Quote Originally Posted by jamesbxue View Post
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So I removed the gupdate.gcd from .System folder. It seems helping a bit. I am able to reboot without connecting to the charger. After restart, the device now prompt "Update Your Device with Garmin Express", then I got end user license agreement, "Cannot unlock maps", "Maps are corrupt...", "Updates the following content was installed to your device: software version 8.50 There are additional updates that require the device to restart. This may take several minutes. Restart now?" After clicking Yes, the device restarts and get into "Installing update files..." but this time with a longer status bar then before (see attached pic).
It seems you have other pending updates loaded via GarminExpress which are also corrupt. These may be for new Voice files or others. Do you remember if you accepted other updates along with firmware and maps? Clearly you must have or it would not be displaying that message and it then getting stuck on the green update bar.

However, it seems stuck there again for the past 15 min, and nothing happened. I plugged it to the wall charger so it doesn't loose power again. I will leave it there over night and see what happen. If nothing changes, what would you suggest I try next?
I doubt it will update successfully no matter how long you wait. If you haven't backed up the internal files do that now. While connected to PC in MSM look for the sub-folder named 'RemoteSW' in .System folder and delete it's entire content of files, then see if it boots normally other than the complaint about maps on start up. If it's ok, connect to GE and update it again making sure there is no interruption to the update process or USB disconnection unless GE tells you to safely disconnect and re-connect as part of the process. Accept the offer to re-load current maps as it seems you also have some corruption there too.

I found this post in the forum - [Only registered and activated users can see links. ], do you think I can follow similar approach to rename the nuvi25x9C4_880.gcd to gupdate.gcd and saves it as \Garmin\GUPDATE.GCD on the device? Is that something worth trying before formating the internal memory with RMPrepUSB?
Don't worry about that now, it's only about basically using WebUpdater (an earlier software than GE) in an 'offline' way to transfer the nuvi25x9C4_880.gcd file to the device where it's placed as "gupdate.gcd". You can do exactly the same by renaming the file you have and copying it into .System yourself. However, GarminExpress will do that anyway when it detects V8.50 and updates by downloading a new copy of V8.80 to install as gupdate.gcd.