12v to 5v? fan mod.

[WarriorII]

OK, wifes laptop died.

replaced hdd. -check
put AS5 on cpu cooler - check

fired it up & it overheated :bang head

looked around - fan not spinning. /get hammer

run to electronics store, find correct size fan & bring home. - check

fan will fit to replace stocker. -cool

new fan is 12v- check
old fan is 5v -cr@p

This is on a older (5-7 years old) HP Pavillion N5135

Question- How do I use a 12v fan in a a laptop?

obvious answer = find a 12v source.

my answer= I have no clue where to look. no spec sheets available.

resistor?

leave apart & fire it up & start checking power sources?

Need some advice / direction.

It's Friday the 13th and a full moon is out........ :rolleyes:

TIA

[four4875]

you could find a 12 V source, possibly tap into the battery (almost) directly for like 14 point somethin volts, my concern there would be turning it off, unless you like wasting battery while not even running. lol.

i dont even know if you will be able to find anything over 5 V after the voltage regulators drop it from battery V. i cant think of anything that uses 12, so you might need to mod the fan to run right at lower Vs or just get a 5V fan.

Im not sure, but i think that if you were to take off a bunch of the windings of the motors magnet, it would decrease resistance, increasing current (at 12 V) and power consumption, but at 5 V can get it around normal, same power draw as at 12 Vs but just less voltage. I havnt actually done this, its just me speculating. if i wasnt so lazy i would do some experamenting with an old 80mm i have here and look at current and power draw and such, and compare speeds and current draws.

but i think the easiest thing to do would beto fix old fan (if you can figure whats the problem) and stick it back in, or get a 5V replacement. im suprised you found one that would fit at radioshack, around here they dont have CRAP for fans, a couple P1 heatsinks and like a 60 and 80mm, and thats it.

[WarriorII]

lol, I'm scr3wed. :D

this thing is like... baby sized.

I got a Vantec chipset cooler & it's the right size, but wrong voltage.

:(

Hmm......

thanks for the reply 44.

[eobard]

Got pics? That is a hard one. Maybe if we all saw what you were up against one of us might have a better chance of helping.

[WarriorII]

Exposed area.

[WarriorII]

Molex for mobo from fan.

[WarriorII]

Stock Fan specs. 5v - 2A

[WarriorII]

Replacement Vantec fan.

[WarriorII]

Fan mobo header. black thing to right is HS - fan removed from it to check.

[infinitevalence]

why not just let it run at 5v? that would be much easier than doing any mods

[WarriorII]

I think I'm going about this the wrong way.

Trying to find 12v outta 5v POS. :-/

Skou mentioned I should try ebay for a new fan. :(

It's cheap, but takes time. (for shipping)

:shrug:

[eobard]

I suggest you hit the major fan manufacturer's websites just to see what's out there first. I don't have any scale for the fan you need but a quick check of NMB's web catalogue shows they have three 0.98inch fans that run off 5v, three more that are 1.18inch 5v, and three more that are 1.38inch 5v. That's 25mm, 30mm and 35mm respectively. Main site linky (http://www.nmbtech.com/index_f.html). From there follow the "fan" link near the bottom.

[four4875]

does the vantec even spin at 5Vs? if it even does, id still be scared as hell of overheating. i mean in my lappy with the fan running properly (just a bit of dust inside i found out) my mobile barton 2500 hit 93 degrees C running at stock, so if the fan only ran at less than half of its power, i'd be scared to see how high it got.

edit: and is it apparent how the old one is dead? is it ceased up? or just not spinning? does the fan header have power? if the bearings in the old on were locked up you might be able to pull it apart and lubricate it and possibly sand down the shaft a little so it fits a wee bit looser and spins freely again.

have you tried the fan with a 5 V source to mke sure it doesnt work? i know my lappy doesnt kick on the fan till its too high in my opinion (50s)

im assuming its a lappy that worked fine before you replaced the drive and put on as5 ?

[WarriorII]

Ahhhhhhh....... a good nights sleep & I'm ready now to do this right.

I'm gonna say that the fan was the original problem & by letting
the system overheat, it killed off the hdd.

the vantec will not spin @ 5v. :(

The old fan looks brand new, clean & spins freely. :shrug:

I even oiled it, worked it in good & tried it back on the fan header
on the mobo & got nothing.

-even tried the vantec @ 5v & nothing.

I'm sure the header is getting voltage, but I have yet to check with a DMM.

I'll do that today.

I have one more local electronics store to check for a 5v fan.

then I guess it's time to hit the web sites.

[WarriorII]

http://www.apower.com.tw/p02.htm

Middle of page, 40x40x7

That is the factory replacement I need.

I have no clue on how to get these from that Co.

I suppose I could & try to e-mail them, use a CC for purchase.

[four4875]

you might give ebay a shot for a new cooler for it, then you could use the whole cooler or just rob the fan from it.

[Super Nade]

Trying to find 12v outta 5v POS. :-/

:

Mate, if you are trying a Voltage step down, why don't you use a Voltage regulator for that purpose? Simple, painless and easy.

[four4875]

ehh... step UP. he has 5, needs 12, and enough current to run the fan, while not THAT much still i tihnk a bit much for the easy IC buck inverters where its all done in one package.