Dangers of downgrading after installing GPS radio (and a little on signing)
 

Ok there is a TON of confusion here, let my try to clear things up.

SPLs: (3 color screen which if you see this you are not bricked!)
0.40 will be overwritten by a flash if an nbh includes an SPL
2.31 will not be overwritten by an nbh (only via OS aka unlocker 0.40)

Radios:
1.xx radios/non-GPS work with 0.40 SPL only
3.xx radios/GPS work with 2.31 only

OS has to match the SPL/Radio as well, but less danger in that section just stuck in SPL

SPLs/Radios/OS are all device specific, do not just repackage nbh files with a vogue ID. There is a modelID embedded for a reason.

CID of radios is less important physically to your device, but you are still running a risk if your carrier does not offer the radio since your warranty will be voided.

Now to clarify my statements on reverting back after GPS:
Short answer: Don't do it!!!!

Details (nobody likes to listen to me saying not to, but here's why I say it):
The 1.xx radios are loaded with a normal nbh header and they can be overwritten by a different radio with no problems.

The 3.xx radios are loaded with a 785 nbh header which is only compatible with the 2.xx SPLs and at least some portions of the radio itself will not be overwritten when reflashed.

The radio actually is what loads the SPL so this is where the compatibility comes into play. When you have the new GPS radio and flash back to a non GPS radio the portion of the radio that loads the SPL does not get overwritten even though the version on the screen will revert to the 1.xx. This isn't always a huge deal when using the 2.xx SPL, because the loaders are compatible still (unless it actually did get overwritten). Once you go back from there to a stock SPL though you very well could get a brick in download mode.

This may not happen all the time there could be different circumstances etc, but i have bricked a few devices and this is what i've come up with.


PS: Also there seems to be confusion about what is actually a "signed" rom i might do a write up on that, but basically if it was dumped or customized (created with dutty or nbhgen) its not signed, if it was at one point on an HTC site as is than it's signed (the ones I call Carrier EXEs).

Re: Dangers of downgrading after installing GPS radio (and a little on signing)
 

Stickied. Thanks for the info ImCokeMan.

Re: Dangers of downgrading after installing GPS radio (and a little on signing)
 

Thanks in advance. I'm about to get a Touch, now that there's a kitchen and although I'm good to go on Apache ROMs the upgrade process on the Touch is so different I have literally been studying for months trying to learn in advance what I'll need to know.

Re: Dangers of downgrading after installing GPS radio (and a little on signing)
 

Thanks, I'm glad I read this today. I have a friend who's Touch I upgraded. But he's not a super-advanced user, and wants to revert back to the stock ROM. I was planning on doing it for him tomorrow, but now I won't. So there's no way to go back to the stock ROM then?

Re: Dangers of downgrading after installing GPS radio (and a little on signing)
 

any idea whether having the new radio will cause problems when the official sprint rom comes out? some people were thinking about reverting back to ensure compatibility with the official upgrade once it comes out.

Re: Dangers of downgrading after installing GPS radio (and a little on signing)
 

Reverting back will not make it any more compatible, that just puts you at risk one more time by flashing an extra radio.

I'm not saying its "impossible" to go back to stock (on surface), but it is risky and even if it appears to work there could be problems down the road. You will not see a write up by me for going back to stock that involves flashing a different radio after the device has a 3.xx a GPS one.

Re: Dangers of downgrading after installing GPS radio (and a little on signing)
 

The new sprint touch official rom will likely be based on a 3.xx radio, so hopefully nothing to worry about.

Re: Dangers of downgrading after installing GPS radio (and a little on signing)
 

thanks for the info mate... and i'm glad that i reverted back to the radio 1.xx and everything went fine using the old unlocker.. but won't do it again :D

Re: Dangers of downgrading after installing GPS radio (and a little on signing)
 

Thanks imcokeman, 2 questions for ya:

1) Why is installing the Titan GPS radio a bad idea, but its "ok" to install the Alltel radio? The Titan radio (3.35) is sprint's radio, so shouldnt that be more compatible with my Sprint Touch than the Alltell 3.37 radio (i currently have 3.37 on my Sprint Touch and am considering "downgrading" to 3.35 because of all of the rave reviews about the increase in GPS performance).

2) Is the 3.35 radio the Titan radio you say to avoid installing? Thank you.

Re: Dangers of downgrading after installing GPS radio (and a little on signing)
 

So those of us "upgrading" to the 3.xx/GPS radios are assuming and hoping that HTC/Sprint will follow with a release being 2.xx+ compatible atleast and /or a radio that "upgrades" or totally replaces our "hacked" 3.xx..

And if that is not the case, we will end up with units with "dirty" radio ROM area? Thus causing possible incompatibilities with official ROM releases and/or end up with bricks?

I am further wondering, if sprint techs will be able to detect this when and if we have to turn in a faulty unit for repair or exchange..

-CC