The 5V and 3.3V hard drive issue (any electronics geeks?)

Hi,

This is regarding putting a 5V drive in a laptop that feeds it 3.3V
toughbooks are often or always like this apparently...

I have read instructions, but I have some electronics questions.

I understand from the instructions that you cut pin44 and can cut pin41 just in case.. and are set to go. (And I understand there are some other options.. bending pins.. some special cable.. setting a jumper on the motherboard near the hard drive, but i'm not asking about those other options really, though they're related).

Can anybody - that can explain some things regarding this? some of these may require an electronics background 'cos they're electronics questions..

Is there any kind of specification, that mentions that removing pin44 from a (44pin/2.5") 5V hard drive is going to make it accept 3.3V ? Or that it'd make it run OK on 3.3V?

Is there anywhere that explains why/how that works?

Does anybody know why pins 41,42 are internally connected in some drives and not others?

Can I use any 5V drive or does it have to be specific ones? If so, where is a list? And if some work and some don't, then why? I've heard that Toshiba have an MK range that works.
(i've seen one is 3.3V in the spec, and i've seen one is 5V in the spec.. but nothing in the spec about both voltages.. but maybe I haven't looked at the spec of the right toshiba mk drives. I'm curious about the 5V ones that can be hacked to make them 3.3V). I know some use a Western digital BEVE.. but one person reported that it worked for him without the hack.

People have mentioned a -need- to cut pin 44 and then with pin41, some cut it just in case. What is it with pin41?

I have read that on some drives pin41 is internally connected to pin42. How do people know that? Where is a specification that says so?

And how is that, or is that related to cutting or not pin41.

And would I ever want to bend pin 41 and 42 to join them externally? and thus in that case, not cut it?

Instructions and info from people that seemed to know stuff, were on leog, which is now down. I'm hoping some people here will understand things regarding this.

 

We have already sort of answered this question in a previous thread you started. I'm going to suggest you try to find someone locally who can help you with this, it really is not very complicated. If you feel that you don't yet understand the hack you probably shouldn't start chopping away at your hard drive.
CAP

 

This was the thread.. you're right
http://forum.notebookreview.com/panasonic/553030-hard-drive-cf-w2.html
you referred me to this thread
http://forum.notebookreview.com/panasonic/265815-problem-after-changing-hdd.html

maybe I should keep it to that original thread.. I forgot it was so on topic.

I do understand how to do the hack.. but there are some questions I have about the hack.

And I don't know any less than a lot of the people that have done the hack.

Many of those those that did it don't have an electronics background and wouldn't know why it works or be able to answer the questions I asked, but are just following instructions As I could. But I am asking those questions.

I am not really questioning what the instructions are.

This is for people with an electronics background that can appreciate the questions.

 

Ok I will give this one a shot here it goes:

You W2 is expecting a hard drive that uses these two voltages logic at +3.3v on pin 41 and the motor at +5V on pin 42. The motherboard sends these volatges to the hard driveon the two seperate pins.

On motherboards that use 5V hard drives there is only one power supply being fed on pins 41 & 42 hence they are usually shorted together either at the hard drive or at the motherboard header.

So if you tried to plug in a +5V hard drive into the W2 and it has the pins 41&42 shorted together then you will be effectively shorting out two power supplies on the motherboard which may release some magic smoke or at least trip some kind of protection circuit if your luck.

So the point of clipping pin 41 is so that the above does not happen you will essentially cut off the 3.3V and the +5V motor voltage will control both the motor and the logic. You clip the pin by using a small set of wire cutters or grabbing the pin with needle nose pliers and bend it back and forth until it breaks off preferably flush with the plastic so there is no way for it to make contact.

Clear as mud?

 

thanks.. I almost understand it now. i've progressed my understanding a lot in light of your explanation!

would it ever be connected internally at both motherboard end and hard drive end or would that be an electronic mess shorting it?

If pins 41 and 42 are connected internally at the hard drive end only, then when you clip pin41, it prevents 3.3V going to logic. And it'd still get 5V to logic and motor. I can see that'd make sense to me.

