Where can you get the parts for this besides a dead board?
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Where can you get the parts for this besides a dead board?
I have no idea.... especialy inductors are big problem, because they are custom made for Abit and I don't know wich value are they... other parts could be bought, maybe HIP6601 would be a little bit problematic too, but I think in USA it should not be a problem.Quote:
Originally Posted by cetoole
did you find e little time to make the shematic diagramm? :)Quote:
Originally Posted by TribesMan
can you make now a shematic diagramm?Quote:
Originally Posted by TribesMan
Ups... I totlay forgot about this... :)
I will make it today.
Ok... lets do it!
First you will need to get a few components. The easiest way to get them is to unsolder them from dead motherboard. What you need is one complete phase of CPU power supply unit on motherboard.
It consist of 2 power mosfets (Q11, Q12 and Q13 are upper mosfets marked as PHB55N03LTA, and Q17, Q18 and Q19 are lower mosfets marked as 05N03LA) you need one of each kind. You also need HIP6601B (Synchronous Rectified Buck MOSFET Driver, U12, U13 and U15 on Abit NF7). Choke is also needed, one of L3, L4 or L5 from NF7 (I don't know value for this one, so it is very good if you have a dead NF7 to collect components from it), everything else you need are a two SMD resistors and two SMD capacitors located around every HIP6601B chip on NF7, and a SMD resistor located at HIP6301 (R168, R167 or R166)
So before start you should have exactly 9 components...
Now the preparations. How you will mount 4th phase onboard is completely up to you, but you must do few things on your NF7 before starting. HIP6301 controller is capable of running 2, 3 or 4 phase system, how many phases will work is dependent from how PWM outputs are used, if you want a 2 phase system you must connect PWM3 and PWM4 outputs to +12V, if you want 3 phase system you only connect PWM4 output to +12V. On NF7 3 phase system is used, so PWM4 output is "disabled" To enable it you must unsolder pin 18 (PWM4 output) from PCB and make 100% sure that it is not connected to anything! ISEN4 (current sesning input pin) 19 is already left open, so you dont need to unsolder it.
Schematics:
http://www2.arnes.si/~mbabic/4phase/schematics.JPG
OK... looks messy :D We need to explain some things... Q1 is upper mosfet, amd Q2 is lower. L is a choke, Risen is a resistor in current sensing feedback line (R168, R167 or R166 from NF7 board value is around 3k[ohm]. Rvcc and Cvcc are conected as low pass filter, so that all high frequency distortions are removed. Value for Cvcc is around 1uF and for Rvcc is 5[ohm], (you can get those from NF7 markings are R152, C142; R153, C143; R156, C169). Ru is a gate resistor for upper mosfet, its value is 3[ohm] and it is marked as R144, R141 or R140 on NF7. Cboot is a Bootstrap capacitor, it values around 330nF, and you can get it from NF7 on locations C132, C128 or C127.
Now to the soldering. You must keep in mind that you need to keep thick marked tracks from schematics as short as possible! Current over those tracks can be as high as 30A so it is crucial that series resistance in those tracks are as low as possible. Also note that Isen and PWM signal lines must be placed as far as possible from all power mosfets and choke. High switching currents in those commponents can cause a lot of interference. Everything else is simple... just solder those components together and mount them on board... where you will place them is totaly up to you, but keep all power lines as short as possible.
That's all for now... When I will have some free time I will make a step by step guide... with pictures and everything...
ok, thanks for the description, i will make the mod next week and then i post the results :devil:Quote:
Originally Posted by TribesMan
Maybe I will try this in next week.. I want to refresh my mods on board,
so, maybe I should have a ocassion to do that :D
Of course, there's one problem - components.. I don't have a other NF-7
TribesMan, should you ask Abit enginners (via e-mail or something)
about these component's values (for example, values of inductors)?
MAY i suggest something ?
You could try soldering a small copper radiator to each of the mosfets
Very nice work :slobber:
:slobber: at the PCI/AGP lock
I think I'll call abit tommorrow and see if they'll sell me a few dead boards. If I can I think I might make a few on pc board and give them to users ;)
Ask them about component's values, please ;)
What do you specifically want to know tonic?
Quote:
Originally Posted by bh2k
Choke's valuesQuote:
Originally Posted by TribesMan
Hey!
It is nice to see that you are interested in doing this mod. :D
About value of specific components. I don't belive that Abit would be willing to give out infos about that... and even if you get infos ther is one problem left... it is almost impossible to buy chokes designed for currents that big... Usualy you can buy chokes for currents below 1A... but this one must be capable of doaing at least 20A...
this is planned... but at the moment I don't have apropriate heatsinks... and I am also very afraid of heatsinks making short circuit... tou must know that "tab" of mosfet is connected to the middle leg of MOSFET... and "tab" of each MOSFET is on different voltage so it is very dangerouse! Making shortcircuit over those two heatskinks would instantly kill the motherboard!Quote:
MAY i suggest something ?
You could try soldering a small copper radiator to each of the mosfets
Don't say hop, until you jump over hurdle :DQuote:
Originally Posted by TribesMan
It's a new type of mod, only you tested this.. do you remember, what
happened, when a some of persons tried to find methods to mod vtt on
NF-7(S)? Yes, they did a lot of tests and found these methods, but they also
sacrificed a some of their motheroards..
Yup, it makes logic.. but is better to try ask Abit's engineers ;)Quote:
Originally Posted by TribesMan
Then insulate these componentsQuote:
Originally Posted by TribesMan
Must be the most modded NF7, not to mention motherboard out there! :up: You really know your sh1t! Truly extreme. Wished this was done on some of the new boards though :)
I'm sure adding it to newer boards isn't that hard, just needs a little research.
I have question ;]
Can I add capatitors under the socket (like TribesMan) from capatitors in socket in death mobo without doing 4 phase? Only capatitors... ;]
Sorry for my English ;)
yes, as long as they are the right ones.
I've got a cooked infinity...
Ok, thanks ;)
I will try solder this... but first I have to solder mosfets... on my NF7 all "power factory" ;) goes down... :( I resoldered all of HIP6601 MOSFET driver chip byt my mobo still dead... and maybe resoldering mosfets turn mobo to live...
It can be easier, but i have one old solder tool... :D
Sorry for English... ;)
BTW. Capatitors like this under the socket have ~4.5uF. All capatitors with that size on NF7 are the same.
sorry for :) English
A relatively close choke can be fabricated by using a similar sized ferrite torroid (the closer size wise the better) and winding the same sized magnet wire around it in the same manner (same number of turns in the same direction) as the stock choke. There is nothing magic about winding a choke. I haven't done hardware for a long time but this is how we used to modify tuners to liberate subscription broadcast TV. We used to buy the ferrites at the local TV parts store.
Hope it helps!
Enjoy!
There are tons of diferent ferrite cores... The size is not the most important parameter. It is relative persistance of material wich counts the most... And it can range from 1 to few thousand... So same sized ferite wont do the magic...
I tried winding chokes for BX6 motherboard... and after that it never worked again...