Killed my 1700+ T-Bred B trying to unlock!

[HaVoC]

I wasn't satisfied with the 12.5 max multiplier on my T-bred "B" core. I have an Epox 8RDA+ and apparently this NForce2 mobo only unlocks to the maximum spec'd multiplier which is 12.5 on my chip. Since my Crucial PC2100 can't do 166 Mhz (keeping it at 150), my quest for 2+ GHz remained unfulfilled.

So, I tried to unlock it by cutting the 5th L3 bridge. (since that is what will trick the mobo to giving me 13.0 and higher mults). I used a utility knife razor blade and carefully scored between the two bridge dots. Unfortunately, when I put the chip back in and powered up, the computer wouldn't boot! After I calmed down a bit, the next day I went to Fry's and bought a new 2100+ B chip. I put it in and luckily the computer booted once I reset the CMOS. I am able to achieve a decent overclock with this new chip (150 x 12.5 = 2025 Mhz) but it sucks that I am out the $52 bucks for the 1700+ that is dead. I guess I must have scored too deeply. Oh well, I guess it could be worse. Maybe some brave soul will buy the chip for $5 and try to fix it.

Since the Fry's chip is $120 including TX sales tax, I'm going to take it back. I've just ordered a 2100+ B core from NewEgg which will be my replacement CPU. I should have just bought the 2100+ to begin with...but didn't know I would run into the 12.5 multiplier ceiling. Stay tuned for my updated overclocking results later this week.

 

[pillage2001]

I'm interested.

mind sending it to me to see if it's fixable?? I'll pay shipping?
hehe

What's the stepping on that bird?

 

[Soulkeeper]

000oo00oo00 send to me 00oo00ooo

hehehehe it ain't broken

try cutting the last 3 L3 bridges then experimenting with different mult settings on your board
it's good to check the cuts with a multimeter to see if there is sufficient resistance between the dots

if that don't work send it to pillage2001, he beat me to the punch

 

[johncar]

Havoc,
Soulkeeper is right, your 1700 may not be broken, here's why it may not have booted after you cut the 5th L3.

C-C-C-C-C = L3 bridges pattern for default 11X for1700
C-C-C-C-O = L3 bridges pattern for "3X", which is a battery saving Power Now setting for "mobile" CPUs, and which any desktop "chokes on", will not boot...as Soulkeeper himself proved by running tests on all L3 bridge patterns with his 1700 and an A7VKT133.

Do as he says...try other settings...for background and detail on how to get you chip to work go to....
<a href="http://www.beachlink.com/candjac/index.htm">
http://www.beachlink.com/candjac/index.htm</A> link to Workarounds article, there are sections which offer alternatives ways to get your chip to boot.
Or there is a simpler way, just open the middle L3 and the chip should boot at 13X. But don't use a knife, you "could" cut too deep.
Wear away material gradually with something like a jewelers file with a very very fine tip, and inspect often with optical magnification.
John C.

Ps:- The Table in Tbred article will tell you what to expect for various settings, with notes on what Soulkeeper got on all the Mobile and undocumented "Reserved" settings....all thanks to Soulkeeper... and Floopyb who just yesterday repeated Soulkeeper's tests and got exactly the same results.

 

[KF]

HaVoC:
I really don't think you cut too deep. The line that is there is hair thin and it would be difficult to make it short to anything. Besides that, shorting it would only set the multiplie low, the same as if it was closed. The code that you set by opening just that one bridge is illegal, and won't boot. You have to cut at least one more. I cut 4 and 5 which gives 15x.

Cutting it doesn't take much. I barely scratched the surface about three times with the tip of an Exacto knife sharpened to a fine point. (looking through a magnifying glass). It doesn't look like much of a scratch. That was enough to get a high resistance ( >20K ohms).

Soulkeeper: I tried your trick on my ABIT KT7, and got 20x.

 

[HaVoC]

Well thanks for the information guys! Obviously you have much more experience with this T-bred "B" unlocking than I. I am going to try cutting the last three bridges...so need to cut two more.

Only problem is that I don't want to keep installing and removing my HSF (fear it will weaken the socket A lugs and make the SLK-800 hold-down spring loose) I'll also see if I can check the chip with a multimeter here at work.

