How to Fix a Cassette Tape.

*this instructable takes for granted that you can use basic hand tools and have good dexterity with small parts. the only items required are the tapes, a small screwdriver set, a pair of needle nose pliers is helpful, and scotch tape.*

for all those folks still holding on to a cherished but broken cassette tape, here's how to properly fix the common ailments. in this instructable we'll cover transplanting the tape from a busted shell to a good shell, how to get into a welded shell cassette, how to splice a tape, and how to fix squeals.

the lowly cassette.. if you were a kid of the 80's you knew them well. littered around the car's glovebox, piled around a boombox, or crammed in your pocket on your way to school, cassettes were everywhere. it's how an entire generation swapped music or impressed their partner with their ability to create a mix tape.

thanks to the ipod and its huge storage abilities, the mixtape has become a lost art. swapping music went from being a very social activity to something as mundane as checking email. despite the advances in tech, millions of cassettes still survive as do the machines to play them on.

granted the music on many tapes is available in digital form but not all. lots of folks used hidden recorders to make bootleg tapes at concerts. just look at the huge online community that still swaps grateful dead recordings. many of those bootleg recordings were initially made on cassette. there's also mixtapes that were made with a personal touch that a playlist on an ipod can never come near.

enough reminiscing, let's dig in!

 

cassette shells basically come in two types, welded together and screwed together. the screwed together shells will have from 1 to 5 screws holding them together. the welded ones have no screws. both halves are joined using a process called sonic welding which makes repair a little difficult but not impossible.

welded shell tapes must be cracked open. screwed together tapes come apart easily once the screws are removed.

before touching any magnetic tape, wash your hands with dish soap and dry them thoroughly. you dont want to get grease, grime, oil, or dirt on the tape itself.

if your tape has snapped and wound itself up so you have no tape in the access hole, you need to open the case to fix it. if your tape is mangled or broken but both ends are still hanging out of the shell, you can fix that without opening the shell. mangled tape can be straightened out and carefully wound back up by turning the hubs on the cassette. broken tape in which both ends are hanging out of the shell still can be spliced without opening the shell. see the step on splicing tape.

cassettes which are squeaky, binding, wrapped on themselves, or the shell in just in very poor shape, will require disassembly. some DIY articles mention using vegetable oil to cure squeaky tapes and that is 100% wrong. do not do that as it will gum up the works on your tape machine and ruin the tape over time.

on a screwed together shell, you remove the screws and the shell comes apart. best bet is to perform the whole operation without lifting the tape off the table so you don't spill its guts all over the floor. you should be able to remove the top half of the shell while leaving the bottom half and its contents laying on the table.

make sure you use a NON-magnetized screwdriver for this. magnetized tools will cause drops outs in your tape. remember this is magnetic media. do not use magnetized tools for any of this work.

screwed shell tapes make great donor shells. if you have any screwed together cassettes that don't interest you, don't toss them. they are perfect for transplanting the guts from a welded shell cassette that had to be cracked open for repair.

if you are going to be repairing a welded shell cassette, you will need a donor shell to move all the guts into. even when they snap open in a clean fashion, welded shell cassettes never go back together properly no matter how much crazy glue you have. old cassettes are cheap at flea markets. get some screwed together donor shells if you plan on fixing old tapes.

it's destroy stuff in a vise time! (who doesn't like destroy stuff in a vise time?)

there's two well known ways to get into a welded shell tape. one is to use an exacto or other knife to pry your way around the seam, snapping the welds as you go. i have tried this and impaled myself too many times.

my preferred method is the vise. insert cassette into vise as pictured and squeeze till you hear the seams pop. turn the tape 90deg and repeat. this should cause enough breakage for you to be able to carefully pull the tape apart without spilling its contents all over the floor.

this doesn't always work as planned. the tape in the picture turned out to be made of a very brittle plastic and it just exploded its guts all over the floor. yep, safety glasses are a good idea here.

just about all pre-recorded tapes will be in a welded shell.

