Need help on Ez Trak computer board.

[reabdet21]

I have a 1998 EZ TRAK DX 3 axis. When I turned it on, it indicated a failure to boot and a battery failure.

I opened the computer box and removed the computer board. It is the type that has the timekeeper chip M48T86PC1.

I noticed a cap blown near the bottom of the board connectors, C-29. It looks like a bypass cap. It burned the board but it is still possible to repair the pad and solder in a new cap.

Does anyone know why that cap would blow and any advice for me. I really don't want to spend the money getting a new board I am retired and this is a hobby for me to make a few parts for my son in law's business.

While I am at it, I am going to replace the timekeeper chip. I did not record the bios settings so I am a little lost there also.

The system I have uses a back plane and the computer is on a plug in card. I don't know if that makes any difference.

[reabdet21]

I unsoldered the timekeeper and soldered in a gold plated 24 pin socket. All I have is a weller adjustable iron and solder wick so that was time consuming but got it done without damage to the board.

I also installed a new 10mfd cap for the blown bypass. The sniff test told me that was an old problem and not connected to the current battery failure.

I ordered a Dallas DS12887A replacement from Amazon via 2 day service. That would give me time to get the socket and the board repaired.

The shipment from Amazon actually was delivered the following day and the replacement slipped right into the new socket.

Now the hard part.

I rebooted the mill and got a checksum error. At least this time, it did not include the message battery failed. I did not have a full keyboard with an AT plug so I had to plug the keyboard directly into the output of the board that has a PS2 connector.

With no instructions, I had a difficult time even getting from on screen to another on the BIOS. After struggling for a while with little success, I called EMI to see if they had any idea how to get rid of the checksum error. They were no help at all and he spent most of the time attempting to sell me a new board claiming what I was attempting to do was fix a worn out tire (his analogy).

Finally I got to a page where I could select "ignore errors". I don't know if that has any complications but making that selection allowed the machine to continue the boot process and come on line.

Has anyone gone through this before and how should I have handled the BIOS problem. Is it ok to just ignore the errors?

[jmelson]

I unsoldered the timekeeper and soldered in a gold plated 24 pin socket. All I have is a weller adjustable iron and solder wick so that was time consuming but got it done without damage to the board.


Finally I got to a page where I could select "ignore errors". I don't know if that has any complications but making that selection allowed the machine to continue the boot process and come on line.

Has anyone gone through this before and how should I have handled the BIOS problem. Is it ok to just ignore the errors?

The timekeeper chip ALSO holds all the BIOS settings for the motherboard configuration. So, of course, a new chip will have no proper settings stored into it. By ignoring the error, the BIOS put the default configuration, as best as it could determine, into the chip, and if it booted, you should be OK for another decade, at least.

Jon

[reabdet21]

Thanks, I was a bit worried about ignoring the errors but it does seem to work OK. If I still have the machine in ten years or so, replacing the chip will be a ton easier. Thanks.