If the connection between pins 41 and 42 is done at the motherboard end only, then when you clip pin41(logic) of the 5V hard drive, So 5V goes down pin 42(Motor) alone. How is anything going down pin41(logic) on the hard drive?

And how can any bridging be done at the motherboard end expecting a dual vote hard drive if a different voltage is put down each of the two pins? It'd mean 5V and 3.3V going down the same connection, which wouldn't work

 

Ah yes you are right I forgot to mention that you must first check pin 41-42 with an ohmmeter at the hard drive. If there is continuity then all you need do is clip pin 41.

if they are not shorted together then this is where you have to cut pin 41 and also make a jumper to connect whats left of pin 41 to pin 42 so the 5V can feed both pins. Some people just bend pin 41 so it touches pin 42 but I don't like this method as it prevents the drive from fully seating in the connector. I have removed the logic board and soldered a small piece of wire at the circuit board contact points.

 

a)where can I see a spec/data sheet of a dual volt drive?



b)what if the internal bridging is/has been done at the motherboard(as in, the possibility that I found problematic).. OK you bridge at the HDD end. But presumably you'd have to "cut" that at the motherboard end somehow? but it's not going to be pins sticking out or wires there.
(I suppose I can assume it isn't.. so maybe 'c' is just a theoretical question, but you mentioned about a situation where bridging was done at the MBRD end)

c)a tricky one.. if you know off hand..
I have seen a 3.3V Hard drive. just said 3.3V on the sticker. Would that be single only? 3.3V on motor and logic? 1.8" drive. (I think it was 50pin IDE - unusual I know - .. and not something I could use in a laptop with a 44pin connector.. I have adaptors but there probably isn't room in a laptop. Was micro IDE(50pin). more pins but smaller than (44-pin)mini ide!). I think adaptors ignore 6 pins. 3 pairs of 2. Leaving 44. Still q of motor and power.. and maybe there are 2.5" 3.3V drives.. so Q of how much voltage on each. I can't find a data sheet for them.. was Toshiba MK6006GAH - sticker just said 3.3V. A detailed spec or a data sheet would answer it.. but I don't know where one would be.. or a standard for such a thing.

 

a) try google the model number of the hard drive that originally came with the W-2 I think Toshiba has it on their website.
b) probably an Ipod hard drive that would be a whole different animal than what we are taliking about. A dual volt hard drive just means that the logic can operate at either 3.3v/5v.

c) A short is a short so it makes no difference if it is at the motherboard or the hard drive. As long as that is the way it designed then no problem.

Key point to remember is the concept of you just want what is at pin 42 at the motherboard to feed both pins 41 and 42 of the hard drive and what's on pin 41 at the motherboard you want it to go nowhere.

Here is a nice pinout sheet that applies to all IDE 2.5" hard drives. on the dual volt HD's you will see the lavel 3.3v/5VL at pin 41

ATA (44) internal pinout and wiring @ pinouts.ru

 

are there any hdd makes/models with a data sheet or specification that states whether they connect 41,42 internally?

If I leave pin41, dangerous, smoke, I won't. If I cut pin41, then considering combinations of whether pins41 and 42 are connected at one end or both or not, what's the worst that could happen? I'm guessing the possibilities are work/doesn't work, and no damage to either laptop's motherboard, or hard drive.

 

I have never seen any data sheets with schematics but I am sure they exist somewhere in some secret lab.

I just checked a random sampling of HD's with an ohmmeter and found that Hitachi, Samsung, Western Digital, Seagate all had 41&42 shorted together. Toshiba, Fujitsu were all isolated. That was my experiance this may not be conclusive to say that all models within a brand will be set the same. Best thing is decide which drive you want to go with then when you get it ohm it out first then figure out what you need to do to make it work. The Samsung Spinpoint 160GB would be a good choice.

 

do you know how many millimeters the drive required is?

I'll get IDE but also, I know SSD is expensive but i'm considering an SSD too. For quietness. Since I have a hearing problem where my hearing is extremely sensitive and I get disturbed by certain tones and volumes.

I do hear a noise from the W2B.. I don't know if it's the current hard drive or something else or both.. It's not an unhealthy noise. The particular tone and volume of the noise doesn't bother my mind/ears terribly.. you don't happen to know or have any ideas what other noise sources there are in the W2B besides the hard drive do you?

