Panasonic Stereo System Model No.SA-AK5
Complaint- CD and Cassette Player not working but the Radio was working fine
There were no schematic diagrams for this model. In the rear panel, it was written as made in Singapore under supervision by Matsushita Electric Industrial Co.Ltd Osaka Japan.
After 10 years of service this set was brought to me and after opening the cover I found 10 years of old dust. I used a blower to clean the dirt and the dust off before the repair work was started.
I started to check on the CD compartment first because the CD was not detected (displaying no CD) even after the CD was inside the compartment. I found that the laser lens was dirty and I use an ‘Q-tip’ dampened with 90% isopropyl alcohol to clean the lens. Sometimes you can open the drives slide and be able to see and get access to the lens, but not often. After cleaning the CD player lens, it could read the disc again.
Cleaning The CD Laser Lens
Next, I moved on to check the power supply. I noticed that the power supply was a linear type and not a switch mode power supply. The power supply consists of a big linear transformer (to step down the Ac voltage), three big electrolytic capacitors, one relay, four single diodes (connected as a bridge rectifier), few resistors/capacitors and two IC voltage regulators. This power supply has two outputs- 5 and 14 volts. The main board is powered up by the 5 volt and the 14 volt was for the motors.
The Power Supply Section
Power Supply Board Components
I continued with my troubleshooting and began to check on the cassette player section. I found that the motor in this section have problem (not rotating/turning) because there was voltage supply to the motor and the belt already weaken.
Motor and Belt of the Cassette Assembly
Due to this I directly replaced the motor and the belt and the cassette player came back to life. I bought the same part number for the motor and one word of advice-replace the belt with a smaller one (smaller diameter). The reason for it was because after 10 years of service the elasticity of the belt rubber will expand thus you need to get a smaller one to perfectly fit in. The overall total cost of this repair was only 5 USD.
I would like to bring to your attention that the CD, Stereo and Cassette players are no longer being produced. And the new generation of CD players, DVD Players, MP3 or MP4 PLAYERS are distributed to all homes around the world. But this CD player is a good example of what needs to repair and what is common in the ordinary households. I would like to add another tip on this article.
After installation of motor I found that 80 % of knobs of cassette compartments were broken. I knew that I cannot find such knobs anywhere so I have decided to improvise through using of a not very tick hard wire and epoxy glue. I finally repaired all the knobs.