[Q] Flash I9505 without going in download mode?

Hi,

I've got my good old 9505 I bought right at release on which the Volume UP button (or more likely whatever hardware it's connected to, as the button itself works perfectly normally) has become stuck pressed.
That causes a little problem - I can't enter Download mode anymore (Normal power up enters recovery due to the stuck key, Vol Down cancels Recovery and boots normally).

I had a custom ROM and recovery on it, and in order to send it for repair I obviously want to put it back to stock status, so I have reflashed a stock MI8 image I found using ODIN, using the custom recovery's "Reboot in Download mode" command.
Now the problem is I have bad luck and likely had an incompatible modem, and after booting even with cache/data wiped I have the Samsung keyboard crashing constantly and WiFi won't work.

Of course restoring the stock image wiped my custom recovery, so I can't use the same trick to get back into Download mode and reflash another modem.
I can't use Mobile ODIN or reboot menus with a "Reboot Download" option, as those requires root, but... rooting needs Download mode.

I can connect to Kies, but for my region it unfortunately says the current ROM is already the latest.

Does someone have an idea I didn't think about?

I found something that suggested it, however while I've painfully been able to go enable USB debugging (with the UI that locks and the "Samsung Keyboard has stopped" messages that appear between nearly every tap) adb devices returns nothing. Maybe the same issues cause debugging to fail too...

OK, found an app called "Kingo Android Root" that works from the PC through adb, and managed to root it again. It took some time to connect, but once it did it went through the procedure OK.
Then I could transfer the apk for "Quick Boot" to the phone through MTP, and its reboot menu worked to reboot in Download mode
Got a new modem flashed, and WiFi is back. The Samsung keyboard is still crashing every 5 secs, but I'll just try reflashing the OS, never know...

Yes, it's just a matter of finding the right stock ROM... :\

OK, the MKF ROM for my country I found here works perfectly fine.
Issue closed then, hope this will serve other people who might end up in a similar situation

Now to see how the service center reacts to a stock config but with Knox flag set...

Good news, received my S4 after a one week turnaround (shipping included), and it was repaired under warranty even with the Knox bit set and me having dismantled it (thanks Sammy for not putting "warranty void" stickers, pretty much the first manufacturer I see who doesn't!)