDv8, whose radio is only 2x2 MIMO, unlike other WR941 hardware revisions which have a 3x3 MIMO radio. Maybe TP-Link ran out of stock on some components and started printing a slightly modified WR841NDv8 and selling it as WR941ND. Technically it is not unethical nor anything, because if you check at their website, WR841ND and WR941ND have exactly the same specifications regarding the radio (they literally copy-pasted the "technical specifications" from one model to the other).

Also, taking a look at the pictures of the WR941NDv5 circuit boards at the first posts of this thread (I did not open my device yet, so I cannot be sure about this one), it appears that two of the three antennas are connected to the same LNA. So it is almost the same thing as taking a WR841NDv8, and putting two antennas in one of the connectors (with correct impedance matching etc.)

In TP-Link website, you can also find the GPL sourcecodes of their official firmware. I took a diff between WR841NDv8 and WR941NDv5 and I did not see any significant changes in kernel sourcecode. The wireless driver is the same. So I doubt the firmware does anything different because of the third antenna, further supporting my hypothesis.

You have a pretty good SNR! I do not know why it is calculating signal quality as being only 63%... 18dBm of txpower is good. I believe it could be increased with some tweaking (but need to check if summing the antenna gain it would not exceed maximum e.i.r.p. on most countries), however in your case you already appear to have good signal figures (SNR and sustained MCS rate).

I installed this firmware to my device (941ND ver 5.0). I found the problem:
- Failsafe not working: Lan interface not working (light's lan or wan not turn on), so I can not connect to device via Ethernet port (lan or wan).

Do anyone else have same problem ?