MSI Prestige 15 ms-16S6 won't power

[Dr.d]

Good Afternoon mon2. Okay, just a couple things. First I was having troubles with matching up the (pin numbers) and their functions with the Data Sheet and the IC TPS65994AD that I have on the motherboard. After researching it, there appears to be 2 types of IC in for that particular USB PD Controller (with the same part number!) Mouser...DigiKey and other all seem to only have the IC package that has all the pins on the outside edge of the IC. The one on this board are under the IC and don't appear to have corresponding numbers that I can match to the Texas Instruments datasheet. I can't seem to find one with my particular IC version (with contacts scattered under the IC. So, cannot find the LDO outputs from this IC or what points under the pin to to any outside MOSFETS. Any ideas or thoughts? Thank you kindly

[Dr.d]

[mon2]

Take a few side view pics of this controller that is on your board. I think you have the same as the one stocked at Mouser / DK = QFN package (quad flat pack).

The package with the balls underneath = BGA = Ball grid array.

[Dr.d]

Okay...I was able to get a good look at the package and it is a BGA for sure. It's definitely not the QFN IC...nothing at all on the sides.

Also, an update. I went ahead and looked at the Balls on the Boardview. it lists VCC3V3_FLASH and a VCC1V5_FLASH. If you blow up the U22 IC on the BD it gives those descriptions so I'm assuming that is the LDO voltages output. The 3V3 v is present but the 1V5 v has nothing coming out from the IC. I traced the 3V3 to many of the locations and I came to a road block at R548! The 3V3 goes to the pad, but there is no resistor there! I don't know if its part of this motherboard revision or if somehow it's just got knocked off somehow? I've taken a picture of it for you. Let me know what you think. I can't quite tell if something was there or not! Thank you

[Dr.d]

[Dr.d]

It's weird that neither Digikey or Mouser carry the TPS65994 in the BGA package. Only the QFN!

As far as that missing R548 resistor. I've got to think it should be there, but I know I wasn't over there in the location to accidently dislodge or lose it. I could put in another, but don't know the value without a schematic. Any ideas there of what I could use? Crazy

[mon2]

Use your meter in resistance mode and trace where the track from this missing part travels onto the flash ic. Which pin mates with this trace?

[Dr.d]

mon2, the other side of that missing Resistor R548 goes to pin 8 of that Flash IC (U35). It says its 3VSUS_TBT0_1 .

[Dr.d]

Any thoughts on if you think that missing resistor could be the culprit? Or do you think it's maybe the U22 bga PD IC? I'd like to try and put in a resistor and give it a try......I just not sure what value to use! What do you think? Thank you

[mon2]

R548 is a very good find. This missing part can be a showstopper. Weird that they have applied a series resistor here but the value would have to be relatively low in resistance. Perhaps a value of 33R (ohms) or less. In a pinch, you can even consider shorting the 2 pads @ R548.

R548 has pin #8 (Vcc = power to the flash IC) and other side is the 3v3 rail. With this part missing, the flash chip (U35) is not being powered.

[Dr.d]

Excellent...thank you for your help and input. Is the Flash UC basically same as a BIOS chip? Same or similar functions? I will look to put in a low resistance resistor in there and then let you know the results. Thanks again mon2

[mon2]

This appears to be a lower density flash so it will be component that holds the firmware for te EC or maybe a power delivery controller. Either way, it is required. You can short these pads or insert a 10R or 33R resistor here.

[Dr.d]

Good Morning mon2. Wanted to give you an update. I added a 10R resistor to the missing resistor and unfortunately it didn't make a difference. Still reading 5v and no current draw. The 3.3v is getting to the flash chip now though, but can't see any difference.

One thing that I noticed. I believe I should have 1.5v LDO, coming from the U22 TPS65994 chip and I don't. I only have the3.3v LDO. According to the Boardview, 1.5v is at H1, G2 and G3 and goes to C625. Once side of C625 is ground and the other goes to the U22 (H1, G2, G3) and it measures 6 ohms with no voltage on it. I checked the resistor and its good. I removed U22 and the short goes away. Do you think that is a problem? Weird that I do not see H1, G2, G3 going to anything other than C625. Do you think without the 1.5v the handshake will not happen and will not turn on the 19v?

If the chip should have the 1.5v there Vcc1V5_flash and its not. I got to think maybe the U22 chip needs replaced. Would you concur with that thinking? Thank you

[Dr.d]

Good afternoon mon2. Do you happen to have a good source for the U22 BGA IC other than China? Digikey and mouser only seem to have the QFN version of that PD chip unfortunately. I didn't want to have to wait a month or more. Thank you

[Dr.d]

So I'm just looking for ideas of where to go from here. Right now, I have 5v going into the U22 PD IC (TPS65994 AD) BGA . I'm getting 3V3 output. Found a missing resistor going to the Flash IC but it didin't change anything. Still no current draw from the adapter on the motherboard. The 1V5 output has nothing coming out. Meter in resistance shows 6 ohm short to ground. It disappears when the U22 is removed. I'm thinking U22 IC is the problem....and thoughts please?? Thank you again. ** Also, looking for a local USA source for the U22 IC its BGA.

[Dr.d]

Hey mon2.... Just wanted to update you. I'm going to try replacing the PC IC , U22. I cannot find it anywhere but in China. Probably a month out in getting it. I can't believe nobody stocks the BGA version of this chip! Oh well, without schematics I'm out of ideas on this one. Thanks

[parkhayoun]

See 6 variations of boardviews for this model in my paid sub. Which version is yours? Look for the silk screen on the board and post their pics here.

Hi mon2, I'm also struggling with the same problem on MSI Prestige 15 which version of the board is 16s31.

I already replaced the whole motherboard and it doesn't boot. I think I have to check the schematic to force boot the laptop bypassing the power without PD and the battery.
So, If you are okay, Can I get a schematic of this board If you have? I'm begging..

I'm looking forward to you.

[mon2]

No schematics, only BV files.

[Dr.d]

Hi mon2....hope you're doing well. I received the PD chip (U22) today. I'll let you know how it goes once I get it installed. Thanks again for all your help.

[parkhayoun]

No schematics, only BV files.

Maybe I can get a boardview file? I will check the power wiring myself. Once again, It would be really helpful to progress my current problem....