1.0 Xbox does not complete powerup.

[ea2000]

18 minutes ago, Thairanny said:

TBH maybe its got bad ram. It might just be too far gone, it is a 1.0 with previous mods and years of use right? I've had a ton of DDR2 die over the last decade, use and age.

Sigh, you may be right. I'm assuming there's no way to test these RAM modules, right? If I added more RAM to the board could that allow the console to boot or does the first 64MB need to be good? Can it boot with at least 64MB working from any of the 8 banks? I've seen when they do 128MB upgrades and run XBlast to test the ram, sometimes some of the banks fail, but the console boots just fine.

[KaosEngineer]

1 hour ago, ea2000 said:

Sigh, you may be right. I'm assuming there's no way to test these RAM modules, right? If I added more RAM to the board could that allow the console to boot or does the first 64MB need to be good? Can it boot with at least 64MB working from any of the 8 banks? I've seen when they do 128MB upgrades and run XBlast to test the ram, sometimes some of the banks fail, but the console boots just fine.

The first 64MBs has to be good. 

IIRC, XBlast OS's RAM test only tests/checks the additional 64MBs installed when a 128MB upgrade is done.

 

There is an Xbox application, xbmemcheck, that tests RAM but if your console is not even booting to a replacement dashboard, you won't be able to run it.

xbmemcheck.rar

 

Edit: You may be able to run it by creating a boot disc with this app.  Make an XISO disc image with QWIX or C-Xbox Tool then burn it to DVD-R media.  Buring to CD-RW media may work if your Xbox's DVD drive is one that can read them.

The Xbox BIOS attempts to load/run the default.xbe file read from the DVD drive before loading the dashboard off the hard drive.

[KaosEngineer]

On 1/8/2024 at 8:13 AM, ea2000 said:

I pulled a good original PSU from a working console. Also, I had swapped cases to rule out a power button issue, but now the motherboard and PSU are in the original case. This console had an Aladdin modchip installed, which I've removed while troubleshooting. The D0 is not currently grounded. The console now FRAGs consistantly, but still no 12v on the motherboard. Here is a new video showing some voltages:

KaoeEngineer Edit: Youtube video removed to save space:  

Check the voltage level between pins 2 (+ probe) and 3 (- probe) or 2 (+ probe) and 1 (- probe) of the the PWM fan speed controller.

The FANPWM control signal is an output of the PIC processor (System Management Controller) at pin #13.  It is a digital signal. To view it, use an oscilloscope or logic analyzer.

From an old leaked Microsoft Xbox Repair Powerpoint slide presentation:

PWM Fan Speed Control Circuit

[Bowlsnapper]

On 1/9/2024 at 6:50 AM, ea2000 said:

I managed to solve the 12v issue. It was a via near C8C5. I made sure to use a thick wire just in case. Fans are spinning now, but the console still FRAGs. I tried installing the modchip incase the stock BIOS is bad, but no change. I tested the modchip on a good console and it boots up just fine. I also tried with the drives connected, still FRAGs. As I mentioned before, the five 1500uf caps were replaced with new ones. The other caps look good and don't usually go bad, but what do you guys recommend?

 

Congrats on fixing the 12V issue... I think the passives on this board are trashed... I dunno man...

[ea2000]

For all you Delta PSU fans, I managed to repair the original psu. No change in the FRAG as I expected. I'll try to boot the memory test from a CD-RW next.