t42 pin mod

hey im new here.
i got ibm thinkpad t42, i855pm chipset, dothan 1.7(735).
i follow about 3 guides from the internet(they all the same), but with no success.
my pll is CY28346-2.
here what i did.
use spdtl too change to ddr266 and ratio of 3:4.
connect pins 54 55.(with wire).
when i connect it screen is blank.(even with speed fixed slow!)what can it be?
if i disable speed step from bios, it boot, but not loading windows. it just blank again.
tnx again forr your time.

 

Post a picture of your mod and I will see what I can do to help.

 

hey, this is my 2 pins 55 and 54(up left corner, the second and third).
i need to cut 55 leg from motherboard?

 

No picture?:confused

 

its big picture... right click on it and open in new tab

 

There is no picture to click on. You did not include a link to get to the site you have the picture uploaded.

 

oh sorry you right:/
2 pictures now.. one is original and the other is where i stuck the cooper wire..
i tried with screwdriver too same result.
tnx

 

I have traced the the two pins as far as I can. One has a resister and one does not. I would assume that the path with the resister is a 3.3 (high) line, and the other is ground (low). Simply shorting a 3.3v line to ground can be problematic. I would guess the resister is there for current limiting. A volt meter would be of help here for sure. What is the stock FSB? I also need the numbers on the chip. A datasheat would be of huge help. If one pin is 3.3v and the other is ground. You need to isolate one from the other to make both ground or both 3.3v.

 

hmm ok.
i got the same chipset you had on old post. CY28346ZI-2.
this 2 pins represent s0 and s1(54, 55).

the fsb is 100, i want to increase it to 133.

here is link to datasheet(cant upload it too big).
http://pdf1.alldatasheet.com/datasheet-pdf/view/227090/CYPRESS/CY28346ZI-2.html

thanks again!

 

ohh and here is bigger picture..

 

You need a volt meter to confirm what pins are high and what pins are low currently.

 

crap i dont have volt meter:/
maybe i will try this pin mod with other cpu?

 

A direct pin mod (under the CPU) is another option, if the PLL does not respond well or is to difficult to mod.

 

ohh, with guid to follow? the 915 pin mod?

 

Nash, I reckon what your mod has done is to pull both pins 54 and 55 low. giving a 66M (frequency meter to check - I have one [ebay about $20 and upwards]. digital multimeter [voltmeter] about $10 and up to many thous anywhere)

To achieve your aim you need to pull both pins high (is my reading of the data sheet). Ideally you should connect pin 55 to 3.3V through a resistor like the one on pin 54 to the 3.3V line.

In practice the only way you might try to this is to short 54,55 together (as you have done) AND break the track connecting pin 55 to 0V (before anything else connects to it) so that that is o/c (cut 55 from m/b. "i need to cut 55 leg from motherboard?" - yes, that's the way I see it). this might connect pin 55 to 3.3V though the pull-up resistor. But it may not work, then you will be coopered because track-breaking is irreversible, unlike connect with wire. (my reading of pin numbers / logic table may not be right)

Personally I wouldn't try it. Anyway things are too small for clumsy old me.

Dumb_Question (electronics idiot)
1.March.2015

 

tnx alot for your asnwer
now im just waitng for getting pentium m 755.(2.0ghz).
if it will not work with pin mod... i will cut the leg:/
maybe i will get a volt meter like your guys advice me.
i learning computer science... but hardware is more interesting