Having the same exact issue. Firmware same.. CPU soft different.
Was having the same issue as the poster on my TRX-1 brand new in the mail. My firmware is currently 1.3 as well, and cpu soft is at 5.1 latest. Device refuses to load any new dsp updates from 1.3 to the latest new 3.0. Have tried everything from checking device mgr, to comm port settings, to using a microSD adapter and formating my microSD card to Fat32 in 32byte sectors as instructed by the app to no avail. Even tried to reformat through a card adapter in my laptop's card reader through the app thinking perhaps a corrupt file was the cause. Also to no avail. Tried different USB ports and cords to no avail. Have attempted to update from different formats direct download from Whistler Groups support section, as well as through the TRX-1 app. to no avail. Thinking mayber perhaps just one of the downloads itself was corrupted. Scanner is stuck constantly at... I even tried a higher end brand new 32gb microSD card that was known to be working in my GOPro Hero III after a format. Still to no avail. Below is what it shows once it get's to this page it's dead in the water.
SIIII FTGA D2 II Bat logo
Whistler
TRX-1
Handheld
Digital
Trunking Scanner
Scanner goes through all other initial processes fine it seems but once this splash screen is hit it fails every time. Like a blue screen of death. It just freezes and fails. If I attempt to tap the power button sometimes I will get a quick glimpse of what should follow with the Scan lists wording etc. But that is soon gone in roughly 2 seconds or less followed by a Power OFF logo. Then the scanner shuts right on down. Very nice glitch. Wondering how it got by quality control honestly? But I did contact Whistler Groups all awesome technicians and they said to just send the unit back in asap as this is obviously a bigger issue which I am leaving to do now as we speak. Back to Bentonville AR this one goes. I suggest you do the same. Nothing seems to be resolving this issue, and as tech savvy as the two of us are i'm willing to be there is a broken piece of software in the protocol there somewhere. It would seem. The way it just gets stuck in what seems an ENDLESS loop to that one page. Where it just constantly shows that, and nothing but that.
Alpine-