Hello,
did anybody manage it to put the Speedport W 504V (ARV8539PW22) in UART mode? I tried the instructions on the Openwrt Wiki, but that did not work. Putting +3,3 volt on R65 and shorten R80 puts the device alway in SFLASH mode. Or can I use SFLASH to debrick the device with uboot?
Any help is welcome 
I just bricked my 504 while upgrading. It does not respond at the serial port any more, no boot visible....did you have any success with enabling the UART mode since ?
Which side of the R65 did you connect the 3.3V to ? I suppose the one facing the CPU - the other side seems to be connected to ground ? The resistance of R80 seems to be low so that I suspect that this line needs to be pulled to ground. Is this the correct resistance ?
In most common Serial applications, you do not connect the positive power, only ground.
Thanks for the quick reply, more than welcome :). It is certainly correct what you are saying, however, on this page https://openwrt.org/toh/t-com/spw504v there is a link to this page (very similar design) https://openwrt.org/toh/astoria/arv752dpw22#uart_mode, explaining that you select the boot process by pulling the boot_selN pads high or low. Supposing that the numbers correspond, R65 must be pulled up and R80 pulled down. It seems that Unkissedfrog was half successful with that. SFLASH mode occurs as result of the boot_selN set otherwise than UART boot (as I found on a different page going more into detail with this type of devices - but cannot find it any more....
)....
Since I think I damaged the board by trying to get in UART mode, i put it to trash. I didn't get it
Hello
I am trying since days to get my W504V booting again.
Regarding your question i can say that i use a USB2TTL converter named SDS011.
I have wired 4 pins ( out of 5 ) to the pcb. But i don't have any pins pulled up or down.
My problem is, that i can enter whatever i want as a password. The box doesn't enter the command mode. Any hint would be appreciated.
Whatever i enter, after the first key is pressed it continues w/o regard.
ROM VER: 1.0.3
CFG 01
ReadÃ
ROM VER: 1.0.3
CFG 01
Read EEPROM.
=======================================================================
Wireless ADSL IAD DANUBE Loader v1.01.06 build Oct 14 2009 11:46:45
Arcadyan Technology Corporation
=======================================================================
MXIC MX29LV640EB bottom boot 16-bit mode found
Copying boot params.....DONE
Press Space Bar 3 times to enter command mode ...
Get Primary to 0.....123
Please Enter Password:*
Flash Checking Passed.
Thx in advance - Hartmut