Xbox 360S Trinity
RGH3 Ring of Light No Dashboard

August 17, 2022

The latest Xbox 360 Trinity to get the RGH3 treatment seemed to go well for the wiring, NAND dump and reload but I was not getting a normal boot process to the dashboard.  Xell started properly, but when I tried to boot into the dashboard I would see the normal green ring of light circle for a while and then it would go out, and the centre LED would light solid green but there would be no display.

Front view of an open Xbox 360 Trinity with the power light on.

Solid green LED but no dashboard.

Because I was able to get a screen image with Xell I figured that the HDMI port, wire and connection to the TV were all OK, but I also tried using an official Xbox 360 composite AV cable just to confirm there was no display.

Given the issues with the previous Trinity where I needed to recreate the flash image and reflash the NAND, I decided this would make a good next step.  I first placed the original updflash.bin onto a USB key and inserted into the system to let Xell perform the flashing.  During the process there was a message about some potential bad blocks, but this was followed by a message suggesting there wasn't a problem after all.  Confusing to be sure!  Some reading online suggested that when J-Runner encounters bad blocks the blocks are remapped and everything should be fine, so I hoped that rawflash would do the same.

Xbox 360 system booted into Xell Reloaded running the rawflash utility to write an updated NAND.

After the flash was completed the system was rebooted but the behavior didn't change.  I decided to try a few more flash and reboot cycles to see if eventually all of the 'bad blocks' were remapped and I could get a clean flash run.  Each time after the flash I rebooted the system to test if things were working.  Although the 'bad block' errors eventually stopped there was no success in booting to the dashboard.

The next step was to recreate the RGH3 NAND file and ensure that the proper options were selected and try flashing again.  The new updflash.bin was created without any errors, and flashing completed in Xell without any bad blocks, but the system still would not boot to the dashboard.

With the software side of things appearing to be correct it was time to revisit with RGH3 wiring.  All of the solder points were in the right place, and they were all secure, but something clearly wasn't right so I decided to start with the C5R35 point which is the easiest to mess up.

RGH3 wiring on the underside of an Xbox 360 main board.

I remember reading that wire length could be a problem in certain circumstances, and although I was quite happy with the routing for the wires I decided that I could make some changes and shorten them a little.  I desoldered the C5R35 point, performed some more careful scraping of the via and examined under the microscope to validate that everything looked OK.  I then changed the wire routing slightly and I was able to trim about 1cm from the wire.  I rebooted the console, but no change.

Although I had the recommended 3K resistor in place on the PLL line, I know that the range goes as high as 10K.  I swapped out the 3K resistor for a 10K and retested, but there was no change.  Since upping the resistance didn't make a difference and I was already at the bottom end of the normally suggested range, I decided to go lower with a 1K resistor.

1K resistor soldered to a Microsoft Xbox 360 main board.

The clouds parted, the sun shone and low and behold the system booted!

Dashlaunch utility running on an Xbox 360 system showing the CPU Fan Speed Override as well as system information.

My takeaway from this issue is that while 3K-10K may be the normal resistance range for Trinity consoles other factors may come into play and require a different value.  Luckily swapping out resistors is easy although you do need to be careful with the solder points if you repeatedly need to reheat the the FTV21 point so as not to lift the via.