MSI Prestige 15 ms-16S6 won't power

[Dr.d]

Hello.... I have a MSI Prestige 15 ms-16S6 that won't won't power up. Tried a replacement adapter and same problem. I can't seem to find any mosfets near the usb-c input to test for a short circuit. Also NO current limiting resistors that I can find. Does anyone have any ideas on what to check first on the board? Thank you kindly

[mcplslg123]

Schematic or boardview available?

[Dr.d]

I'm not sure. Been trying to locate. Hoping that someone might have some ideas or seen this one with no power. Thanks

[mon2]

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.

[Dr.d]

Hi Mon2.....okay, I'll get some pictures for you. I did find some board views, but no schematics. Hoping you might know, and can lead me to some or some ideas of where to start on the board. Thank you, and I'll get those pictures for you.

[Dr.d]

Here's those pictures Mon2

[mon2]

My apologies for the late follow up. Office work has been going overtime lately.

The boardview diagrams in my database appear to match your board. How are you powering this logic board? Through a USB Type C power adapter? Would you have a USB type C meter? What voltage and current draw do you see with the USB Type C meter? If you do not have such a meter, it is a good investment and available through Amazon / Aliexpress. Useful for quick checks for the USB type C power adapter.

By default, upon power up, the USB Type C power supply will offer 5 volts. Only after a proper negotiation with the PD (power delivery) controller on this logic board will the voltage and current draw change to something else. That is, the PD controller will request from the adapter, a full list of PD contracts (voltage & current pairs). After this list of PD contracts is received, the logic board will then select the best PD contract to power the board. Often, this will be a 20V contract.

Noting this, it is important to know what is the PD contract being selected or is it the power up default.

Also, are you missing one of the USB C connectors in the lower left of your posted pic? The BV shows that there should be a connector onboard.

[Dr.d]

Thank you so much for getting back with me. I value any help you are able to give. I did get the boardview on XinZhiZao site, but unfortunately it doesn't seem to have the schematics. I do have a USB C meter reader. I'm including a picture of it plugged into the USB-C port. It does seem to thave the 5v, but does not go to 20v when the power is pressed and or at anytime. With that, I'm thinking that either the 5v isn't getting thru to where it needs to go for the contract or handshake. Or something else is going on. I've tried other adapters and the same thing. And Yes...it is missing one of the USB-C ports. It came in like that. I was thinking that it does not need that one to power up. The other one I have to do micro surgery on and resolder back on properly as it was loose. I should be able to just use that one to power up the laptop, once I figure out the handshake/contract issue...correct? Thank you.

[Dr.d]

[Dr.d]

Once again...thank you for all your help. I know you're very busy and have about 1,000 people that are looking for your help here on the forum. When you get a chance...if you could maybe direct me of where I should check next. I think a couple of those IC's by the USB's are ESD static protection for the unit I think. So I'm not sure if its that gone bad or if the power delivery IC you pointed out is not shaking hands or talking to the motherboard (back and forth) to turn on the 20v. I don't think it needs the other USB-c port, but I know you know better than I do for sure. I'm hoping you can help me if possible. Especially with no schematics. Again..thanks alot. Darren

[mon2]

Lol. Give or take a few

You have 0A of current being drawn so there is 'no load' on this VBUS pin of the USB Type C connector. Suggest to google and search for a datasheet for any USB Type C connector (which is a spec so almost any datasheet should match your connector) -> review the location of the VBUS pin. Then proceed to select that pin on the BV drawing and see who lights up in the CAD tool. Continue to trace till you can locate a fuse. Hoping there is one in the path. Often will be with a 'F' prefix. Once it is found, meter in resistance mode -> test the resistance of that fuse to see if it is blown or not. Post the resistance. Summary - there is no current draw so there is a break in the power path from this USB C connector to the main power rail.

[Dr.d]

Got it...thanks mon2! Will pursue that next. Will be back with the results to let you know what I found. Thanks again

[mcplslg123]

Most often usb-c port itself is the issue. i'll suggest to replace the usb-c port with a new one first as you have already mentioned it had some issues.

[Dr.d]

Thank you Mcplslg123....I did go ahead and replaced. I appreciate your suggestion.

[Dr.d]

Hello mon2 .... So, I was able to do some readings. From the good USB-C connector (Conn3) on the Boardview. The Vbus/V+ are pins A4 B9 // A9 B4. Those go off PL10, the other nodes are dead ends (i.e. Caps , ect) that I can determine. The 5v goes thru PL10 to IC U22 (TPS65994). From the other side of PL10, the 5v also goes to the otherside of the board. The BV shows it going to PQ1 Gate. There is 5v on the Source and Drain. From PQ1 Drain it goes to the Drain of PQ4. The Source on PQ4 is .4v and the Gate is 0v. I checked all surrounding components for a short or open and cannot seem to find anything. The mosfets seem good , but not totally sure. I know they aren't shorted . I did note that PQ4 also connects to U22 as well. In addition to some other discrete components. Any ideas on where I should head or do from here? Thank you ahead of time. Darren

[mon2]

What are the full topside markings on the TPS65994?

Is it this device?

TPS65994AD Dual Port USB Type-C® and USB PD Controller with Integrated Source Power Switches Supporting USB4 and Alternate Mode datasheet (Rev. A)

[Dr.d]

Here's the full markings on the IC (U22) TI 04AFFP8 TPS65994 . I think its the same, but no AD at the end. I'm attaching a photo for you of it I just took.

[Dr.d]

[mon2]

3rd line = 'AD'



Use the datasheet from this webpage to study the pins used to drive the external mosfet.

TPS65994AD data sheet, product information and support | TI.com

Interesting thread:

TPS65994AD: System 5V short or leakage to VBUS - Power management forum - Power management - TI E2E support forums

Check if the power rails to this PD controller are present. Measure with care since the logic board is powered. Confirm the LDO rails as showing in their datasheet.

[Dr.d]

Okay...thank you. I'll check them out!