1.0 Xbox does not complete powerup.

[ea2000]

This is a 1.0 Xbox that was found with a dead 110v PSU, most likely plugged into 220v. I swapped the PSU with a good one. When I press the power button I get rapid flashing green light, no fans, no boot, no FRAG. It had a leaky clock cap with some messed up resistors near the cap which were replaced from a doner board after cleaning the area, no change. Traces look ok. I swapped the 5 1500uf caps with new ones, no change. Power at the first N FET input is 5v when the power on button is pressed and around 1.8v on the output. I swapped the fet from a doner board, no change. Voltage on the two resistors near the yellow power button cable show 3.5v and drop to around 2.5v when pressing the power button.

Not sure where to go from here...

[MadMartigan]

Have you checked for trace rot on the bottom of the board where the clock capacitor is located? Here are the points to track down and test continuity. 
 

https://imgur.com/a/9HoxSlq

[ea2000]

18 hours ago, MadMartigan said:

Have you checked for trace rot on the bottom of the board where the clock capacitor is located? Here are the points to track down and test continuity. 
 

https://imgur.com/a/9HoxSlq

I checked C1-C4, all are good. C4 & C5 from the bottom two photos (next to R6V2) are not on the 1.0 motherboard.

[ea2000]

Here is a short video showing the issue.

 

 

[KaosEngineer]

4 hours ago, ea2000 said:

Here is a short video showing the issue.

 

 

The new PSU you installed has both v1.0/1.1 and v1.2-1.4 connectors.  Verify that the 3.3Vdc standby level is present at the motherboard's power supply connector. (Brown wired pin on the connector below)

The voltage level at the resistor that has the power button signal going through it to the SMC (PIC processor) should drop to 0Vdc when the power button is pressed and return to ~3.3Vdc when the button is not depressed.

[Bowlsnapper]

5 minutes ago, KaosEngineer said:

The new PSU you installed has both v1.0/1.1 and v1.2-1.4 connectors.  Verify that the 3.3Vdc standby level is present at the motherboard's power supply connector. (Brown wired pin on the connector below)

The voltage level at the resistor that has the power button signal going through it to the SMC (PIC processor) should drop to 0Vdc when the power button is pressed and return to ~3.3Vdc when the button is not depressed.

.... It has single row and double row connectors? I'm confused, Kaos... I've never seen that before but there it plainly is in the video!

I remember trying to use a 1.6 power supply with a 1.4 board on accident and the USB power (port LEDs) was just on constantly. If you're using in improper power supply, I guess interesting things can result.

[ea2000]

1 hour ago, Bowlsnapper said:

.... It has single row and double row connectors? I'm confused, Kaos... I've never seen that before but there it plainly is in the video!

I remember trying to use a 1.6 power supply with a 1.4 board on accident and the USB power (port LEDs) was just on constantly. If you're using in improper power supply, I guess interesting things can result.

The original PSU from this Xbox was dead. I'm using a known good PSU which is one I ordered a long time ago from China. It has dual adapters and is multi-voltage (110-220). It does not work on a 1.6, however.

[Bowlsnapper]

21 minutes ago, ea2000 said:

The original PSU from this Xbox was dead. I'm using a known good PSU which is one I ordered a long time ago from China. It has dual adapters and is multi-voltage (110-220). It does not work on a 1.6, however.

Must be a custom job. That would make a great test PSU. I think the 1.6 has a different pinout even with the same connector.

[ea2000]

The voltages measure as expected. If you watch closely in the video you'll see it flash green, stop flashing, then flash again before I press the button. Each one of these flashes appears to be a boot attempt. Some times it does three sets of green flashes and then FRAGs, but the fans never turn on. When it does FRAG it stays "on" until I press the button again to shut it off. If I measure voltages while its FRAGing there is 12v at the plug on the motherboard, but it doesn't seem to get very far since the fans don't spin and there is no drive activity if I connect them. The 5v does seem to get around the board as well as the 3.3v. The CPU heats up also.

[ea2000]

7 minutes ago, Thairanny said:

I would try to repair the original broken PSU if you can. It might not be as hard as you think, if you still have it.

Yeah, good idea. I'll take a look at it. Never trust a PSU with a lot of connectors.

[Bowlsnapper]

4 minutes ago, ea2000 said:

The voltages measure as expected. If you watch closely in the video you'll see it flash green, stop flashing, then flash again before I press the button. Each one of these flashes appears to be a boot attempt. Some times it does three sets of green flashes and then FRAGs, but the fans never turn on. When it does FRAG it stays "on" until I press the button again to shut it off. If I measure voltages while its FRAGing there is 12v at the plug on the motherboard, but it doesn't seem to get very far since the fans don't spin and there is no drive activity if I connect them. The 5v does seem to get around the board as well as the 3.3v. The CPU heats up also.

