ROM Replacement Hints and Tips.

To remove ROM's safely either buy an IC extractor from a local Radio Shack or other outlet carrying electronics tools (get a big one, these are 42 pin DIL modules) or you can use a small flat bladed screwdriver. Ease the blade between the body of the ROM and the plastic socket and lever the end of the ROM gently up by twisting the blade until the it lifts a few millimetres. Do this at the other end. Repeat this until the ROM lifts out of it's socket.

WARNING! Do not get the blade between the socket and the PCB, and do not insert the blade too far or you may lever against the PCB rather than the socket. Either of these risks damaging the PCB with obvious and possibly expensive consequences.

ROM's are often difficult to fit as new ones have the legs slightly splayed so don't fit easily into the socket. Two ways to do this. First way - insert one side of the ROM into the socket so the legs are partially in their beds and the ROM is at a slight upward angle and the uninserted legs are a few millimetres above the top of the socket. Then, holding the ROM firmly by the two ends (not touching any legs) push against the inserted side slightly bending the inserted legs until the uninserted side legs are in line with their beds. Swivel the ROM down until the uninserted legs drop into their beds then gently press down until they are partially in. With finger and thumb at each end of the ROM press down alternately on each end until the ROM rocks into final position. Do not press down in the middle.

Second way - on a flat metal surface (or baking foil or tinfoil) place the ROM so it is on it's side resting on one set of legs. Grip the ROM firmly between thumb and forefinger at each end and twist (pressing down) until the legs bend in slightly. Ensure that they bend at the natural right angle of the legs, not where the leg narrows. Do this for the other side and repeat until the legs are just at the proper angle to drop into the socket cleanly. Insert into the socket (observing Pin 1 orientation) and press down at each end alternately until the ROM rocks into it's socket.

Note that the legs on a ROM can be splayed outwards or inwards and if fitted incorrectly a leg can fold up under the ROM where it is easy to miss, so check carefully that all the legs are aligned with the socket before pressing home.

Again, if in any doubt - STOP! It's far easier to withdraw and regroup than to try and fix up problems later. Please note that the author is not responsible for any mishaps. E&OE

With grateful acknowledgement to E! for the EX5R photos and information.

© 2004 James Attfield - revision 1.0.2 - 16th September 2004