Non persistent voltage leads on MB

[FirebirdTA01]

Hi everyone, I have an unusual request. I have an i7-3940xm in my M17xr4 and it's difficult to keep cool. I have already done the m14x fan mod and I'm using Thermal Grizzly Kryonaut thermal compound... it's just not enough. The CPU is constantly being throttled (my bios settings in a11 unlocked are set to throttle it 85 C) when under load, and it will sometimes see temperatures in the mid to high 90s. The maximum operating temperature is rated at 105C, and I have a thermal shutdown set in bios for 100C, which it hasn't yet reached (but it gets scary close).  Even when throttled, it's still an upgrade and runs better then the stock 3630qm, but I don't wan't it to throttle all of the time. I know I could underclock it, but what's the point of having an upgraded CPU if you're just going to downclock it to similar specs as the original (baring cache, of course). At idle, by the way, it jumps around mid 50s to high 60s.

 

Anyway, to keep it cool, I want to try using a peltier cooler. They're thermoelectric ceramic devices of which one side gets hot and the other gets cold when an electric current goes through them, for those who didn't already know. I figure I can sandwich it between my cpu and the heatsink and try to help keep the cpu's temps a little more reasonable. I have one of a workable size which can withstand temps of up to 135C, and I've done the math with it's specs so that it hopefully knocks 25ish degrees off while at full load and not overheat the peltier doing so. This leads me to my question/request; I need to know if anyone would know a place on the motherboard which supplies voltage when the laptop is running, but not when it's off, whether or not the charger/battery is connected? I have found a few good sources on the MB which can withstand the drain, but they're always hot, even when the laptop is off. I have a multimeter and have been probing, but I don't want to disassemble half the laptop and attempt running it in pieces to verify a good source. If no one knows off hand or has any idea, does anyone know of any schematics or files which exist which contain voltage information of various contacts on the m17x r4 motherboard?

 

I know this is a strange request and most will not be able to assist, but before taking it all the way apart to probe around I thought I would at least ask. I'll make a write-up on how it's done and how well it works if it's successful, as well as a controller circuit if necessary using a teensy 2.0 or something.

Edited August 3, 2018 by FirebirdTA01
An additional detail

[FirebirdTA01]

Nevermind, I found one. I'll update with a link to a write up on this project at a later date.

[naightmehr]

Sounds like a lot of effort with a lot of risk. Personally I bought this heatsink from taobao through yoybuy. The heatsink with the m14x fan mod and liquid metal from thermal grizzly keeps the temps easily below 85 degrees with a 4.5 overclock on all 4 cores.

[FirebirdTA01]

3 hours ago, naightmehr said:

Sounds like a lot of effort with a lot of risk. Personally I bought this heatsink from taobao through yoybuy. The heatsink with the m14x fan mod and liquid metal from thermal grizzly keeps the temps easily below 85 degrees with a 4.5 overclock on all 4 cores.

 

Do you think this heatsink will fit? It says its for the r5, r6  (17r1,r2), but looking at it it appears to be the same physical size and layout, just with 2 more heatpipes. Thanks for all of your help, with this and before.

 

I had originally planned on staying away from the aftermarket heatsinks, as I had found this thread which had some people talking about them being worse than the stock cooler. I don't know exactly which heatsinks they were using, or why they had bad results with them, but it scared me away from them. If you say you maintain a regular overclock with one, however, I'll definitely pick one up.

Edited August 4, 2018 by FirebirdTA01

[naightmehr]

I don't think the heatsink you mentioned will work, the R5 has a slightly different dimention, a 4th pipe won't fit on top. I don't know what the experience is from other users but the heatsink I bought from taobao gave me a 12 degrees drop compared to the stock heatsink (tested with mx-4 thermal paste) after that I applied the thermal grizzly liquid metal which gave another 15 degrees drop.

[FirebirdTA01]

I went ahead and ordered the one you recommended. Hopefully I get as good of performance out of it as you do.