HELP! MSI GT72 power issues

I'm happy to go on a short finding mission but I'm going to need detailed instruction from you guys! I know nothing about this stuff, unfortunately (though I'm learning through this process!).

Actually when my friend and I fitted the new power jack, we did scratch the motherboard (the green PCB, not any traces), which we were aware could cause a short if touched by the solder. However, we removed any solder that was near the scratch and tested it with a multimeter after and there was no short. I just don't understand why a power jack short would only occur when gaming. Surely the problem would occur on the desktop too, or the laptop wouldn't turn on at all, if it was the power jack?

 

Might be a good starting point it might not be a MSI laptop being shown however you do the same process for any laptop.

However wouldn't it be better to send it in to someone whom specializes in this field?

Personally i would.

 

Thanks, I'll take a look when i next get a chance.

I would love to send it to someone that knows what they're doing; however, i don't know anyone that can help me out. I'm also not currently in a position to spend much on this laptop. Repair shops near me charge too much for motherboard repair unfortunately. If i can fix it myself then i'll continue to have a gaming laptop, otherwise it will have to remain faulty, which seems a same. Unless there are any experts on here that could help?

 

troubleshoot 101: 1st thing to do is to remove the dedicated GPU. Don't worry the fan will be at max speed, this is normal EC Panic mode as the mxm card is not present.
Then try to bench hard and see if the laptop still shorts out. If it does, it's most probably the CPU power rail. If not, it's definitely a dying MOSFET on the MXM card.

 

I removed the card last week and the laptop didn't short at all, though i didn't try any benchmarking. I'll try that shortly.

I suspected the MOSFETs on the MXM card. However, i tested the card for a short and there wasn't one (see post quoted below). Could it be that the MOSFET only shorts when under load?

 

Absolutely. The Maxwell cards are know to have very weak power rails. For instance, 970m have only 2 power mosfets and 980m, 3. For the Pascal generation, MSI 1060 mxm have 6 and 1070, 10 IIRC... So no surprise if I tell you that maxwell cards are dropping like flies after a few years.

 

I've just tried switching from discrete to integrated graphics (didn't physically remove the card, as I didn't have the time) and running the heaven benchmark. It's been running for just over an hour so far, and hasn't crashed.

It really sounds like the GPU MOSFETs are the problem. Given that there's no way to confirm this without taking them out. At this point, should I just go ahead and try replacing them?

If so, can anyone point me towards the right part from a UK based retailer please (or somewhere that will deliver here without extortionate delivery)?

The only thing that's throwing me off is that resetting the EC allowed me to game for 2+ hours the other day, immediately after the laptop crashed 3-4 times in a row less than 5 mins into a game. How would this have happened if it's a MOSFET problem (or any hardware problem)?

 

It can happen if the MOSFET is weak and the power demand is too high. You can add a few more MOSFET on the power rail, as there are reserved space on the PCB for additional ones.
But if you benched without any crash in IGFX mode only, it means that the dGPU is working badly now.
Be aware that you can change dGPU on the MSI GT72, up to 1070 gtx... 1060 / 1070 gtx may be a good option if the 970m is dead.

 

Is this the correct part?

The MOSFETs on my card have the following written on them:

87350D
TI553
ZCRT E3

Does anyone have any experience with mouser shipping by the way? The default shipping shows as £12 which includes customs fees (even though there aren't any for low value goods such as these). There are alternate options, which don't show a price but show "bill recipient". If there are no customs fees, is this free delivery?

I'd love to upgrade to a 1060/70 but I'm not able to spend much on this laptop. Looks like they cost a fair bit

 

If you are in the EU, try TME, or Farnell, or RS.
Mouser and Digikey offer free shipping above 40/50€ orders, bellow that, you pay shipping but thats the final price, no surprise VAT or chargers on top.