I have a Toshiba laptop that doesn’t have a HDD activity LED 
I’ve been looking at various diagrams for SATA and it seems that one of the functions of pin 11 on the drive power connector is an open collector output capable of sinking 300uA maximum for HDD activity so I’m thinking of connecting a pull-up resistor to 3.3V and a MOSFET transistor to drive an LED
I was wondering if anyone here has ever experimented with this ?
Thanks
Isn’t it easier for you to use an app that will have an icon in the tray? 5 Free Hard Disk Activity Indicator Software For Windows
although it doesn’t do much good (LED or tray icon)
because mostly
the disk is in use at boot and until Win finishes its work
disk is in use when doing R/W
the disk can be in use when you are inactive because then updates or defragmentation are performed, AV scans and so on
or every 5 seconds you see an LED flash because something is constantly talking
so in short within every 5 minutes there will be parts when the disk is active so you don’t even have to look
it is very likely that you already have pins for HDD/SSD activity on the MB, but no LED is connected to the case (if you really insist, you might find it on the motherboard)
@Oxy you’re probably right, using an app would be much easier but there is something about LED’s that I love 
I have been thinking of adding an LED for a while and the last time I had my laptop apart when I was cleaning the fans and putting fresh thermal paste I did take the time to check if there was an activity line on the board but without an LED fitted as I had the same thoughts but sadly there is nothing
I’m running Linux Mint and assuming that there wont be as much (if any) activity when the machine is idle
My job is mostly repairing corroded liquid damaged laptop motherboards and I’ll enjoy building something, it’ll make a nice change
I don’t see there being any issues as its a simple enough circuit and as long as I keep the current drawn from the output very low then everything should be fine
Now I just have to find a blindingly bright LED so it will shine through the laptop plastic housing without having to drill a hole 
I had an app that actually uses the scroll lock light (which is otherwise rarely used) and simply uses that light for HDD activity - it probably still exists, so try to find it
I mentioned the apps so that you first see how much use you have (or rather don’t have) of that disk activity
so if it’s really useful for you, then you should throw yourself into making it
I don’t see a problem with drilling a hole
the hole doesn’t have to be big for the LED to fit in
The LED can be behind the hole if there is room, and the hole is 1mm (super small) it just depends on which place you choose for the hole - so that it is visible to you
Thanks for the offer for the app, using the scroll light is a great idea
Sadly my laptop doesn’t have a scroll light but thank you anyway
I’m thinking of adding the extra LED next to the power LED that illuminates the power button in the top right to save making a hole and I kind of like the idea of the power button changing color when the HDD is accessed
The model I have is identical to this one except its an i5 with 16GB ( L50-B-1NX )
The cable for the power button module leads here / MB (near the battery connector - thick pins)
interesting that the PW module has 2 LEDs
what is the second one for? does it change color if the battery is charging or sleep mode, etc ?
or they put two so that it only shines brighter 
you can always use num or caps lock (although it’s not ideal), if I’m not mistaken, I think the app can do that.
The function of keys remains the same, only the light blinking when the disk is…
the numlock (and caps lock) LED’s on this model are badly designed with the LED too low so in normal use its virtually impossible to see them unless you put your head over the key and look straight down
I think the power button is the most visible place to put the led unless I make a hole in the front panel between the power and wifi leds
You won’t even constantly watch disk activity - so it doesn’t matter if you can see it or not
when you need it, put your eye above these keys 
@lovebug if you are going to make your own LED version
don’t forget to let us know when you have successfully burned/destroyed the SATA port 
I have an idea
Get some BT led light bulb (for the house - or any wifi/bt controlled switch (socket) into which you will plug the desired one)
and then you write a script that will send a bluetooth signal
to that bulb and the light in the room turns on or changes color (RGB) depending on the disk activity on your lpt.
I could fill the whole laptop with christmas lights and have it going nuts too
LOL
Take red nail polish and make a dot next to the power led
and pretty much 50% of the time it will show the right condition, so you will have peace of mind !
I found a much simpler program for you without having to bother with scripts
thanks, its a shame that its not compatible with linux mint
Able to use wine?
I just found this - although clearer instructions are lacking
and I don’t know if it should be additionally added to cron so that it starts up together with sys
nor is it necessary to be root
it says for thinkpad but i dont see why it shouldnt work on any laptop
thanks, i’ll check it out
I think it is some additional recognition of the model, etc., so that the config does not have to be edited manually,
BUT all that with LED doesn’t do much good
if it was so super good, then the manufacturer would put it somewhere.
You know - it is as functional as having a LED light whenever you move the mouse
If you suspect that something strange is happening with the disk
then it’s better to open some proc. monitoring and see which processes or services r/w on that disk and if everything is ok, close it and never open it again.
Which is better, LED light to show the disk activity or being made aware of it due to the HDD hardware suddenly turning into a jet motor.
i preferred the old ST506 HDD’s as at least you could hear what they were doing
but then again I had one once that required 12V 11A and 5V 7A
