Microsoft KB Archive/66562

Removing and Installing Integrated Circuit (IC) Chips PSS ID Number: Q66562 Article last modified on 11-13-1990 PSS database name: PSS

MS-DOS

Summary:

The following information discusses how to remove and install integrated circuit (IC) chips.

Chip Handling Precautions
First, make sure the power is turned off before removing or installing any memory module kit or other expansion option. Failure to observe this precaution will usually cause damage to one or more components.

Once properly installed, most integrated circuit chips exhibit a remarkably long life. However, it is quite easy to damage a chip during handling.

The chip’s pins are easy to bend, and great care should be taken to make sure that each pin remains straight and that all are firmly seated in the socket. A single bend or broken pin is sufficient to put the chip out of service. In addition, chips are susceptible to static electricity and may be electrically destroyed simply by improper HANDLING.

Keep the following things in mind before removing or installing chips:


 * 1) Make sure that the power switch is off and the power cable remains plugged in, thereby keeping the system chassis at ground potential.
 * 2) Touch the system chassis before touching a chip to safely discharge any static electricity.
 * 3) Before removing a chip, note the orientation of the notch on the chip. Make sure the notch on the replacement chip is positioned in the same direction.
 * 4) It is best to keep uninstalled chips in their original packaging or protect them from static electricity by pushing the chip pins into a piece of conductive plastic foam or by placing them into a sheet of aluminum foil. As an extra protection, the foam or foil should be grounded to the PC chassis by a short jumper wire.

Removing a Chip
Any chip can best be removed using the correct size chip puller. Sometimes it is difficult or impossible to reach the chip because it is located below the hard drive housing or the power supply, or the tool cannot be applied because another component is too close to one or both sides of the chip.

A small, flat-head screwdriver used like a tiny spatula can also do a satisfactory job of removing chips by carefully pushing it alternatively under the chip’s left and right side with a rocking left-right and up-down motion. If the chip is accessible only from one side, the same method can be applied; however, the flat-head screwdriver should be slowly pushed under the chip as soon and as far as possible so that the left and the right side are lifted out almost simultaneously to avoid a sideward bending of the chip pins.

Installing a Chip
Chips can be installed with a chip installer tool or by hand. If you are planning to use the chip installer tool, follow the directions that came with it. If you have never installed chips, you should read at least C.2 and 3 for information that could save you from destroying a chip accidentally.

Making a Chip Fit Its Socket
New chips often don’t fit into the chip socket because the two rows of pins are too far apart. The gap between the two rows has to be narrowed to fit the chip socket. One way to achieve this is to do the following:


 * 1) Hold the chip with both index fingers and thumbs at its front and end.
 * 2) Turn it on its side so that one row of pins is parallel to the table surface and the pins are pointing away from you.
 * 3) Push the whole row of pins with slow even force simultaneously down and away from you onto the table so that the gap between the two rows becomes a little smaller. Be careful not to push too hard.
 * 4) Now see if the chip can fit into the chip socket. If it can, separate it from the other chips that still don’t fit.
 * 5) If the chip still does not fit. Repeat steps 1 through 4. by alternating the row of pins being pushed inward, until the rows are parallel at the most. They should never have to be pushed closer together than that.

Orienting a Chip in the Right Direction
Once all the chips to be installed will fit, make sure that they are oriented in the correct direction by doing one of the following:


 * 1) Use the notches on previously installed chips as a guide.
 * 2) Match the chip’s notch with the notch in the line that is usually drawn around the chip socket directly on the board.

Chips installed in the wrong direction will not function and will probably be destroyed. Be especially attentive to this when installing an entire bank of new chips on the system board or on a memory-expansion option.

Verify Each Chip Matches Those Already Installed
Note that all chips of the same size look pretty much alike, so if you are about to install chips of uncertain origin, make sure they match those already installed. Installing the wrong chip will not permanently damage the computer, but it will likely destroy the chip itself, and system operation may be unpredictable until the chip is removed.

Inserting a Chip into Its Socket
Once you have followed steps 1, 2, and 3 above, you are ready to insert the chips.


 * 1) Align one row of pins with their side of the socket and partially insert them so that they will definitely be properly aligned with the socket.
 * 2) Sit the other row of pins down on their side of the socket, making sure they are properly aligned and ready to slide all the way into the socket. Sometimes it is necessary to push this unseated side of the chip with both thumbs near its top towards the other already slightly inserted row to narrow the gap between both rows and get the second row aligned and slightly inserted, too.
 * 3) Verify for a last time that both rows are properly aligned, then press the chip slowly and evenly down until it is all the way in. The crunching sound during this procedure is normal. It is best to do the first few chips slowly to develop a routine.

Copyright Microsoft Corporation 1990.