[SOLVED] 'ERROR 0175 : BAD CRC STOP POST TASK' on T30

[singbad]

Hi all,
has anybody seen 'ERROR 0175 : BAD CRC STOP POST TASK.' on a T30? I only found reports of T20/A20 series showing this error.

I've seen 'ERROR 0175' only once when I had to enter the BIOS password but this time no password is asked, it just stops. Is there a way to clear the EEPROM?

I remember the T30 even starts with the EEPROM unsoldered so there should be a way to inhibit the EEPROM being read at POST and then enabling the chip again for writing correct data to it, e.g. by one of the diskette based BIOS tools.

Anybody experienced in this field?

Best regards,
singbad

[Harryc]

Have you tried to flash the BIOS to a previous version, or doesn't the boot process get that far?

[singbad]

Have you tried to flash the BIOS to a previous version, or doesn't the boot process get that far?

I'd be glad if I could boot anything. I could try to boot from diskette, however. To make a boot disk I'll have to wait for a working T30 to arrive. I haven't kept the diskette that I used to flash a BIOS the other day.

[singbad]

I've plugged in a diskette drive with a bootable diskette into the ultrabay but it doesn't attempt to even seek a diskette. No move at all.

When I prepared for re-flashing I saw a broken solder joint at the ATMEL EEPROM. I fixed it and voila: no more CRC error!

I really thought the T30 would start into setup without the EEPROM. This one didn't.

Best regards,
singbad

[SMA]

Broken solder joints at the ATMEL EEPROM does NOT occur naturally.
My bet is, that someone has had a soldering iron in there before you.

[singbad]

Sure, and he did a bad job on it.

Too bad I couldn't try my EEPROM writer

[Thinkpad Lover]

Note to mods and administrators: The following post is not an attempt to discuss how to defeat supervisor passwords (which I have come to learn is a forbidden topic on this Forum). That is not my life's ambition in any case. This is just a general inquiry as I love to learn new things. Just curious about this Bad CRC error 0175 and its cause:

What's the whole purpose of trying to read data from the EEPROM? Doesn't this mean someone was trying to defeat a supervisor password and failed? For example I have an A21m with 'ERROR 0175 : BAD CRC STOP POST TASK' which I'm just selling for parts since I have none of the skills with a soldering iron that you guys have. Nor do I know where all these solder joints are located. I'm just curious about the cause of this error and its repercussions. BTW I bought the A21m off Ebay a couple years back (in my earlier days when I didn't know better and it came with a Floppy disk and the promise that using the Floppy to flash the BIOS would resolve the Bad CRC error. I don't think I ever tried Flashing the BIOS using the floppy they provided but now that I'm a little wiser I realize that probably wouldn't work anyway.

My question is: Even if a person were to re-solder joints by the EEPROM (caused by someone's clumsy, failed attempt to defeat a supervisor password?), and get the laptop to post, isn't it possible that they may still boot up into a supervisor password? Who knows at what stage of reading data from the EEPROM they left off? I don't understand much about how this process works so pardon me.

When someone posts a reply, if you have a moment, could you please explain more about the EEPROM and its function, why it would trigger a CRC error, etc. I have an impression but I would like you experts to explain further. I am your student

Here is a definition I found online:

(Cyclical Redundancy Checking) An error checking technique used to ensure the accuracy of transmitting digital data. The transmitted messages are divided into predetermined lengths which, used as dividends, are divided by a fixed divisor. The remainder of the calculation is appended onto and sent with the message. At the receiving end, the computer recalculates the remainder. If it does not match the transmitted remainder, an error is detected.

Thanks,
Daniel,
the little YP/teacher from NYC.

The Best Teacher is a Lifelong Student

[RealBlackStuff]

A bad CRC can occur if you get any interruption or a brown-out/power-out during a BIOS update.
It can happen through power spikes/drops, accidentally pulling the power cord, a battery going bad.
The CMOS dies.
Using cheap parts that deteriorate after some time.
A non-professional user messing with the insides.
That about sums up most of the possible causes.

Often enough, replacing the CMOS and/or (re)flashing the BIOS can cure such a problem.

[cadillacmike68]

I remember when ROM BIOS chips were these big DIP chips and could not be revised I actually have a few old oned in my chips box). Then we got PROM, EPROM and finally EEPROMs.

Ok here's a question: If the CRC check failure is the result of an interrupted BIOS flash process (ex. power cut), and the BIOS is supposedly needed to get the machine booted, how can one cure this with new attempt to flash a new BIOS to the machine.

Or does a BIOS update boot floppy not need a functioning BIOS?? I don't think that is the case, The machine can't boot with a non-functioning BIOS, at least that's how i grew up.

[RealBlackStuff]

I'll let you in on a little secret: Error 0175 does not originate from the BIOS, hence the TP can still boot...
Also check this out: http://www.hardwareanalysis.com/content/topic/31761/
And most importantly: make sure you have the latest BIOS.

[Majestic]

The T2x series all had a BIOS update to help "prevent" the 0175 post error. I didn't see anything similar for the T30 though.