Extracting or removing a DIL chip from a socket

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Extracting or removing a DIL chip from a socket

You have to be careful when trying to removing a socketed DIL chip from it’s socket. The socket grips the chip pins/legs tightly. If you don’t use the correct technique, one end will come out easier that the other, with the chip rotating as it comes out, resulting in the last few pins at one end being badly bent.

You may come across IC removal tools advertised as chip (or IC) extractors or pullers. But most of these when used, still have the problem of resulting in bent pins.

The recommended method, if you can get easy access to both ends of the chip, is to ease it gently out from both ends.

You can use a suitable small to medium size slotted flat bladed screwdriver or blunt knife for this. When using either, the object is to get it between the plastic of the socket and the body of the chip. Do not lever against the PCB, as this may result in damage to the PCB tracks.

Do take anti-static precautions before starting. Professionals will want you to use a anti-static wrist strap, mat etc. But for the most part, doing the following is good enough for most chips used in 1980s computers: wear cotton clothing, slightly moisten your fingers and touch an earthed/grounded metal item before touching or handling any chips. Keep doing this regularly, and always if you have got up to walk elsewhere and have returned.

It’s also good practice to earth/ground metal tools before using them on or near chips.

When handling chips, where possible, try to hold them on their case, and try to avoid touching the pins. Both to reduce the chance of static electricity damage and to avoid contamination of the metal pins with your natural oils.

When holding PCBs, hold by the edges and avoid touching components, the contacts of the connectors or the PCB tracks.

Working alternatively from each end, gently lift the chip a bit at a time. Do this until the middle pins are almost completely free. When the chip is nearly out, keep a finger on each end to help prevent the chip from jumping up and rotating (if it does, at least one pin will be bent).

Once out, if any pins are bent, carefully flatten them and carefully bend them back into shape using flat-nose pliers.

When reinserting DIL chips, ensure that there are no bent or broken pins. Check by looking along the chip from both ends, that all the pins are in line and straight. Check the spacing width wise to see if they will line up with the socket. New chips, as supplied by the manufacturer are likely to have their pins splayed apart at an angle rather than being at a right angle from the package.

There are special tools to align and bend the pins to the correct position, or you can do this manually. You want multiple pieces of paper or a magazine, or similar on your work surface (to protect the surface). Hold the chip by its case body at both ends (use both hands). Turn it so that the body is lengthwise and at a right angle (vertical) to the work surface, now press the row of pins (their sides) into the paper/magazine so that the pins bend slightly inwards towards the chip body. Rocking it while applying pressure helps. But don’t go too mad!

Do the same for the other row of pins. Inspect, then compare against the socket. If you bend the pins too much, you will have to use flat-nose pliers to bend the pins back.

When inserting chips, carefully inspect each and every pin, looking for damage and dirt. As well as the alignment.

If pins are dirty or contaminated, clean first with IPA (not the drink!). An eraser designed to remove ink or a PCB eraser block or a glass fibre cleaning pen may be needed if the pins are really bad or have tarnished.

Line the pins up with the socket, then apply even force across the chip body and push it in. They normally require quite a lot of force, so ensure the PCB is on a flat work surface with a wad of paper or a magazine to protect the surface. If a chip needs very little force, it’s likely that the contacts in the socket are bent or damaged. If the socket contacts don’t make good contact, this will cause various difficult to diagnose problems.

Always check each socketed chip to ensure that they are all fully in their sockets. Check each pin to see if any have been bent and are under the chip or missed the socket.

Mark