Any electronics masters here?

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Mudder

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My niece screwed up her laptop and since I'm her godfather and the only one that is remotely computer savvy, I'm elected to fix it. What she did was set a supervisor password and then her cmos battery went dead. when I replaced the battery it said there was a cmos error (date) and kicked me to the supervisor password screen. Since she forgot the password it locks me out after 3 attempts. So I have to build what is called a Driven serial programmer. I have a schematic that says I need a MAX232A Ic but when I go to the Newark page I get a whole bunch of 232A's and I'm not sure what the difference is http://www.newark.com/jsp/search/browse.jsp?N=500003+1001017&Ntk=gensearch_001&Ntt=max232a&Ntx=
All I'm looking for is a chip that I can plug into a breadboard and do what I have to do.

If some kind soul could help me out I would appreciate it.



Scott
 
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The last time that happened to me I sent the machine into support and the did their magic. If I have to start soldering things I figure I'm in way too deep.
 
Scott if you remove the main battery and the cmos battery, it should reset itself. If not, you may have to short the cmos to clear the capacitor. I would talk to Karl about it though.
 
some where on the internet should be a way of reseting the CMOS according to manufactures instructions, most of the time it is simple, some times it can be a pain, depending on the maker. check on the makers support forums
 
Originally posted by Mudder

My niece screwed up her laptop and since I'm her godfather and the only one that is remotely computer savvy, I'm elected to fix it. What she did was set a supervisor password and then her cmos battery went dead. when I replaced the battery it said there was a cmos error (date) and kicked me to the supervisor password screen.


If some kind soul could help me out I would appreciate it.
Click to expand...

Scott; What Manufacturer and Model is the machine? Do a search either on the internet or the company web site. Some machines can be reset by removed both the main battery and CMOS battery for about 1 hour!

Some can be reset by a jumper inside the laptop. Some can only be reset by factory techs (IBM LENOVO is one and I believe these write the password to EEPROM). It is usually encrypted if this is the case, so you can't just erase the EEPROM.

Next time, write down the passwords and put them in a sealed envelope and put in your lock-box!
 
Originally posted by randyrls

Originally posted by Mudder

My niece screwed up her laptop and since I'm her godfather and the only one that is remotely computer savvy, I'm elected to fix it. What she did was set a supervisor password and then her cmos battery went dead. when I replaced the battery it said there was a cmos error (date) and kicked me to the supervisor password screen.


If some kind soul could help me out I would appreciate it.
Click to expand...

Scott; What Manufacturer and Model is the machine? Do a search either on the internet or the company web site. Some machines can be reset by removed both the main battery and CMOS battery for about 1 hour!

Some can be reset by a jumper inside the laptop. Some can only be reset by factory techs (IBM LENOVO is one and I believe these write the password to EEPROM). It is usually encrypted if this is the case, so you can't just erase the EEPROM.

Next time, write down the passwords and put them in a sealed envelope and put in your lock-box!
Click to expand...

It's a Lenovo that uses the superIO chip. That's why I need to build the programmer so that I can hook it up and dump the data on the chip. I have all the programs that I need and I've done it before on two other machines but this one is a little different and I need the programmer When I get it fixed I will write down the password. Because it's my niece's machine, I never see it until there is problems.
 
The MAX232A is one of many RS232 serial transceiver chips on the market. From the Newark page you linked to, there are only two choices you need to pay attention to. The first one (MAX232ACPE+) and the fourth one (MAX232AEPE+). These two come in hobbyist friendly packaging. The others use surface mount technology - probably not what you want. From the two choices above, <s>the first contains a single unit while the other has two units built in</s> both contain two units. Your project will only need one, but check your schematic to match up pin numbers with the datasheet you can get by following Newarks more info link.

PM me if you need more help.

Edit: Actually newark has the wrong info about the first one, I checked the datasheet. The -CPE and -EPE are the same chip but different temperature ranges. -CPE goes from 0c to +70c while the -EPE goes from -40c to +85c. Unless you will be doing this out in the snow, go for the cheaper -CPE unit. Either one will fit in your breadboard nicely.
 
It's a Lenovo that uses the superIO chip. That's why I need to build the programmer so that I can hook it up and dump the data on the chip. I have all the programs that I need and I've done it before on two other machines but this one is a little different and I need the programmer When I get it fixed I will write down the password. Because it's my niece's machine, I never see it until there is problems.
Click to expand...

Sorry Scott; I'm afraid the only solution is to return the machine to support. We had those same machines at the company where I worked, and we set the passwords on all the machines the same. One was messed up and we had to send the machine to support.
 
Originally posted by Tea Clipper

The MAX232A is one of many RS232 serial transceiver chips on the market. From the Newark page you linked to, there are only two choices you need to pay attention to. The first one (MAX232ACPE+) and the fourth one (MAX232AEPE+). These two come in hobbyist friendly packaging. The others use surface mount technology - probably not what you want. From the two choices above, <s>the first contains a single unit while the other has two units built in</s> both contain two units. Your project will only need one, but check your schematic to match up pin numbers with the datasheet you can get by following Newarks more info link.

PM me if you need more help.

Edit: Actually newark has the wrong info about the first one, I checked the datasheet. The -CPE and -EPE are the same chip but different temperature ranges. -CPE goes from 0c to +70c while the -EPE goes from -40c to +85c. Unless you will be doing this out in the snow, go for the cheaper -CPE unit. Either one will fit in your breadboard nicely.
Click to expand...

Thank you Ron, That was the information I was looking for.
 
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