How can I fix ESP on my Discman?

Hello everyone:

I'm looking for some ideas to try and fix my Sony Discman D-F400 / D-F411 / D-F415.

The device works almost perfectly: pick up system, motors, audio amplifier, built-in radio, buttons, volume control… they all work very well.

When playing a CD in normal mode (ESP off) it works perfect.

The problem arises when the “ESP” function is enabled. When a CD is playing and the ESP button is pushed, the CD starts to run faster (which is normal) and the elapsed time on the display stays where it was when the ESP button was pushed. The sound stops playing, but the CD keeps spinning.

It's like the “Pause" button would have been pressed. If you press “Pause", the display blinks and you will hear a “beep" every 2 seconds (this is normal when pausing). If you press “Pause" again, the numbers stop blinking, but the time counter won't continue and the music won't be resumed.

When the ESP is enabled, if you skip the track or fast-forward/backward within the track, the time will move and you would be able to hear the CD pick-up mechanism moving. But as soon as the music should start playing again, it won't. It stays “freezed” where it was last selected.

I've extensively searched on Google with no luck. The most common problem with Discmans is related to the pick up system, but not ESP.

I'm thinking the problem might be something related to the memory that stores the disc data. Because it could not be able to store data, the player can't go on, even when the pickup is retrieving data from the disc (I think) at a faster speed than the normal CD audio rate. No strange noises come from the device when it is “reading” the disc in ESP mode. Since the ESP memory doesn't deliver any data to the player, I think it freezes waiting for some data to come.

Any thoughts / ideas / details needed?

Thank you for reading!