Service Forum

Mister_Og · Nou Venit Joined: 06 Oct 2009 Posts: 5

Hi, I've built the simple circuit and for zeners I used 1N5231B and not C5V1.
I read the EEPROM and everything was OK, I got a 1KB file.

but when I look at 0x330 I see only 0xFF, here's an image:

Please help me Crying or Very sad

victor · S.F. Boss Joined: 07 Mar 2004 Posts: 2581 Location: Staff

Hi,

Run patcher.exe prior reading, seems like the block is read protected.
>patcher
>r24rf08 dump.bin
_________________
Victor Voinea
ALLservice HQ, Romania.

Mister_Og · Nou Venit Joined: 06 Oct 2009 Posts: 5

Mister_Og · Nou Venit Joined: 06 Oct 2009 Posts: 5

Here is a picture of my wiring, red is SDA, yellow is SCL (ground is connected elsewhere) :

I tried to read the EEPROM with another computer - a Pentium 166, got the same file (same CRC32). Again, with or without patcher

victor · S.F. Boss Joined: 07 Mar 2004 Posts: 2581 Location: Staff

Then I can only assume that this is the real content and somebody tried a wrong program to FF the eeprom. I've seen this a few times.
The laptop has CRC errors of course.

We can fix that but W24RF08 license is required.
_________________
Victor Voinea
ALLservice HQ, Romania.

Mister_Og · Nou Venit Joined: 06 Oct 2009 Posts: 5

Success!!

I found the problem, I will explain soon.

Mister_Og · Nou Venit Joined: 06 Oct 2009 Posts: 5

OK, up untill now I only read the AT24RF08BT when I got to this screen:

Because I wanted to wait until all activity stops.

But now I tried again but this time I read the EEPROM while in the password screen, I.E:

And I saw I got a different CRC32 so I looked at that file and presto! Got the password.

But I was curious so I tried to read the chip twice more to be sure, now I have no doubt - you must do the reading ONLY when you are being asked for a password ( at least on an IBM ThinkPad 600E ).

By the way, the chip is located under the CPU heatsink in 600E, here is a picture:

To read it I had to transfer wires through the battery connector, it's very easy and I'd recommend it for everyone. It looks like this:

Thanks again Victor!

victor · S.F. Boss Joined: 07 Mar 2004 Posts: 2581 Location: Staff

But of course, you have to do that when the laptop is idle, if you do it too soon, the SMBus is busy. Just wait a bit until HDD led is off and the pass prompt is on screen.

Well done and thanks for the nice pics.
_________________
Victor Voinea
ALLservice HQ, Romania.