Membrane repair is a little difficult. First you need to find out where goes wrong. Cut off part of the thin iron wire which is a little longer than that of the damaged circuit, cut off a section of scotch tape, put the iron wire clipped with tweezers on the scotch tape, align the tweezers with the circuit, adhere the circuit to the tape and press, and the problem is solved.
Method steps are as follows: 1. Disassemble the keyboard. Note that when you disassemble the keyboard, be sure to make the button surface (that is our operation side) downward, and circuit board upward, otherwise, the conductive plastic on each key may come off consequently, bringing trouble to your repair work. 2. Disassemble the circuit board. There is usually a layer of membrane made of soft plastic on the circuit board, and key flat cables are engraved on the membrane. Preferably use the cotton soaked in alcohol with the concentration of more than 97% (the cotton soaked in medicinal alcohol with the concentration of more than 75% is also ok, because I once used , but it is best to use the former one) to gently scrub the circuit board twice. For the circuit where key failure happens, scrub it more times. 3. Examine the conductive plastic of the keys which don't work, and if a lot of dirt is accumulated on the plastic, scrub it in the same way as the above. Suppose the conductive plastic is damaged, then I advise you to replace the conductive plastic on the not commonly used keys to the damaged part. Although in this way, it can not play all the keyboard functions, but at least it can extend the life of the commonly used keys. 4. Remove dirt in the inside corners of the keyboard with tools of writing brush, tiny brush, etc. and be careful to be gentle.
Membrane keyboard repair method: 1. Rub the discolored place with an eraser, and check if it can energize with an ammeter. If not, swipe that place with a 2B pencil and have another test. Then it may return to normal. 2. Use conductive silver paint. 1. First scrape off the black portion; 2. Then coat with the silver paint in the original line location.