 

[boggsie]

Isn't it possible to take a +5v or +9v battery and use the voltage across the bridges to melt or burn the bridge material?

I've been hearing more and more about this method and it has worked for me the couple of times that I tried it.

Just thought that it would be worth a shot, since the utility knife method is a bit unnerving.

 

[human2k]

Fry's let you return overclocked CPU's?

 

[HaVoC]

Fry's let you return overclocked CPU's?

I believe it's a don't-ask don't-tell policy. The CPU must be working and there must be no physical damage. I'm overclocking to 2 Ghz, true...but it's at default voltage with a very good CPU cooler. I've also checked Prime 95 for 8 hours and it ran clean. If you overclock it too much and burn it out, then they will definitely not take it back. BTW, it's one of those amber PCB T-bred "B"s so it's an earlier one and it doesn't seem to be a great overclocker. That's just as well...I might even back it down another multiplier bin just to be conservative.

 

[ChampionAtTufshop]

Originally posted by: Soulkeeper
000oo00oo00 send to me 00oo00ooo

hehehehe it ain't broken

try cutting the last 3 L3 bridges then experimenting with different mult settings on your board
it's good to check the cuts with a multimeter to see if there is sufficient resistance between the dots

if that don't work send it to pillage2001, he beat me to the punch

hey im gonna attempt to unlock the higher mults for 1700+ and my bridge config is CCCCC for L1 and the one below (L3 i believe) is also CCCCC
...which bridges did you cut to get your higher mults on your a7v (i know there was a thread....but i cant find it lol)

 

[Soulkeeper]

I just cut the last L3 bridges
then you can choose any available mult with the motherboard

 

[touchmyichi]

Frys lets u return anything. I fried 2 processors so far and I got full refunds on both. Here's what you do-

Customer (you)- "This cpu didn't work right. I put on the fan and everything. I thought there was something odd about the core before I installed. There was a little brown mark. I've been building PC's for __ years, this has never happened before."

Most of the time saying it didn't work works too. Try to clean off anything leftover from unlocking the multiplier.

 

[ChampionAtTufshop]

Originally posted by: Soulkeeper
I just cut the last L3 bridges
then you can choose any available mult with the motherboard

last L3 bridges...as in more than one....which ones exactly heh?
thx

 

[HaVoC]

Frys lets u return anything. I fried 2 processors so far and I got full refunds on both. Here's what you do-

Yikes...well I'm not returning a dead proc. I'm returning a physically untouched 2100+ b-core. I haven't messed with or unlocked any mult on that core. Since it's 2100+ default, the 13 x and higher mults are available to me in the BIOS so I can overclock without cutting L3s.

Anyhow, UPDATE: I took everyone's suggestions and bought a multi-meter at Rat Shack. The last L3 registered over 40K ohms but the first 4 were closed 0 ohms. That encouraged me so I cleaned up some gunk off the chip with WD-40 then rubbing alcohol. Then I took my trusty razor blade and very lightly scored a few times on the 3rd and 4th L3 bridges. After that I confirmed that the resistance was 20-40K ohms. (didn't register closed with the continuity buzzer either)

Here's a extreme-closeup PIC: L3 Bridges on 1700+ Butchered by Havoc

I was tempted to crack open my PC to test it but I'm gonna wait until my 2100+ comes in (unfortunately it's already too late to cancel the Newegg order and I'd rather keep a 2100+ since it will probably overclock higher than this 1700+. If I can get the 1700+ to work I'll just sell it.

 

[ChampionAtTufshop]

so i take it we cut the last 3 bridges?
hmmmmmm....no mult meter...but i guess i have to bust out my utility knife

or maybe a battery lol
anyone try blowing bridges?
(ive read about it and all...never actually done it myself haha)

 

[Soulkeeper]

yes the last 3 L3 bridges

i've tryed blowing bridges with a 9v battery (and other voltages)
i find that using an exacto knife is much cleaner and works better

 

[HaVoC]

i've tryed blowing bridges with a 9v battery (and other voltages)

Now that I know how to cut these bridges, I agree that a sharp knife (X-Acto will work best) or razor blade is the easiest. Use plenty of lighting and work with a steady hand. I'd be more worried about using the relatively high voltages on a 1.6V processor...what if you touch the wrong bridge and fry the processor? Anyway it's pretty easy to check your work with a multimeter.