Anyhow, you answered the electronics issue.. i'm almost onto getting the drive, just gotta know how many MM. thanks.

 

Ok now everything I said only applies to disk drives not SSD's so you are on your own there Since there is no motor they may work just fine without any mods but you would still need to check if the pins are connected together before plugging it in to a W2. As far as noise goes the W2 should be perfectly quiet except for the hum of the hard drive. Other wise if you hear noise there may be a noisy switching power supply or leaky capacitor. But normally there should be no noise except for the HD. size wise they use a 9.5mm thick drive not sure if there is room for thicker ones.

 

that's brilliant, that answers everything pretty much.. thanks!

 

I just saw an SSD data sheet with pin41 listed as "no connection", so that'd work perfectly. So on pin42 it has not a motor, but uses it for its power source.

Am I correct in thinking that
a)The CF W2's dual vote hdd expecting motherboard will not short pins41,42. ?

b) If a motherboard does,so a case of 5V only It'd make no difference It's just send 5V down pins 41,42 either way. So what is the point of any shorting at the motherboard end?

What's Cutting Pin44 for? does it do nothing on 5V, and on dual vote, it's some completely undocumented way of selecting dual vote?!

 

The IDE ATA6 Standard defines that the IDE controller on a laptop IDE connection shall provide 2 separate power supply voltages on two separate conductors to ensure that clean power arrives at the HDD through the thin conductors of the IDE header cable - 1 5V for the motor at pin 42, and 1 5V for the logic at pin 41. (This is the same reason we STILL have 2 ground wires in every HDD power cable ever made on any power supply, even though they're connected to the same ground)

In an effort to produce a laptop hard drive which draws less power while in standby mode, some manufacturers designed & implemented a subset of the IDE standard which allowed for 3.3V power to the LOGIC portion of the HDD ONLY. If you plug a standard 5V/5V HDD into one of these, it will either detect it as not compatible and shut down the controller, or it will try to work but fail because it is only getting 3.3V when it expects 5v.

By cutting or bending pin 41 flat, you prevent it from making contact with the socket on the MB connection which doesn't have the correct voltage output. You ALSO, in the case of 5V/5V HDDs which have pins 41 & 42 connected internally, prevent that connection from being able to feed 5V back into the 3.3V bus, which is often common power to the PCMCIA or Mini-PCI slots as well.

By bending pin 41 so that it contacts pin 42, you are now ensuring that the logic portion of the HDD (on 5V/5V drives which have NOT been designed with pins 41 & 42 connected internally) now receives the 5V power it needs. You can ALSO clip this lead and trace it out to the connector on the HDD main PCB then solder a small jumper to produce the same connection.

So... first, verify with an ohmmeter whether pins 41 & 42 are connected internally on the HDD. If so, just clip or wiggle/break pin 41.

If not, verify that your HDD is NOT a 3.3V/5V model, then bend pin 41 flat so it contacts pin 42 and verify you have continuity between the two with an ohmmeter. Try it. If it works, then you can do the solder hack if you feel the need to.

mnem
42 is the answer. Again.

 

If pin 41 is in fact not connected on the SSD then it should work without a hitch on the W2

5V is on both pins 41 and 42 on a laptop that is expecting a 5V drive so it makes no difference if the pins are connected on the mb or the hd.

Pin 44 is missing on dual volt drives and usually on the IDE connector the corresponding pin is blocked out, this prevents you from plugging in a 5v drive in a laptop designed for 3.3v. So if this is the case on your connector then you will need to cut pin 44 as well.

Good luck

 

Smeg. I knew I forgot something; thanks for addressing the pin 44 question.

mnem
D'OH!

 

mnemtmth that did largely repeat what has been said..

There has never been any question as to what to do. And most about what happens has been explained.

That wiggle/break idea is very good..

I'm not sure on my ability to solder a jumper on 'cos it'd have to be a very small jumper and can't let the solder drop into the wrong spot. But hopefullyl my hard drive will not need it. I understand that to test it with a multimeter, putting the probes on pins 41,42 should produce 0, and other combinations of pins, 1 or -1 or something.

