NF7-S CPU Thermal Diode Mod, Version 2.0

[Gizmo]

Soldering in paralelel doesn't seem to upset the readings by all that much. However, the method described at overclockers would indeed disable the OTP circuit.

I was thinking we could place a diode like a 1N4001 into the circuit, but I've got to think about it some more.

[IronStone]

@jkesa

nice u linked to this mod from Graystar, he was the guy who gimme the Link to this mod described here by Gizmo ;-) so the circle closes.
Like you said, his mod is not the perfect one for the nf7 coz the OTP must be disabled too. And why loose a feature when u can hold it ?

If someone of you done this mod, pls report your temp differences to the socket temp readings. Ive got 9 till 11° lower temps for the diode then for the socket.

Regards,

IronStone

PS: parallel readings dont run, tried this at first step.

[halcyon]

I know I am digging up a seriously old thread here, but I was wondering what temps people were seeing with this mod on aircooling? I am running a pretty shoddy hs/fan on a Barton 2500 (not mobile) at stock speeds and am seeing under load about 72-73C meanwhile the socket thermistor is measuring 50ishC.. (which makes sense since its not touching the core at all, just hot air under the chip). That sound normal? Just trying to get this setup properly so we can run some phasechange tests...

Thanks!

[Gizmo]

That seems rather high.

Are you reading the temps using MBM? If so, make sure you configure the channel 3 input as a Winbond Diode input, or your temp readings will definitely be wrong.

[halcyon]

Ya I realized that this morning and switched to the diode and everything is peachy now.. at idle its 18C and under load it gets mid 30's. Thanks for such a great mod!!! Oh btw, two questions. 1) What happens if you plug in a cpu that is old and doesn't have a thermal diode? Will it break anything? 2) Is there a quick way to undo this mod, ie can i just cut both the wires and be ok without having to resolder the two pins down to the board?

Thanks!!

[Gizmo]

If you have a CPU that doesn't have a thermal diode, you will get a very cold temp reading, but other than that you should be fine.

No, there is no quick way to undo the mod (I don't believe). This is due to the fact that if you don't solder pin 97 back down, there will be no power to the analog section of the Winbond chip when you snip the wire.

[halcyon]

How about if you just snip the wire going from the attansic chip in the socket to the winbond chip?

[MADXF]

I know this is a bit of thread mining, but great work on this mod gizmo.

Anyway, I have just done this mod (yeah I know slow to catch on), and I'm getting weird readings in mbm.

case - 22 C
cpu - 33 C
diode - 14 C

Before, I used to have a probe placed next to the core and the cpu usualy ended up being about 12-13 over ambient measured by another probe in the radiator intake. And the probe temp was always lower than the socket temp by a few degrees, but this is way too low.
If I place an offset of 10 into mbm it comes out roughly to how it used to be, but surely it should be higher than the old probe setup.

I tried the tool on the first page of this thread, and the offsets were -10, -2, and 0.

How do I know what is an accurate temp?


Cheers.
Paul

[Gizmo]

Yeah, your CPU diode is running below ambient. Unless you've got some kind of chiller on there, something is definitely knackered.

Double-check your wiring and make absolutely certain that you haven't gotten a little wick of solder or a tiny wisp of wire some place where it shouldn't be.

[MADXF]

I did that, checked everything with a magnifying glass, and made sure I hadnt broken the wire when I pushed it under the socket.

The temperature reacts just as it should, jumps about 4deg from idle to load instantly.

[MADXF]

Well, I've just put my PC back together after re doing the mod with some better wire and its reading basically the same still.

My ambient temp is measured by an external thermometer at the radiator intake and is 18.... MBM is reporting the cpu socket at 25, and the diode at 18.

I dont think it should matter, but the CPU I have is a mobile 2500+ @ 2600mhz. Also I'm using D26-mantarays-xt bios with cpc off.

I'm setting MBM to use the winbond 3 diode sensor.

I think I might just have to take a stab at a reasonable offset, from previous temperatures, and leave it at that.

[Gizmo]

Apologies for not responding back previously.

Getting a good calibration on the thermal diode can be a bit of a black art. The diode is capable of being accurate to within about .1C, but you have to calibrate with two current sources that are like 10 µA and 100 µA, apply a correction coefficient, and do some other math to get it right. Unfortunately, the cheap temp sensors that are used on all mobos these days only provide a single current source, which can only give you an approximate reading. You then have to correlate the reading against the actual temp, figure the offset, do that at multiple points, and work out the curve. As nobody does that, either, the temps you get are only approximate to start with, and get worse from there.

Still, for a given mobo, it gives you a good indication of what is going on, and even the error prone readings that we get should be consistent once the offset is known.

Whether it is a mobile or not shouldn't matter. I'm running a 2600+ mobile as well, and the readings are fine. My suspicion is that your CPU diode is a little out of whack, and there is nothing for that but to replace the CPU. Given that it seems to be working fine otherwise, applying an offset is probably the best bet.

[MADXF]

No worries

Thanks heaps for the help.

[masos]

I've a problem. (Who hasn't ?)
I've read about your solution to disable Attansic ATTP1
Rif. : NF7-S CPU Thermal Diode Mod. Version 2.0
I have a KD7A ABIT Motherboard with the same OTPC (ATTP1), a W83697HF Winbond Chip and an AMD XP2500+ CPU (fortunately it works) .
Unfortunately the ATTP1 has broken and now the computer has no boot.
I try to find a new one in a microcomponent shop and a computer shop (seeking it from broken motherboards), but with no success.
Can I also join PIN 97 (lifted) with 61 (not lifted) and PIN 102 (lifted) of Winbond chip with PIN 4 (not lifted) of ATTP1 ??
Help me... as soon as possible also in private (masos@tin.it)
Best regard.

Nik


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[Gizmo]

If your ATTP1 chip is borked, then performing this mod will not magically make mobo work again. If you are unable to get a replacement part, then you should be able to bypass the ATTP1 by soldering a jumper from pin 3 to pin 6 of the ATTP1. This will take PSON_IN and tie it to PSON_OUT.

The ATTP1 works by intercepting the PSU power on signal from the motherboard control logic. If an over-temperature event occurs, the ATTP1 simply signals the PSU to shut down, and that saves the CPU. If the chip is messed up and not allowing this signal to go to the PSU like it should, then you have to bypass it, which is what the instructions I gave above will do.

As for whether you can perform this mod, as described, on your mobo, I doubt it. The main wrinkle will be finding an unused temp sensor channel on the Winbond chip. For my NF7, the unused channel was on pin 102. For your KD7A, it is almost certainly going to be something different. However, if you load up Motherboard Monitor and select the KD7A profile, you can determine (by a little poking around) which channel (if any) on the Winbond chip is unused. From there we can figure out which pin to use.

Does that help?

[masos]

Hi GIZMO,

thanks for your reply.
Tomorrow I'll do what you sayd - a simple jumper between pin 3 & 6 of ATTP1 - ( like drink a water glass ! ). I hope it will work ! I'll make you know something about.
Thanks in advance.

Nik

[masos]

Dear GIZMO,
unfortunately there's something else wrong. When I connect power DC to the mainboard, it starts itself without my permission and nothing is visualized on the monitor. What a pity !
Thanks anyway.

Nik