Here we deal with the many faults you are likely to encounter when repairing boomboxes of all types.
Boomboxes, Radio Cassettes or Ghettoblasters, whatever you want to call them were a big thing throughout the 70's to the early 90's. Most people had one in some guise or another, be it a basic one or a huge 4 speaker, battery gobbling monster from Sharp.
Collecting Boomboxes can be a very rewarding hobby and need not cost you the earth. For me the enjoyment is aquiring a radio i remember when i was young, or one i have repaired during my days as a tv/audio repairman in Manchester. There are hundreds to choose from ranging from cheapie brands such as Saisho, Matsui, Ingersoll, Alba, Goodmans etc to the better known brands such as Panasonic, Sony, Sharp, Toshiba, Hitachi etc.
So where do you start? well, it is a matter of choice which one you pick. Generally the better known brands are more collectable and probably will be worth more in days to come and they can be had for a reasonable outlay.
So you have taken the plunge and bought one. It is sitting on your bench at home and you are pondering what you should do.
First and foremost dont plug in just yet. Check for possible damage during delivery (if applicable), give it a shake to make sure nothing is rattling around inside. You should then check the Mains voltage at the rear is set for 240v ac. I know it seems obvious but many were designed for the USA which uses 110v and there is a chance the Radio may have been an import or even that the tapping plate could have shifted during transit. A blown mains transformer usually points to a write-off.
Open the radio, there are usually 6 to 10 screws to remove which are deep down in the casing which requires a long pozi drive screwdriver (usually PZ2). Some are usually hidden under the battery compartment lid or cleverly hidden on the front of the radio. A quick word of warning here. Some radios open with the front coming off. be especially careful here as the internal wires can be very short going to the loudspeakers and forcing them could cause you a whole lot of unecessary work.
Its fair to say that most radios will work to a point and you may be so lucky as to have one thats trouble free.
The usual things that go wrong are the cassette deck, switching, volume controls, antennas, dry joints etc.

cassette deck faults usually turn out to be mechanical rather than electronic. Close attention should be paid to the belts driving the Capstan and also the rubber idler wheels. Cassette heads are usually worn at this age but should function ok after a good clean. Clean the heads, pinch roller, capstan and rubber idler wheels using isopropyl alcohol and a cotton bud. DO NOT SMOKE NEAR ISOPROPYL ALCOHOL.
Other problems affecting the cassette deck are the 'tape in' leaf switches and the record/playback switch (mounted on the pcb). these can suffer from tarnish/dirt over the years and a good squirt with a quality switch cleaner here should suffice. Remember to operate the record/playback switch after squirting to help clean the contacts in the switch.

switching as mentioned previously can cause problems. the function switch and band switch may also need a squirt of switch cleaner too. The same goes with the tone/volume controls which if dirty, can sound 'scratchy' when adjusting the volume.

Antennas notably the rod antenna at the rear has a nasty habit of being missing or snapped in half. They are a weak point but you can easily obtain them from Maplin or CPC in Preston.

Dry joints. These are common around hot or stressed components. pay attention to the volume control pins, record/playback switch pins, pcb mounted mains transformer pins, the figure eight connector (if pcb mounted) is notorious and finally the audio output i.c. pins.

if you need help and advice in repairing your boombox please feel free to drop me an email to stating your fault symptoms and i will try to help.