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Service Forum support board, PC repair, unlocking solutions
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JACB Nou Venit
Joined: 25 Jun 2006 Posts: 2
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Posted: Sun Jun 25, 2006 9:35 am Post subject: SOIC Clip & R40 |
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Hi
I am about to start work trying to unlock my R40 .... In preperation I am doing all the reading I can.
One thing that seems to cause problems is the soldering of the three wires ...... What about using a SOIC Clip?
I beleive that the EEPROM on the R40 (P4 2Ghz later type) is a 8 pin device so I guess that part number 5250 will work?
If I use the clip I will not be able to rebuild the laptop & power it up for the EEPROM dump - Is it possible to get the information from the EEPROM without the laptop being powered and if so how?
I am considering using the following "24RF08 Reader Programmer device"
Thanks in advance |
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steve6386 Interesat
Joined: 28 Mar 2006 Posts: 11
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Posted: Sun Jun 25, 2006 1:53 pm Post subject: |
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Hi,
I used mini grabbers but you do need to be able to power it up. I'm not sure where the chip is on an R40 but just remove the minimum to get to it. So long as you have a power button you are ok. I did it with just the mother board and keyboard (power button was on keyboard) I just needed to time how long it took to get to the password prompt before i took it apart then striped it and had everything ready, powered on waited the x seconds then read it.
Cheers
Steve. |
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rkawakami Interesat
Joined: 16 Apr 2006 Posts: 26 Location: San Jose, CA USA
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Posted: Mon Jun 26, 2006 12:05 am Post subject: Re: SOIC Clip & R40 |
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JACB wrote: | I beleive that the EEPROM on the R40 (P4 2Ghz later type) is a 8 pin device so I guess that part number 5250 will work? |
This looks like it would work by reading all of the package dimensions from the Atmel datasheet and the Pomona datasheet. The only problem, as you stated, is that you would need about 2 inches to install the clip onto the EEPROM and a little room surrounding the part. If you are lucky enough to have the 24RF08 accessable from the bottom of the laptop via one of the removeable panels, then the clip will work.
JACB wrote: | Is it possible to get the information from the EEPROM without the laptop being powered and if so how? |
Well, you can remove the 24RF08 from the motherboard and power it up using the schematic that Victor has supplied (4.5v battery connected directly to the EEPROM with a 100 ohm resistor between the PROT and VCC pins and the WP pin connected to ground).
This appears to be the same type of MAX232 circuit that Victor has provided. The 'chip adapter' board is simply where you would solder on the 24RF08 after you have removed it from the laptop's motherboard. Note however that if you go this route, you would be unsoldering and soldering the part 4 times, thus increasing your chances of damaging the part. It may be possible to use the Pomona clip on a loose part but I don't know if the clip is designed to be used that way. Since the clip is spring-loaded, it might have the tendancy to 'eject' the loose part out of the contact points. |
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victor S.F. Boss
Joined: 07 Mar 2004 Posts: 2581 Location: Staff
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Posted: Mon Jun 26, 2006 11:13 am Post subject: |
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I would never recommend you to unsolder the chip, if you could only attach the 2 wires to SDA and SCL. Is not practical.
Besides, even if you solder them it would be less messy than unsoldering the entire eeprom |
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JACB Nou Venit
Joined: 25 Jun 2006 Posts: 2
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Posted: Tue Jun 27, 2006 8:51 am Post subject: |
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Thanks for all your replies.
It is a shame that I cant supply power to the EEPROM whilst it is still attached to the motherboard via the SOIC connecter for the download/dump. I guess that would be tooooo easy! Just out of interest has anyone tried reading the EEPROM whilst it is attached to the motherboard using this method?
Looks like I will be going the three wire route ..... in the end.
Thanks again. |
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rkawakami Interesat
Joined: 16 Apr 2006 Posts: 26 Location: San Jose, CA USA
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Posted: Tue Jun 27, 2006 9:39 am Post subject: |
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JACB wrote: | Just out of interest has anyone tried reading the EEPROM whilst it is attached to the motherboard using this method? |
If you are talking about trying to power the EEPROM up using an external supply (i.e. the three batteries that would make up a 4.5v source), while keeping the part on the motherboard, then I would say, "I hope not".
1) It would require another wire to be soldered onto the 24RF08 (VCC).
2) Applying power directly to the 24RF08 would probably allow it to be read, however, you may end up damaging other parts in the circuit. You would need a schematic diagram of the laptop in order to determine if it is safe to do. Given that those diagrams probably do not exist outside of IBM/Lenovo's walls (at least in the public domain), you would be taking a chance with your motherboard.
If you follow Victor's directions, you will be using the laptop's normal power circuits to provide the voltage required to make the EEPROM functional. All you are doing with the external interface (be it the zener diodes or the MAX232 circuit) is "tapping into" the signals which will allow you to issue commands to read the contents of the EEPROM. From my standpoint, that is a lot safer to do than applying some external power source and hoping nothing gets damaged.
You really only need to attach two wires directly onto the EEPROM; the SDA and SCL signals. Ground can be connected almost anywhere you see a screw hole in the motherboard. If in doubt, you can use an ohmmeter to determine if the screw hole is connected to the ground pin of the EEPROM. If you are unsure about soldering on the wires directly to the EEPROM, then you can do what I did; trace the circuits away from both the SDA and SCL pins until you find a larger component such as a resistor or capacitor. To do this you will need an ohmmeter and some time. If you do find an alternate connection point which is easier to get at, please post a picture so others can benefit from your hard work.
Check out what I did:
http://www.rkawakami.net/ibm_600x/bios_pass/ |
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