Fan running at max all the time after installing OptiBay

The hard drives sometimes have temperature sensors attached to them. If you left it unplugged or broke it, the fans would run at full speed. Maybe check an ifixit guide for your model to see if there is a plug you disconnected.

This is wrong - but I can see the logical behind the "bad " guess. The left palm rest sensor is placed on the mothercard. It has 3 pin, two on one side and the last on opposite. The one nearest to the hard disk is "left palm" sensor.

It seem to me that all sensor problem on the net, always is about the "left Palm Sensor", named Ts0P. I was one of the owner of the problem, and it took me long time to get into the right conclusion, one wasw the find a good way running an ASD-TEST.

THE BIGGEST PROBLEM IS THAT ON THE NET IS TO MANY "BELIVERS" = poeple guessing without any mention about that's its just a guess they deliver. One thing 4 shore - its no "palm sensor" on the upside - there everybody start looking by logical reason.

Because of good picture of other sensors on "ifixit.com" - i get the information of what to look for, and its a 3 pin piece with 2 pin one one side and one on the opposite. Take a careful look at the sensor they are selling and u get a good info who it look like.

Good luck.

P.S. A cold soldering (if that is the reason as many other computer) it an come-and go-problem. Sometime an "openeing" fixe the problem for some days - but one thing is shore - it will come back. On my computer, in the beginning, the fan went high once a week.On the end it was running hi for 80-90% of the time, somtime always.

I've got this same problem…had a spill on the keyboard of the MacBook Pro (A1226, late 2007), couldn't be helped. All was fine afterwards, at first…then, as the day wore on and the keyboard backlight came on, I saw the lower left keys (SHIFT-FN-CONTROL-OPTION-COMMAND) were not lit as brightly as the rest of the keys--or at all. So I set about to fix it. I disaseembled the MBP, took apart the keyboard and cleaned the several layers of thin plastic that make up that assembly.

 

I reassembled everything--the keyboard was now lit properly, but that's when the fans started running at 6000rpm each, NOT right after the spill as one might expect. And, after installing and running the SMC Fan Control app, I saw that there wasn't an overheating issue.

 

I did the SMC Reset, Zapped The PRAM...it didn't matter.

 

After some effort I was able to run a copy of the AHT CD (even though I had the original install disks for Tiger). My MBP has Mountain Lion installed, and it refused to allow a boot into the Tiger Install CD (which is the OS that shipped with this computer). When I got all that corrected I received error code 4SNS/1/40000000:TsOP -128 000. From what I've read, it's the Palm Rest Sensor.

 

Okay, now this is where my sense of logic kicks in. Previous accounts had held (http://www.henrycipolla.com/blog/2011/05/macbook-pro-fix-4sns140000000-tsop-by-replacing-palm-rest-sensor-fixes-fan-constantly-at-100/) that it was the connector that attaches the keyboard assembly to the logic board. The author of the link says that he accidentally tore off some of the foam rubber that forms the top of that connector, while removing the Kevnar (yellowish) tape…and when he replaced the sensor (by replacing the underneath keyboard ribbon assembly), he found that it fixed the problem.

 

The problem with this diagnosis--and what I can't get my mind around here--is that I ALSO TORE THE TOP OFF THE "PALM REST SENSOR" of my MBP---SIX MONTHS AGO! I was careful to replace it back on the keyboard connector and tape it back down…and I had no problems.

 

I've purchased a new Ribbon Connector for the MBP "just in case"--and while I await its arrival in a couple of days, I was still unconvinced that was the source of the problem. So, I kept looking on the Internet…and found my way here.

 

So, there might be some merit to what 2Lazy says…I only wish he could say it a little better. Meaning absolutely no disrespect, as none of us is perfect…I read and re-read his unpolished response several times…and as I thought he might be on to something (and I obviously also haven't found the answer I'm looking for), I decided to post what I've found on here.

 

I'll examine the sensors as he describes, and when the keyboard ribbon assembly arrives I'll install it, and while I've got the MBP apart I'll take a look at that sensor …and I'll post when I've found on here.

Here's an update on the mysterious 6000 rpm fans with no apparent MacBook Pro overheating, Apple Hardware Test error code 4SNS/1/40000000:TsOP -128 000 .

 

As I wrote above, I had suffered a small keyboard spill, which ultimately led to both cooling fans running high. I was looking for what 2Lazy (above) calls a "left palm sensor," and which he says is not found on the end of the keyboard ribbon cable, like every other piece of information I've read…but he claims it's actually the left thermal sensor, under the left cooling fan. That's what I've deduced, as I couldn't find anything that "has 3 pin, two on one side and the last on opposite."

 

I was a doubter myself, as I had noted before. I had actually damaged the sensor months ago when I upgraded the hard drive. I accidentally pulled some of the black foam material off the connector's top, later sticking it back on with tape. So I couldn't understand how it could have gone bad now after all that time.

 

Sorry to tell you this, pal…but it IS the Palm Rest Left sensor, and it is found on top (apparently) of the keyboard ribbon connector.

 

I know this for several reasons:

1. When I removed the old ribbon cable and replaced it with the one I just got from eBay, the fans stopped running at 6000. They've both been hovering between ~1990-2400 rpm. 
2. I installed two different system monitoring programs to try and get a better handle on this. The first, Tunabelly's Temperature Gauge, suddenly listed a "Palm Rest Left" sensor with a temperature that wasn't there before. Curiously, though, the temps of the other sensors have all gone up a bit from the under-100 degree Fahrenheit they were listed at.
3. I also had installed iStat Pro as a Dashboard Widget. It lists the sensor as the Enclosure Base (keyboard enclosure?), which was also not there before.

​

​So, it looks like the simplest way to tell if it's your Left Palm Sensor (or whatever you want to call it) that's causing the trouble, is just install to these apps and look for those names…if you don't see either of them, it's a sure bet that the sensor is missing or damaged.