 

[johncar]

But how do you "control depth of cut" with knives?? Cut too deep and chips don't work. "Wear away" gradually as we wrote above is safest IMHO.;-)
John C.

 

[HaVoC]

There is a risk of cutting too deep. I guess I will find out on Friday when my other processor comes in if my 1700+ works or not. However, I don't think many people have access to a very fine file like you talk about. The bridge gaps is about 1-2 mm so you need a fine-edge instrument. BTW, have you heard of anyone else cutting too deep and killing their chip? I'd hate to be the first case.

 

[johncar]

Originally posted by: HaVoC
I don't think many people have access to a very fine file like you talk about. The bridge gaps is about 1-2 mm so you need a fine-edge instrument. BTW, have you heard of anyone else cutting too deep and killing their chip? I'd hate to be the first case.

Get a used diamond coated rotary burr from your dentist, the finest pointed one he uses for cleaning very small diameter cavities, we did. The point is 1/3 or less of the length of bridge. Then epoxy into a tube...voila', the perfect tool for careful/gradual wear away use like a pencil or surgical instrument with fingers motion only, heel of hand fixed on workplane.

Yes, we've seen posts of CPUs not working after being modded with "knives".
John C.

 

[rogue1979]

Originally posted by: Soulkeeper
I just cut the last L3 bridges
then you can choose any available mult with the motherboard

Wow, your old KT133 let's you pick a 20X multiplier? Right now my bios goes 5-12.5X, with a setting for 13X and above. So if I cut the last three bridges will my bios give me access to 5-20X? Is that bridge number 3, 4 and 5? My fsb is maxed at about 160ish, so depending on my cpu overclock I will need access to 12.5, 13, 13.5, possibly 14. Or will this mod just give my 13X and up?

According to the interactive t-bred chart at ocinside.de, cutting the last 3 bridges will hard mod the cpu to 17X.

 

[ChampionAtTufshop]

Originally posted by: HaVoC
There is a risk of cutting too deep. I guess I will find out on Friday when my other processor comes in if my 1700+ works or not. However, I don't think many people have access to a very fine file like you talk about. The bridge gaps is about 1-2 mm so you need a fine-edge instrument. BTW, have you heard of anyone else cutting too deep and killing their chip? I'd hate to be the first case.

im going to attempt it this weekend or something too lol
maybe tmr
i dont have a mult meter......gonna hafta go buy what i see lol

 

[HaVoC]

i dont have a mult meter......gonna hafta go buy what i see lol

Radio Shack had a deal on an analog multimeter. Radio Shack MM for $12.00 That should be plenty for your purposes. My local Rat Shack was sold out so I went to the next step up compact digital one for $20. I might return it and get the cheap one. I've spent way too much on the overclocking stuff. :Q

EDIT: the cheap one may even be better than the $20 one in that it takes "AA" batteries instead of expensive button cell watch batteries and the test leads look to be long and sharp. You will need that to make solid contact with the gold bridge "dots"

 

[ChampionAtTufshop]

yah...but apparently it wasnt needed heh
i just did it by looking at it
and feeling (yes feeling lol)

i did it wiht a flexible razor blade thing...so it was possible to feel the bumps ...as soon as i got to the bumps for the whole line, i quit and stuck it in and it works

weird thing is, it ALWYAS shows up as an athlon 1400MHz no matter what mult i set it to.....however...in windows via wcpuid its using the correct mult as determined by Soulkeeper

thx alot Soulkeeper!

 

[HaVoC]

weird thing is, it ALWYAS shows up as an athlon 1400MHz no matter what mult i set it to.....however...in windows via wcpuid its using the correct mult as determined by Soulkeeper

That must be a BIOS issue. The motherboard is taking the correct mults, but the BIOS does not display it correctly. (can't read the 5-bit multiplier code?) Try upgrading the BIOS. Otherwise you will just have to ignore it and enjoy your overclocked performance.