Panasonic RC-CD500 [Repair]
Some months ago, i got this radiocd from a friend of mine whith cd read problem.
After analyze them, i found that all voltages are right and motor driver was broken, so i order one AN8739SB motor driver to aliexpress ( UtSource seller).
When driver arrives, i found another problem: motor cd lens gear box.
Because cheapest construction of the gear box, it is formed by iron sheet holding the gears, so gears can easily dislodge.
I measure motor current without load (20mA) and i realize that motor in his gearbox drains about 160mA and motor wont move because lack of torque. So i adjust iron sheet to remove backlash (backlash dislodges gears).
Now, motor drains 90mA and moves easily.
Another trouble in this unit is that switchs wont work. Is extremely rare malfunction because switchs are symply mechanical item, but i disassemble one of them i i found oxide blocking the connection. So, I changed all switches.
After all, CD unit works flawlessly.