David Cook
Well-known member
I'm always on the lookout for full 68040 chips to upgrade my LC 475 and Performa 630 series computers. The other day, a bent chip appeared on eBay for $30. It isn't a recent mask, but it is rated for 33 MHz. As the seller described, the chip has quite a few bent pins.
Fortunately, no pins are broken and only a few have bends in multiple directions. Most of the pins were easily straightened gently with tweezers and a headband magnifying visor.
The next step is to align the rows and columns. For that, I use 0.1" female header connectors. They are long strips and have just enough slack to accept randomly offset pins. The high-end 3M strips are part number 929974-01-36-RK. But, you can find much cheaper knock-off connectors.
I insert a row at a time, nudging any pins that don't allow the next row to fit. Because the connector holes are evenly spaced, and because the connector width snugly fits against the next connector row, this tends to align both rows and columns simultaneously. After filling up all the rows, I gently wiggle each connector off and then repeat the process rotated 90 degrees for a tiny bit more improvement.
Although the chip pins are now much straighter, there are still a few imperfections and misalignments. You can use tweezers again or perform a test fit on a computer.
It took about 10 tries to firmly seat the chip in the LC 475 socket. I gently wiggled the chip, pushed down slightly on one side, lifted in back up, and repeated the process pushing on different points and different angles.
Eventually, all of the non-conforming pins reached the socket tolerance. My patience was rewarded with a fully working 68040!
Hope this helps others,
David
Fortunately, no pins are broken and only a few have bends in multiple directions. Most of the pins were easily straightened gently with tweezers and a headband magnifying visor.
The next step is to align the rows and columns. For that, I use 0.1" female header connectors. They are long strips and have just enough slack to accept randomly offset pins. The high-end 3M strips are part number 929974-01-36-RK. But, you can find much cheaper knock-off connectors.
I insert a row at a time, nudging any pins that don't allow the next row to fit. Because the connector holes are evenly spaced, and because the connector width snugly fits against the next connector row, this tends to align both rows and columns simultaneously. After filling up all the rows, I gently wiggle each connector off and then repeat the process rotated 90 degrees for a tiny bit more improvement.
Although the chip pins are now much straighter, there are still a few imperfections and misalignments. You can use tweezers again or perform a test fit on a computer.
It took about 10 tries to firmly seat the chip in the LC 475 socket. I gently wiggled the chip, pushed down slightly on one side, lifted in back up, and repeated the process pushing on different points and different angles.
Eventually, all of the non-conforming pins reached the socket tolerance. My patience was rewarded with a fully working 68040!
Hope this helps others,
David