But as to the questions I asked.

When I asked Am I correct in thinking that :
*The CF W2's dual vote hdd expecting motherboard will not short pins41,42. ?

(I think I was correct in thinking that)

And when I asked
"If a motherboard does,so a case of 5V only It'd make no difference It's just send 5V down pins 41,42 either way. So what is the point of any shorting at the motherboard end?"

I think I was correct in thinking that.
I think there is no point to shorting at the motherboard end in that instance.

(and of course for motherboards sending 3.3V and 5V, those two connections won't be shorted there either and can't be).

So I don't see any advantage in shorting occurring at the motherboard.

I may be wrong somewhere there but I don't know where.

As to pin44. I'm aware that I have to cut it, even mentioned in the first post. And that it's missing on dual vote. I just asked what it's for. My question was to its functionality. I might guess, that it doesn't have any functionality, and its just to try to prevent a 5V drive being plugged in.

Thanks for your replies.

 

Pin 44 doesn't have any purpose, I have seen data sheets where it is labeled "reserved" so no problem cutting it off if your cable has that location blocked.

You have all the information in this and the other threads to answer all the questions you raised. So you should be able to do the mod while understanding why you are doing it i hope. Good luck....

 

I hope you're not suggesting that I don't yet understand what i've read here ;-)

Thanks for your replies

 

Well NO, you DON'T want to do the jumper at the motherboard end; the entire point of this exercise is to PREVENT shorting between the two power supply rails on 3.3V/5V motherboards. Where did you ever get the idea that you should do it at the MB end of the connector?

This is correct; pin 44 is reserved, so more than anything it acts as an index pin.

mnem
Clear as mud now...

 

I am not talking about manually doing something when I wrote.

"The CF W2's dual vote hdd expecting motherboard will not short pins41,42. ?"
(i.e. it wouldn't make sense if it did, so I wrote I think I was correct when I asked ^^. with 5v on one and 3.3v on the other it wouldn't make sense for them to be shorted at the motherboard end - or anywhere else in fact)

and

"If a motherboard does,so a case of 5V only It'd make no difference It's just send 5V down pins 41,42 either way. So what is the point of any shorting at the motherboard end?"

(as to that latter question.. I think that is indeed correct, there is no difference. But it is the way it is for a reason I see tough-to-go mentioned earlier - that there's only one 5V going in. So given that, they have to be shorted, to supply to both, and if they're not then some 5V HDDs , those not shorted there, won't work)

I've got some 2.5-3.5" adaptors(for plugging 5V laptop HDDs into desktops), and I know those only get 2 wires one red wire one black wire going in. one 5V. So shorting's going to / got to occur either at the adaptor or the hdd. Makes sense.

 

ralf...Ok! here is the photo of the modded harddrive. I have four unit of semi rugged notebook series that uses 3.3volts. CF-W2, Cf-T1 and 2 unit of CF-T4. All of these unit has modded regular 2.5 harddrive. Btw, the harddrive on the photo is a regular 5volts tosh.tba and modded to 3.3volts as required by the mentioned pc above.

ohlip

 

thanks ohlip.. that might be useful as an instruction.. but i'm clear on the instructions and judging by what i've written, I think i'm clear in my understanding!

That isn't a very clear picture, but I shall take your word for it that you bent pin41 to pin42, and bent away or clipped pin44! I don't think i'll be doing the pin bending method, because even if I had to, i'd want a tight connection.

Also, if anybody is curious, the dual volt hard drive is a Toshiba MK4025GASL, the BIOS follows that with (pm) which might mean "product manufacturer" since it's officially "not replaceable" - for obvious reasons!

And it does have the 2 voltages written on the sticker! (courtesy of google.com images)
http://fpanapc.fan.coocan.jp/cgi-bin/files/20070925_MK4025GASL.jpg

 

Sorry, man! for a bad picture. I don't have a high resolution cam only cell cam. Pin 44 is as is. No need to bend or do anything. Based on my experienced on bending the pin 41. It still can be put it back the same way as it is when you are carefully enough when bending it to pin 42. little by little i say not instantly same way to put it back to the original position but it must be done only once.

ohlip