Service Forum

[validname]

Hello all,


I have some questions regarding the problems im having with my Thinkpad T61P.

My TP is SVP locked, so i had constructed the simple-ic serial interface to read out the eeprom (P24S08), soldered the wires onto the SDA / SCL / GND, ive used 2 220ohm resistors on the sda and scl wire.

I Booted up the laptop to the bios untill the SVP prompt. After that i connected GND SDA and SCL to the circuit, and tried to readout the eeprom using the reader software.

I was unable to read out the eeprom, so i figured the problem might be the resistors who were dampening the signal to much. I desoldered them and reconnected the wires again.

Tried to boot up, and then the problems started. Boot up. blank screen, heatfan starts spinning but stops after 3 seconds. and then the following

Error beeps 1 - 3 - 3 - 1

I've tried a couple of things
-connected AC power, same result.
-Disconnected other FRU's, same result.


Does this mean my Bios is corrupted?
Or is my EEprom fried?
Is it the power source?
I have an arduino clone-board laying around, is this a "safer" way to read out the eeprom using (Bus pirate like software?) instead of using the rs232 connection?
Can i still read out the Eeprom with the TP in this state?

I hope someone can point out what i did wrong although i thought i was very secure , any help is welcome, im dieing to fire up this beast again!

Thanks in advance,

VN

[victor]

[validname]

I connected it as following, and i removed the resistors.

Rs232 SDA Wire > resistor > Pin SDA
Rs232 SCL Wire > resistor > Pin SCL

Hope this clears some things up. Looking forward hearing your reply

[victor]

If the resistors were removed, then the zeners could not regulate the serial port ouuputs and about +/- 8..12V was supplied to the motherboard. Your best chance is that ony some fuse was fried and not the southbridge's SMbus ports.

Change also the RAM, after this experience the internal 2402/2401 eeproms used by SPD could be damaged too.
_________________
Victor Voinea
ALLservice HQ, Romania.

[validname]

update: i removed both RAM modules and tried booting up the system. Same result.

I think i have to dismantle the whole board and check if the fuses are still intact.

Ill keep you updated!

]edit: i forgot to mention that i didnt reconnect the RS232 cable after i removed the resistors from the wires.
So i might have accidently shorted the circuit?(system was off when i removed the connection)
Do those error beeps also occur when the EEPROM is corrupted?

[victor]

No. When eeprom is corrupted the laptop shows some numerical errors on screen.
_________________
Victor Voinea
ALLservice HQ, Romania.

[validname]

i disassembled the system board, and checked all the fuses. But they appear to be intact. Could u tell me the numbers of those mosfets on the board?

FRU 42W7651
http://www.allservice.ro/forum/images/T61-1.jpg
i have this board architecture

[bob]

Check also all low value resistors you may find. Have you replaced the RAM?

Mosfets used are almost all SOIC 8pin

[Topic moved]

[validname]

ha! found the topic again

Update:

I have tried booting up de system using only the CPUFAN + Speakers, still getting errors

@bob im booting it up without any RAM modules.

I will try to identity and find the mosfets you are mentioning, thanks for the information. and i will make a high res photo of my board. That might help aswell

It's kind of weird that after i disconnected all the wires and resoldered them again, the board seems to have failed.. Maybe i overheated some components?

BTw im preparing my arduino clone to readout and make a dump of the eeprom using i2c, will that still be possible when i have those error beeps? Since the tutorial is mentioning that you have to be at the password prompt.

Thanks so far for the replies, will keep you posted

[bob]

The beeps error is due to missing RAM. That is why I asked you if they are damaged but now I see that they are missing completely.

We can offer support for our software and hardware, so if you want help then use R24RF08 and the interfaces supported. They were specially made for in-system read out and for this eeprom.

[validname]

i have checked the RAM modules by exchanging them for others but the problem still persist.

Cooling fan stops after spinup, blank screen, 4 series of beeps.

[validname]

update: the GPU and CPU seem to warm up when those 1 3 3 1 beeps occur.

@victor: where can i find those IC's you mentioned?

[validname]

bump, victor could u please instruct me where to find those components you are mentioning?