Xbox 360 S Trinity power issue

[Hellstorm32]

Hello everyone!

I recently discovered this forum and created my account today in the hopes that someone will be able to help me.

I have an Xbox 360 S (Trinity model) that was missing numerous voltages on the motherboard. I discovered using a thermal camera that a certain component, labeled U5A1 on the board was heating up to over 125 degrees Celsius. This component is an SMD component, package size SOT-23-5. The case markings are ADLRUU. I tested continuity to ground on the pins for this little guy and discovered pins 2 and 3 had continuity to ground. I removed the component and the pad underneath pin 3 had lost it's continuity to ground. I believe the component is bad. I have been unable to source this component based off the case markings, which leads me to believe that the markings do not identify the item and may just be a lot code. There is another of these components near this one, I believe they may both be LDO chips that take 5v DC in and have the output voltage set by using resistors in circuit on one of the pins.

I would like to ask if someone can assist me in either identifying this component or sourcing a replacement that I can purchase from either Mouser or Digi-Key. My web searches have found some people in Mexico had success in replacing this chip with a larger component, however this involves using jumper wires and mounting the component on the board by itself. I know there has to be a cleaner way to do it, hence the reason why I'm here.

I have plugged in the power supply to read the voltages of the system in standby mode and recorded the values I read on a picture I took of the pads without the component. I have attached this picture for everyone's review along with a picture of the components before removal. I have also attached a picture of the board area before removing the component as well as a picture I found during my web searches that supposedly shows what the pin values are with a good component.



If anyone can lend their knowledge to a newbie I would appreciate it greatly. I've been doing board repairs on electronics, mostly video game consoles for around 13 months now and am really interested in growing with this field. Thank you!

 

[Harald Kapp]

The chip marked ADLRUU could be a MAX6319.

 

[Hellstorm32]

Thank you for commenting and your assistence. I actually found this myself yesterday doing some research. I even called Maxim Integrated to verify my information that the top mark code matched their part number. The MAX6319 is a supervisor chip, this version without a watchdog, which verifies a specific voltage. This means that this chip is not responsible for setting the 3.3v, it's responsible for supervising it. If specified voltage is not present, then sends an output which most of the time is read by software to print an error or alarm. It appears that according to the top mark, this specific chip may be the MAX6319LHUK31C-T. The 31 in the part number designates 3.1V, which according to the datasheet the chip is looking for between 3.034 V and 3.157 V apparently at the VCC. I called tech suport at Maxim Integrated yesterday and went through the datasheet with them. Regardless of the function of the chip, the chip in this console had pin 3 shorted to ground (pin 2), so the chip is bad. I'm unable to find a replacement through Mouser or Digikey due to the chip being obsoleted in their stock. Last thing I wasnt to do is order a reel of 4500 of them from Maxim. I think I did find them at one vendor. I have requested a quote yesterday. I have yet to hear back today.

 

[Hellstorm32]

New development,

I have 3 or 4 of the same model of Xbox 360 S that I've purchased broken to repair or use for spare parts. One of these models ended up being a trinity with the same chip at U5A1. I discovered that testing standby voltages while this chip is off gives me 1.3v where pin 3 would be, which is consistent with my findings from the console I'm attempting to repair. Once a good chip was installed that I removed from a working but exceptionally dirty system I received 3.3v on pin 3 during standby. However, the system still would not power on. I discovered that I'm still missing numerous voltages. Most notably, 5v in many areas. This is strange to me, since 5v feeds the ADLR chip that is now supplying the 3.3v. Scouring the web I came across a post that someone made in a facebook forum that explained the exact situation I'm running into on an Xbox 360 E (which is the next consecutive model version after the S and the final release of the console). They had success in changing the southbridge chip. I will be removing this BGA in the near future and swapping it with another to test this method.