XBOX powers off uncommanded

[arfows]

I've run out of Caps and need to reorder.  Where are your favorite places to get decent Caps at the cheapest prices?  I've ordered from digikey and mouser but the shipping usually costs almost as much as the Caps.

What is the recommended ripple current amperage at low and high or does it not matter?  Same with impedance, does that matter?

Any brands you'd stay away from?

Thanks!

[Marty]

If you're going to test caps, they shouldn't be soldered to the motherboard.

[FrostyMaGee]

I would stick with Mouser or Digikey. Yeah the shipping can be a little high but I end up buying a lot of caps at a time since they’re ones I know I’ll need. Additionally you know the quality of the part you’re getting. With less trusted sources you never know what you’re going to get really. It’s entirely up to you though. As for brands I like Panasonic, rubycon, and nichicon. I tend to do the first two more than anything. You’ll want to get a 3300 microfarad 6.3v with a temperature rating of at least 105C and Low ESR. The size ranges from 10x20mm or 10x25mm. I don’t recall the impedance but lower is better. Seems like the ripple current was around 2.9-3.2A. I’m sure others can add more info than me though and any preferences and recommendations they have. 

[arfows]

Thanks.  How many mOhms is considered low ESR?

[FrostyMaGee]

The low esr I have are 18mOhms but I’ve also had some low esr at 12mOhms. I believe they were a smaller size capacitor than the 3300 microfarad though. 
 

Anyone else want to weigh in on that?

[KaosEngineer]

On 10/30/2023 at 2:22 AM, arfows said:

XBOX 1.2 TSOP flashed with Cerbios that will power up and run for about 2 minutes and then just powers itself off

Hit power button again and it powers on right away.

This time it stays on for less time...and each iteration of this powers it on for less time than previously until its only on for 15 seconds or so

After I let it sit for a half day, it'll run again for a couple minutes and then exhibit the same behavior.

This occurs regardless if the DVD is connected during power on sequence (have DVD check bypassed in Cerbios).  This sounds like a classic Cap issue...or could it be a power supply issue?  To rule out one or the other, what is the easiest way to determine what is giving/causing the power off signal?

Thanks!

Leaking clock capacitor damaged power button signal trace running to the System Management Controller (SMC) - PIC processor on the motherboard.

The power button signal is carried on the outside / bottom trace seen in the above image.

[arfows]

 Is an ESR of less than 30 mOhms good enough?  

Is low ESR critical for power supply caps if I replace some of those as well?  One of my Power supply's voltages vary by about 10% when the xbox is left at idle for a while.  Assume that's a sign of a bad capacitor.

Yeah, it exhiits that trace rot behavior problem -  powers on by either plugging it in or via eject button...they current theory is that the surmised electrolytic leak is also what is causing the board to shut down uncommanded at at shorter intervals each time.

[Bowlsnapper]

10 minutes ago, arfows said:

 Is an ESR of less than 30 mOhms good enough?  

Is low ESR critical for power supply caps if I replace some of those as well?  One of my Power supply's voltages vary by about 10% when the xbox is left at idle for a while.  Assume that's a sign of a bad capacitor.

Yeah, it exhiits that trace rot behavior problem -  powers on by either plugging it in or via eject button...they current theory is that the surmised electrolytic leak is also what is causing the board to shut down uncommanded at at shorter intervals each time.

Yeah, trace rot isn't the only problem. It leaks into a lot of components also, specifically all the transistors around the cap.

[arfows]

Found a site that said anything less than 100 mOhms was considered low ESR.  Given Frosty's earlier comment (thank you!) about using 18...I'll probably try to stick somewhere close to that, less than 30 at least I think will be some good options unless somebody has experience with Caps that didn't work or failed quickly in that range.

Edited November 5, 2023 by arfows
addl info

[Marty]

Although trace rot can be caused by a leaking capacitor's fluids, the primary reason for trace rot (which is generally in a specific area of the motherboard) is due to corrosion...because there's insufficient lacquer covering the copper traces. This is probably due to how the board were sprayed in the factory. It's a problem generally not seen on 1.6's so I'd assume they adjusted their manufacture process.

I've done trace repair on two of my XBOX's....they were a 1.2 and a 1.4.

[Bowlsnapper]

20 minutes ago, Marty said:

Although trace rot can be caused by a leaking capacitor's fluids, the primary reason for trace rot (which is generally in a specific area of the motherboard) is due to corrosion...because there's insufficient lacquer covering the copper traces. This is probably due to how the board were sprayed in the factory. It's a problem generally not seen on 1.6's so I'd assume they adjusted their manufacture process.

I've done trace repair on two of my XBOX's....they were a 1.2 and a 1.4.

I've always wondered how the rot can even happen if solder mask is in place. It should be impossible, shouldn't it?

[FrostyMaGee]

52 minutes ago, Marty said:

Although trace rot can be caused by a leaking capacitor's fluids, the primary reason for trace rot (which is generally in a specific area of the motherboard) is due to corrosion...because there's insufficient lacquer covering the copper traces. This is probably due to how the board were sprayed in the factory. It's a problem generally not seen on 1.6's so I'd assume they adjusted their manufacture process.

I've done trace repair on two of my XBOX's....they were a 1.2 and a 1.4.

It does feel like a manufacturing issue. Especially in the 1.2-1.4 vers. The five I’ve had to do have all been in that version range and almost exclusively in the same area or directly adjacent. Annoying. 

[FrostyMaGee]

10 hours ago, arfows said:

Found a site that said anything less than 100 mOhms was considered low ESR.  Given Frosty's earlier comment (thank you!) about using 18...I'll probably try to stick somewhere close to that, less than 30 at least I think will be some good options unless somebody has experience with Caps that didn't work or failed quickly in that range.

Thanks! Glad to be of help. I looked at some other cap orders I had and some of the ripple currents were 2.47A so I’ll amend my previous statement and say 2.47-3.2A on the ripple current range if that helps when you’re ordering.

Yeah the “low ESR” range seems to be slightly subjective from manufacturers based on some values I’ve seen. That’s why I definitely wanted to check some I’ve had to see what it actually said for that value. 
 

Best of luck in your replacements and trace repair. Hope it gets your Xboxes back to functioning properly!