Preliminary: Download and install the ASUS Firmware Restoration Utility. Download the ASUS RT-N66U firmware from their support page -- https://www.asus.com/us/Networking/RTN66U/HelpDesk_Download/ Connect the router to your PC via a UTP Ethernet cable. (Disconnect any other wireless or wired connections you may have to your PC.)
Step 1) Hold down the reset button and power up and keep holding it down for 30 seconds (some resources say 10 seconds but I held it down for 30). This step, ostensibly, puts the router in "rescue mode" according to various sources and the power lamp will blink slowly. The router given to me was, evidently, already in this mode, but I did this step anyway.
Step 2) Launch the ASUS Firmware Restoration Utility and install the firmware.
It will take several minutes to complete the firmware load.
You should always consider that nobody is really knowing the 100% correct answer, especially only 3h after your posting. Please allow mother earth to do one full rotation (24h), so you message can reach users all over the world.
I'd also say, I was kinda shocked. I would have surmised that someone who purchased a bricked router knew how to use those tools already. Some people get upset that you're babying them or treating them like a fool. You'd be surprised.
In addition, you didn't ask for an example.
I simply connect the serial cable. Depending on how your device is bricked depends on the procedure.
You were already told about the bootloader. If you see the bootloader when connected so serial, you should be able to proceed from there.
I don't know the TFTP procedure for your specific model.
@dkwalton The devicpage https://openwrt.org/toh/asus/rt-n66u is lacking information regarding unbricking / installation. If you succeed with unbricking, the devicepage would be the ideal place to add the unbricking information.
Re: "Yet you insult. Guess you are seeking a fully-written manual.
Let's just wait for the eatrh to rotate, then.
BTW... I also added.
Depending on how your device is bricked depends on the procedure.
So perhaps you should provide more details in the meantime, too.".
Oh for crying out loud.
Back off. What is your.problem? I have insulted no one. Evidently you missed the details which are given in the second sentence of the topic post. I am doing the best I can, which evidently does not measure up to your standards.
Please feel free to never answer any posts I may make here in future. I find you presumptive, personally insulting and unhelpful. Clever by far though with your silly "take downs." You must live for such.
This sort of nonsense is NOT why I joined this forum. To bicker with someone I don't even know when all I seek is to share and garner knowledge. If you want to spend your time chastising folks, join a Yahoo chat room.
If this is how this forum is going to go, then I have only one more question: How do I delete my account?
In any case unless you at least have a working bootloader the UART (serial connection) will not work.
In my original post I wasn't offering any suggestions on how to un-brick any device. I was just politely pointing out your error/confusion. That UART (serial) and JTAG are unrelated so that you may educate yourself in that area as a minimum and hopefully anyone else reading this PUBLIC forum doesn't git mislead by your post.
Many people refer to serial as TTL this is possibly confusing. It should be refereed to as UART or just Serial comms.
TTL refers to the voltage so a 5V UART is a TTL UART
but in the case of 3.3V UART that is technically CMOS.
So what is JTAG for
When a manufacture puts together a device it is generally blank. Since there is no bootlaoder they need/use JTAG to program the ROM/Flash with the bootloader and any other software or data they desire. They can even use it to test the hardware by programming temporary tools for the purpose of testing and diagnosing hardware. In summary it is an engineering tool used in manufacturing electronics.
So JTAG can be helpful to you if you have the skill and technical knowledge of your hardware to re-manufacture it if the bootloader has been bricked not just or OEM or OpenWrt firmware.
Sure, let me remote your machine; and I'll fix all up it for you.
I am sure you would. Run along now. I am done with you, dear heart. If I ever desire to have an extended conversation with a sociopathic troll again I'll be sure to look you up. Please don't take that as an insult. It is, "Just the facts Ma'am."
Thank you mbo2o and Das U-Boot. I guess I do know what a boot loader is since I have long worked with such building Windows machines (and DEC machines before that). I just don't get it with consumer/business routers which to me are arcane and confusing. I suppose if I went ahead and built an OpenBSD machine with a couple/three wired and wireless NICS this whole routing business would make more a lot sense to me. (In fact, I should have done that years ago. Maybe this should be my next step.)
Related Subject You Might Address? --.
There is this open source thing called Tftpd. It comes in 32 bit and 64 bit flavors. Evidently it can be used as a sort of universal firmware loader for various and sundry consumer/business routers. Do you know anything about this utility?