Xbox Series X Console Won't Turn On - Broken Nexus Connector on Mainboard

[gabri2211]

Hello everyone,
Inside the console there is a small circuit board (see photo) that contains the main power switch, the one on the front.
This circuit board connects to a 10-pin flat cable called NEXUS that terminates on the motherboard.
This NEXUS connector broke.

Can anyone tell me, while waiting for a replacement, if it's possible to turn on the Xbox by disconnecting this circuit board and making some modifications (like adding a small power button) on the motherboard?

The Xbox has a power supply that provides 12 volts on all outputs, so the power supply is fine.

Without this circuit board connected, can you tell me if I should receive any visual or audible indications from the console?

Is it possible that without this board there's no alternative method to turn on the console?

Thanks to anyone who can help.

[Green Probe]

If you have a controller that is already paired to the xbox console, then holding the xbox button on the controller should power on the xbox console. Plugging in a controller with a USB cable and holding the Xbox button may work. The Xbox should make a chime sound when powered on. The fan should also spin.

You should be able to short pin 4 to ground to simulate a power button. There are also debug pads that would be handy for installing a button
This is a page that describes bypassing the Nexus board entirely, and should have just what you need.
https://www.retrosix.wiki/xbox-series-x-daughterboard#3XwIN

[gabri2211]

hello Green Probe. Thanks for your answer
I've already done all the tests you mentioned. The controller is already paired, and it's always worked with the Xbox. I've already checked the site you linked, but it provides incorrect information; it could even provide solutions that damage the Xbox. The instructions say that the 170 resistor is connected to pin 4, but that's not true. At least on my Xbox, there's no connection between pin 4 of the Nexus connector. I tried it with my digital tester! Connecting that point to ground could damage the console. If I test pin 6 on the motherboard, it's not connected to ground as they indicated. I'm not entirely sure they're saying anything useful, but I think they're misleading.
I connected pin 4 of the Nexus to ground, but the Xbox doesn't turn on or make any sound. If you've actually done these tests yourself, please confirm how you did it. Thanks.

[Unspun01]

If your nexus connector is damaged, remove the flex ribbon cable from the connector and try inserting a disc into the drive. The XBOX will turn on automatically. Then you can pair or use a USB connected controller as normal. If a disc is already in the drive, use an unfolded paper clip or other small diameter rigid wire/item to manually eject the disc through the small hole on the side of the disc drive and re-insert the disc and try again.

If the XBOX is otherwise working condition, this will turn on the XBOX.

I had an XBOX series X with a damaged nexus connector on mainboard, and XBOX would not do anything until the flex ribbon cable was removed. Not sure why, but maybe something inside the connector was shorting to ground. These are very delicate and easy to damage. A damaged connector will often make a console appear completely dead.

Also, if you have no luck, use good light and magnifying lens to see if any pins inside the damaged nexus connector are bent or touching each other or the grounded shell of the nexus connecter internally and see if you can bend away from the contact point.

[gabri2211]

Hello Unspun01
Thank you so much for your comment.
I think I'll check this out as soon as possible.
from what you're telling me, it should help me figure out if the Xbox died due to some other problem, or if the switch plate (or flat cable) is the culprit. In that regard, I just ordered the ribbon cable with the plate and connector.

Maybe I'll try to replace it myself, or better yet, have someone who repairs cell phones do it. Unfortunately, no one in my city repairs game consoles.

When I reassembled the Xbox, I forgot to connect that small 12V two-pole connector, and I finally turned on the console, thinking everything was fine. (The connector is the one that connects from the power supply to the motherboard, so it's not visible after inserting the aluminum casing.)

In your opinion, could turning on the Xbox without connecting that connector, have caused the console to malfunction?


Your suggestion comes like a ray of sunshine in the darkness. 🙂🙂🙂
Thanks again. 😊😊😊

[Unspun01]

@gabri2211:

If you did not connect the 12V two-pole connector between the power supply and the motherboard, then the XBOX would not turn on for sure. The power supply provided 12V, 5V, 3.3V as well as ps-on signals, etc. Other voltages are generated on the motherboard from the 12V, 5V or 3.3V.

Without the 2-pole connector attached, you won't really damage anything but If the 12V is missing, so are the lower voltages generated from that 12V power rail.

Many times, the flex ribbon cable is also damaged when the nexus connector is damaged and I do not recommend re-using it. Sometimes the ribbon pins are damaged or bent or broken and can cause other shorts.

Because the flex ribbon is secured to the case with adhesive, the separate power board with the power button is usually ok (doesn't really get pulled on). Usually, it is only the nexus connector on the mainboard which gets damaged.

When replacing a broken/damaged nexus connector, it is helpful to flood the solder pins of the old one with fresh flux and lead solder (lower melting point) and remove it slowly with the heat from a direct contact soldering iron.

When installing a new nexus connector, it is difficult to solder directly and even using a hot air re-work station I only ever re-install a new connector by heating from the bottom with hot air so I do not melt any nearby plastic connectors on the top side by the nexus connector.