Netgear R7800 JTAG: any success connecting this way?

I have an R7800 that's working well, so I bought another one that was questionable/bricked (I thought I might be able to fix / re-flash). Unfortunately, the serial comes up with garbage, and the TFTP procedure does not seem to work. (The router flashes the LAN lights on power-up, then flashes again when the power LED comes on. I get two batches of garbage from the serial, but it doesn't match any baud rate that I can see. And the power-on+reset procedure never causes the power light to blink orange or white -- it's just solid orange.)

I think the only thing left to try is JTAG, if anybody knows where the connection points are. Hopefully it'll be SWD, so I don't have to solder a bunch of wires!

Did you got the JTAG information?

No, I never fixed that router. Sometimes you can find the JTAG information in the FCC filings, or sometimes on the OpenWRT hardware photos, but I didn't have time or energy to work on it. Sorry.