General Repair Instructions

Basic rules

If you want your repair job be successful, you must follow several basic rules:

• get as much information as possible. Use search engines, visit forums, ask other people, open some other cheap model and learn there, first
• there is lot of knowledge behind each device. You need basic knowledge from mechanics, electronics only when you want to do advanced service. For basic service, like belt replacement or cleanup, your brain and hands are sufficient. Do not mess with things that you don’t understand
• prepare your work-space before you start work. Small devices use very small parts. Be prepared that you will search for them. Clean table + clean floor = higher probability that you find them
• make documentation of every step you do. Before you disconnect something, make photo of original state. Drawing is even more useful because you draw it exactly how you see it.
• use only quality tools. Low quality screwdriver = high risk of damaging the screws, for example
• basic tools that you will need: philips-style screwdriver, precision tweezers, small pocket knife, organizer box, IPA, cotton wool, lamp with magnifying glass, soldering station, multimeter. Other tools, according situation
• Never use brute force to open anything!

Where to start?

First, you need to remove the back cover. Usually it is very simple task, just remove several screws holding the back cover and that’s it. After you remove the back cover, be careful not to loose any small parts, like switches, sliders, springs, etc. Some cheap plastic players do not have screws. Some sport-version waterproof players are difficult to disassemble.

My cassette player has belt, how to replace it?

• 1. you must buy it
• 2. you must locate it in your player
• 3. You must remove old belt and clean belt path
• 4. You must install new belt – route it correctly

More info here

Oil or not?

My answer may surprise you but it is not always necessary. Plastic parts have self-lubrication properties. You should oil capstans but original oil is mostly still good. It is also not easy to remove capstan without damaging small plastic washer that holds it. So be careful and better think it over, first. I use high-grade watch oil. Grease moving parts – only those that come into contact with metal.

What else to adjust and check?

It is absolutely necessary to adjust speed. As parameters of electronic components controlling speed changes over time, speed changes. It usually slows down. Also, adjust speed after you replace the belt. Thickness of new belt is different than original and it has effect to speed, too.

Do not forget to check quality of pinch rollers. These are second mist common sources of issues. If rubber is too hard or too soft, or they’re cracked, you need to replace them, too.

Besides speed adjustment, there are other adjustments, like output dolby level or azimuth. These should be performed by experienced technicians but they’re not absolutely necessary.