V950 - DC successfully disabled!

[UncleMike]

I was able to disable DC on my V950 by making changes only to the handset - no calls to Sprint required. To do this you'll need your MSL/SPC.

Go to the ##DATA# menu (by dialing ##DATA# from the main screen, for those who don't know).
##DATA# More PTT Edit Enter your MSL Core Params Home Carrier ID Set the value to 99 and press OK Press Back repeatedly until the phone restarts

The default value for Home Carrier ID is 1, which (coincidentally?) is the roaming indicator value for Sprint systems in their PRLs. A value of ZERO is apparently invalid (the phone restored a value of 1 upon restart, if it ever saved it in the first place), but my guess is that any value that isn't ONE or ZERO would work fine unless it matches another roaming indicator value in the PRL, which IIRC are 160 and 228.

For anyone interested, this discovery is a result of my efforts to find out why my PRL hacks weren't working as expected (by me, learning as I went). I finally suspected that the open DC connection was preventing the phone from switching away from the EVDO connection it was using, which would then prevent the phone from settling on a CDMA/1x system that wasn't "associated" with the EVDO signal it was still being forced to maintain due to the open DC connection. Without DC enabled, my PRL hacks work exactly as I have thought the should all along.

I only did this within the past hour, so I have no idea whether it will affect my battery life, but I'll report back if battery life changes significantly.

[AsItLies]

Interesting Mike. It certainly seems like there must be something on the phone, like you've indicated, that could turn it off.

Give a shout when you've discovered more. Regards,

[UncleMike]

My assumption right now is that the default mode of operation is that QChat only works when on Sprint's EVDO network. What I believe I have done is fool it onto thinking that it's not actually on Sprint's EVDO network, even though it is. And with the settings I've used, it won't EVER believe that it's on Sprint's EVDO network.

This by itself makes my roaming changes work much better. Prior to this, once the QChat service made its connection, there was no letting go. This open connection caused the phone to refuse to drop the EVDO connection, even though I was forcing roaming on Verizon. What I ended up with in this case, was Voice and SMS on Verizon, and EVDO on Sprint. However, this only worked if I ***ged the PRL, making it appear that Sprint EVDO was co-located with Verizon's CDMA network. Without this ***ging, my attempts at forcing roaming would lead to having only and EVDO connection, and no voice/sms (CDMA) connection.

With this discovery I realize it's likely that very simple PRL changes can be implemented on non-QChat handsets to enable forced roaming, without the complications I was experiencing.