 

no biggie.

take the fullest spool and get it back into what remains of the shell that is useable as pictured. place finger on edge to keep it from unwinding further and slowly wind the tape back up. slow, tedious, and hard to do at first but once you get the hang of it, it becomes easy.

to explain what's inside a cassette, we'll use the one that came apart peacefully.
pic 1 - inside a cassette with half its shell removed.
pic 2- the slip sheet. this reduces friction between the tape and the shell. these can be clear.
pic 3 - the pressure pad. this provides even contact between the tape and the heads on the machine that read the tape. this is an important part and without it, most cassette players will have poor audio reproduction. there are some high end machines that don't require the pressure pad but about 90% of machines made need it.
pic 4 - the Mu metal shield. it has nothing to do with cows. it's a magnetic shield required by older tape machines.
pic 5 - the rollers. most cassettes have two of these. really cheap cassettes may have just a plastic peg here. these can squeal. the only fix is a miniscule amount of nylon safe lubricant on the metal shaft of the roller. we are talking a very small amount as you don't want any lube getting on the tape.
pic 6 - the tape "pancake".

those little plastic sheets are important. they lower friction between the tape and the sides of the case. they also help keep the tape evenly wound. on very old or cheap cassettes, the slip sheets can be made of inferior material that wears out easily causing tape squeal. replacing old and worn slip sheets cures some squealing issues on cassettes.

in the pic there are two slip sheets from the same cassette. the shiny side faces the shell, the dull side is coated with a dry lubricant and it faces the tape pancake. sometimes these can be easily interchanged from one shell to another. worst case scenario being that you may need to do a little trimming so they fit.

in pic 2 there's a closeup of a little plastic peg the slip sheet has to fit around. notice there's a V cut in the slip sheet. when swapping sheets from one tape to another, keep in mind you may have to do a little trimming to make it work.

some tapes used a clear slip sheet. those make it harder to keep track of which side is up so try to keep them laying in the shell in proper orientation. if you do drop it, there's still hope for figuring out which side is up. note in the 1st pic the dull slip sheet has its indentations facing up. that's the side that's supposed to go against the tape.

a common failure on very old tapes is that it will pop off the hub on fast wind. see pic 1. this is an easy fix. on the ends of the tape you will usually have a leader. the leader is a non magnetic bit of tape and it's what's attached to the hubs. the leader attaches to the hubs using a snap in plastic clincher.

the clincher can be opened by sliding it off the hub. see pic 2 and 3. remove the bit of leader left on it. take the leader from the tape pancake, snip off a small piece so you have fresh plastic to work with. lay the leader in and insert the clincher in end first facing the rest of the leader. see pic 4. pinch shut with needle nose pliers. it should click in.

if all went well, it should look like pic 5.

snapped tape can happen. often times its caused by a poorly functioning machine that ate the tape. a machine that eats tape is malfunctioning. it's likely to be extremely dirty inside or the belts are failing. two thing outside the scope of this instructable but not impossible to fix.

do not keep putting tapes into a machine that eats them!

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a snapped tape can be fixed but keep in mind that you will lose that little bit of music that got mangled.

pull out enough tape from each spool so you can work. 6" is generally enough to work and not have it blow around from your breath. yeah, cassette tape is that light. it's very important that you keep proper orientation of the tape here. you will be applying the splice to the backside of the tape and you need to make sure you do not inadvertently flip the tape. easiest way i have found to do this is use a post it to hold tape in place while working. see pic 2.

snip the ends of the snap tape so you have nice square cuts. lay the post-it down on the table sticky side up. lay one end of the tape down. the side of the tape that touches the play heads (faces outside of the tape) should be what is stuck to the post-it. use tweezers or needle nose pliers to lay the other end of the tape down making sure its lined up, facing the right way, and has a very minimal overlap.

use a piece of trimmed invisible scotch tape to hold splice together. see pic 3. scotch tape should NOT overhang anywhere on the magnetic tape. any overhang will mean that there's adhesive tape waiting to catch on the mechanism and bind things up. see pic 4 and 5.

once done, carefully pull tape up off post-it sheet. pull one half up first, then pull up second half. trying to yank it all at once may ruin splice.

this same process can be used to re-attach a leader to a tape. on very old cassettes, the factory splice that attaches the leader to the magnetic tape can fail. this is common in really old sony tapes from the 70's.

is scotch tape the right stuff?
nope, it is not. in reality you are supposed to use splicing tape. splicing tape was at one time a common item at radioshack and music stores. it is no longer easy to find. it can be ordered from tape specialty places but for the average Joe just wanting to listen to an old tape, the expense far exceeds the attention span. quality scotch magic tape, the kind that disappears when stuck down on something will suffice.

once done with your repairs, put the contents back in. don't forget the slip sheets, metal shield (if tape had one, not all do), pressure pad, and rollers. while reassembling, make sure tape is properly threaded in the case. its easy to munch the tape up while trying to fit the case halves together. see pic 1.