It DOES look like a half-assed FRAG, basically. Like something is flashing or at least trying to during the frag. Almost like the RED isn't working right or something.

[ea2000]

31 minutes ago, Bowlsnapper said:

Must be a custom job. That would make a great test PSU. I think the 1.6 has a different pinout even with the same connector.

I'm pretty sure it's one of these. It even came with a 1.6 adapter which I no longer have:
https://www.reddit.com/media?url=https%3A%2F%2Fpreview.redd.it%2Fe8mz66vvox631.png%3Fwidth%3D640%26format%3Dpng%26auto%3Dwebp%26s%3Dba7570dcd9c3bbe06fed4f2fa66239582b6c0cd3

[lOgIcAl]

You need a good solid working original xbox V1.0 / V1.1 power supply. It's the only way to move forward for testing IMO.
You can probably pick one up cheap on the bay or borrow one from a known working box. They don't cost very much, if you've wasted an hour then you've already spent minimum £10/$10+ of your time .... it's not worth chasing otherwise.

[lOgIcAl]

Also, looks like it had an X3 chip fitted at some point. Best check the LPC port etc for any shorts/stray bridges too.

[Bowlsnapper]

4 hours ago, lOgIcAl said:

You need a good solid working original xbox V1.0 / V1.1 power supply. It's the only way to move forward for testing IMO.
You can probably pick one up cheap on the bay or borrow one from a known working box. They don't cost very much, if you've wasted an hour then you've already spent minimum £10/$10+ of your time .... it's not worth chasing otherwise.

I agree with this. That's something I would at least try.

4 hours ago, lOgIcAl said:

Also, looks like it had an X3 chip fitted at some point. Best check the LPC port etc for any shorts/stray bridges too.

I noticed that too. The double sided tape on the left of the front panel. That whole interior looks pretty worn out. See if the LPC is borked.

[ea2000]

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:

 

Edited January 8 by ea2000

[Marty]

5 hours ago, ea2000 said:

 I had swapped cases to rule out a power button issue

I hope you didn't swap with a 1.6 case....

[ea2000]

6 hours ago, Marty said:

I hope you didn't swap with a 1.6 case....

No, and I think it's the other way around. A 1.6 in a non 1.6 case will short on the center screw terminal.

[FrostyMaGee]

15 hours ago, 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:

 

Just for the hell of it did you replace the C1G1 and C2F3 caps?

[ea2000]

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?

 

[ea2000]

39 minutes ago, Thairanny said:

Compared to a PC, I feel like this is what happens when you are Overclocking it and it fails, then reboots and fails again, then reboots and fails again, and either turns off or resets the bios. Uausally it's bad ram, bad overclock on the ram, bad OC on the CPU, or the Voltage you set for the CPU was too high. Anything like that really. It happens when your PSU sucks too.

 

I would say it still has power delivery issues or some regulatory component is not functioning properly. Please correct me if I'm wrong, but I think the FOXLINK PSU's are the worst out of all the Xbox ones. Odds are your troubles may start there.

The PSU came off another 1.0 console that is working just fine, so I'm pretty confident it's not the PSU.

[ea2000]

44 minutes ago, Thairanny said:

No clue, but it is positive progress. Have you tried it with the HDD and DVD drive installed?

Yes, no change.

[ea2000]

43 minutes ago, Thairanny said:

Compared to a PC, I feel like this is what happens when you are Overclocking it and it fails, then reboots and fails again, then reboots and fails again, and either turns off or resets the bios. Uausally it's bad ram, bad overclock on the ram, bad OC on the CPU, or the Voltage you set for the CPU was too high. Anything like that really. It happens when your PSU sucks too.

 

I would say it still has power delivery issues or some regulatory component is not functioning properly. Please correct me if I'm wrong, but I think the FOXLINK PSU's are the worst out of all the Xbox ones. Odds are your troubles may start there.

I've read elsewhere about the FOXLINK PSUs being crap, but I don't see where this is coming from. The unit looks extremely well built and the components appear to be good quality.

[ea2000]

1 hour ago, Thairanny said:

I'm sure you have new thermal paste already, right?

I only did the CPU. I didn't think this could cause a FRAG, but I'll do the GPU just in case...

[ea2000]

I dumped the EEPROM and everything looks good: