USB PD needed to repair a MSI Claw - Page 1
Forum section: electronics / repair

author: dbuergi
author_rank: Newbie
timestamp: February 21, 2025, 08:30:49 am
content: Hi all,i got a non working MSI Claw and found a blown tantal cap. After replacing it the board showed 5V and 0,3A input. Thermal cam shows that the pd controller chip on U6 is getting hot and nothing else warms up on the board and since it is close to the replaced cap i guess i have to change it.My problem is that i don`t find the Texas Instruments TPS65993 anywhere (besides some aliexpress dealers) or a datasheet. TI offers a TPS65994 but without a comparison i don`t know if i can use it.One other question, could a reball of the chip help?

author: bigendian
author_rank: Regular Contributor
timestamp: February 21, 2025, 10:41:11 am
content: If i am not wrong, the TPS65994 is qfn, not bga, so in any case you cannot use it. And reballing if the chip is damaged is of no useful.If it's very hot, i would check carefully all components around there, trying to draw a schematic of that area, maybe something is drawing current. Are the usb connectors clean of any dirty ?

author: dbuergi
author_rank: Newbie
timestamp: February 21, 2025, 11:00:22 am
content: I found both chips in a bga version at AliExpress and ordere them for trying.I also added a better pic of the area but all components look fine and testing didnt show anything strange.

author: dbuergi
author_rank: Newbie
timestamp: February 21, 2025, 10:49:45 pm
content: I found out that i made a mistake. The chip in PU10 is also getting hot. Its named DFAFZB. Is this a converter?So two hot chips and they truth somwhere hidden between them.

author: thm_w
author_rank: Super Contributor
timestamp: February 22, 2025, 12:26:11 am
content: Did you verify all ceramic caps are not shorted?Are the ICs in question shorted on any pins?FETs checked for shorts?The aliexpress listing is claiming TPS65993 is a TPM IC, so nothing to do with power switching. If the IC you see is not BGA and connected to the USB power in, then its not the right chip and you are reading something wrong.Photos are not good enough to see any detail.

author: dbuergi
author_rank: Newbie
timestamp: February 22, 2025, 11:41:11 am
content: Quote from: thm_w on February 22, 2025, 12:26:11 amThank you for your help. I added a better pic. I testet all caps and resitors and get values from 1,8v, 3,3v and 5v.Only strange one is marked red on my pic. Resistance to ground under 1 ohm and showing 0v when board is powered.I hope this helps somehow.Would be easier with a datasheet of the TPS65993 but i cannot find one and also TI couldn't help. I contacted them by mail. Maybe ITS a problem that i'm a private person.

author: bigendian
author_rank: Regular Contributor
timestamp: February 23, 2025, 08:13:43 am
content: so i would try to draw a small hand made schematic of where the tracks of that TPS65993 are going.It is available on aliexpress, but is not clear what it is. Not sure to trust it's a PMIC, it should have coils and bigger caps all around. So should be important to understand what it does.If it is connected to VBUS of usb, so it's likely a parent of TPS65994AD, but hard to say if it's compatible.Btw, if from a raw schematic you figure out nothing at "valley" side of him is drawing current, and it ias "very" hot (i touch it briefly by hand to understand if it's hot or very hot (faulty) ),at least it is available and hot air replacement should not be impossible.

author: dbuergi
author_rank: Newbie
timestamp: February 23, 2025, 11:28:15 am
content: Hi,i was able to make a comparison and i cannot change the chips. Too many differences. But close to the chip is a EEPROM and configuration should be stored in it. I will try to read it later but this could mean i can use any other TPS65993 i find. I also got a list with products which use it but i also ordered one from China.The chip gets around 50C with power connected and the other chip on the board is a buck converter getting hot (around 40C). So both chips don`t get very hot. I was also not able to find any shorted pins but found out that my changed tantal cap could be the problem.It has 150uF and the TPS65993 needs one with 47uF. So i pray that this mistake didn`t destroy the PD chip and he was only getting faulty signals.Best case would be that my new cap solves the problem and worst case that the TPS65993 is defective.Sorry if i don't understand anything in first place but i'm not a pro at electronic repairs and translating everything into my mother language is not always easy. :-)

author: bigendian
author_rank: Regular Contributor
timestamp: February 23, 2025, 07:27:52 pm
content: i don't think the bigger cap is the issue. A bigger cap probably just stabilize better the power, but at the same time will be charged with some delay.Did you found TPS65993 datasheet ? What is it doing exactly ?

author: dbuergi
author_rank: Newbie
timestamp: February 24, 2025, 08:56:58 am
content: Quote from: bigendian on February 23, 2025, 07:27:52 pmNo datasheet sorry but strangely ChatGPT can give you all information and also comparen it to the TPS65994. You also get a link for the datasheet at the Texas Instruments homepage but its not working.The chip is a USB PD controller mainly used in laptops and docking stations up to 20V. It's working with mosfets to switch current but the one in trea is working.I took the tantal cap out again and made some meassurements. All caps show 30 ohm, the plus pad of the removed cap shows 30 ohm and with USB power connected i get 5v. All resistors have normal results besides the one i marked in the pic. It only shows 0,4 ohm and in diode mode 0v on both sides. I removed it and it shows 0,4 ohm.Using an external power supply i soldered a wire to the big inductor near the chip and gave some power to the board. At 3v the TPS65993 lighted up and nothing else.But without any schematic of the PD chip i'm not sure how to find the source of the fault.

author: bigendian
author_rank: Regular Contributor
timestamp: February 24, 2025, 09:39:12 am
content: About caps,you can still measure as a resistor, with the ohmmeter. Btw, they charge in time, starting from short, moving to open, measuring ohms don't have any sense, except in the case of a full shortcut.Also, capacitors cannot be tested only by capacitance. It the capacitor is for 16V DC, you should apply i.e. 12V to test it keeps insulation.Generally. for elecrolytics or tantalium, i prefer to change them on any doubt. If it is on a 5V rail, put an 16V, better quite more than the working voltage. Use only brand new caps.

author: thm_w
author_rank: Super Contributor
timestamp: February 24, 2025, 10:34:53 pm
content: ok I think you were right, TPS65993 is a single port version PD controller, mentioned here:https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1061597/tps65994qfnevm-tps65993bfrsl-pd-fw-issueSo you can see how it should be used in the 65994 datasheet, but no pinout as the packages are completely different.

author: dbuergi
author_rank: Newbie
timestamp: February 25, 2025, 08:42:04 am
content: Yes and right now i don't have any idea where to get it. TI couldn't help.Right now i'm waiting for an answer from MSI, Mouser and Digikey. Since there is an EEPROM chip close to the PD65993 there is a small chance that all informations are stored in it and there is no programming needed. So if my chip from Aliexpress is not a fake there is a small chance it works.I don't find any other faults and will continue to check when i installed my replacement tantal cap.