[Galaxy S 4 Q&A, Help & Troubleshooting] g_gourlay:
Please Help! Driver/Flashing Issue

Hi Guys,

As per my previous post, I wanted to flash the original stock (ZNUAME3) back onto the phone in order to then try re-rooting (as I am experiencing more and more power switch-offs on the device).

Every time I connected the phone though, it said that the device needed to install the “CDC Serial driver”. I downloaded all the USB drivers for the phone and tried again with no success. I.E. I would connect the phone via USB cable, open Odin but would not get a recognised “blue” COM port.

Note: I looked in previous forums re: CDC Serial driver issue - for flashed Galaxy phones - and there has been a LOT of problems … none of which (for me) lead to a positive conclusion.

However, I did read a piece with regards to USB debugging. So I unchecked that box on the phone and – hey presto – the phone stopped trying to install drivers when hooked up to the PC… and when running Odin the device was recognised with the “blue” COM port.

Feeling brave, I then went into Odin in order to try and flash the stock ROM back onto the device (ZNUAME3)… it seemed to work … because the Play Store no longer worked and a lot of the Asian Bloatware came back. However, I was surprised that it did not go back to the original factory settings, that my home screen etc. did not change and that SuperUser/Titanium BU was still installed. But maybe that’s just my poor understanding of such issues – because I am a NOOB!

So, I attempted to re-root the device as per MarrkDaviid’s new procedure … and got to the Iberroots part before I got to a screen that did not match his (and the box allowing me to root was greyed-out – I didn’t take a screen-shot of it as it was all in Chinese – but it was obvious that it wasn’t going to allow me to root the device due to some issue with the phone). I thought maybe that the phone was still rooted?

I put the phone into download mod and was surprised to see that the phone Binary was stated as being CUSTOM and the status was also custom … I thought that this would have changed due to the successful flash of the old stock ROM (can’t supply a screen-shot due to the phone being in donwload mode).

So, I then went back to the old rooting method supplied by Marrk and was able to re-root the device to see if that would improve things at all. At the beginning, it seemed to help … no power-shut-downs and when the device was fully charged, or when I changed WLAN status etc, the device did not shut-down.

Now though, the power shut-downs are BACK, so I want to un-root the device and install SVA 2.5 or 3.0.

Before doing so however, I need to ask the forum the following questions (so I know I am not wasting my time) …

1.	Given the above, can anybody tell me if my previous attempt at re-flashing the original stock ROM (ZNUAME3) worked?

2.	If not, did it not work due to this potential driver issue (CDC Serial)?

3.	If the CDC Serial driver issue is going to be a problem does anybody know how to fix it?

4.	If it is not a driver issue at all, did the previous flash maybe not work because I unchecked the USB debugging box prior to flashing (I really need to be told exactly what USB debugging does with regards to a rooted device)?

5.	Given 1)-4), if I try to flash the CMG2 firmware onto the device – in order to downgrade to the specific firmware which will then allow me to upload SVA 2.5 or 3.0 – can anybody give me a brief explanation of what I should do IF …

•	I try to flash CMG2 via Odin but again get no device recognised

•	Should I uncheck the USB debugging box again or is this a big mistake?

•	What about a factory reset and a wipe of the phone data/Dalvik cache (all of my data is on the memory card anyway and I’m not really worried about app data either)?

Thanks in advance,

Gordon.