I have a problem on a YBA CD2 alpha player. The laser diod and the YBA blue LED don't light up. Trying to initialize a new CD, the pick up moves correctly to the center of the disc to the position switch. Then the lens moves up and down to search the CD but the laser does not light up.
This happened after I disconnected and reconnected the mechanism (pick-up + spindle motor + sled motor + switches) from the main board.
The pick-up is only two years old and had been replaced and adjusted by YBA. I swapped the whole mechanism with a spare one got from a TEAC PD-365 but it didn't change anything.
As far as I know, YBA never published any service manual, so I've got the one of the CEC 780-880CD which is built on the same base : a SF90 (with 2 6 pin connectors) Sanyo pick-up and a Sanyo mainboard.
According to the service manual, the laser diod is controlled by the Sanyo LC6554H microprocessor. When the pin 43 is low, the laser emits the beam. In addition of the player state, two conditions must be met : the tray must be closed and the pick-up position switch must be closed. As there is no tray on this player, YBA shorted the tray switch so as it seems always closed.
I checked that both signals came properly from the mechanism to the LC6554H on pins 18 and 19. I checked also all the components on the laser control circuit from pin 43 to the pick-up connector and the laser power supply circuit. The only problem I found is that the pin 43 is always high (+5V) even in initialization time.
Did anyone experience such kind of problem ? Might be something wrong with the LC6554H ?
Thank you for your help.
This happened after I disconnected and reconnected the mechanism (pick-up + spindle motor + sled motor + switches) from the main board.
The pick-up is only two years old and had been replaced and adjusted by YBA. I swapped the whole mechanism with a spare one got from a TEAC PD-365 but it didn't change anything.
As far as I know, YBA never published any service manual, so I've got the one of the CEC 780-880CD which is built on the same base : a SF90 (with 2 6 pin connectors) Sanyo pick-up and a Sanyo mainboard.
According to the service manual, the laser diod is controlled by the Sanyo LC6554H microprocessor. When the pin 43 is low, the laser emits the beam. In addition of the player state, two conditions must be met : the tray must be closed and the pick-up position switch must be closed. As there is no tray on this player, YBA shorted the tray switch so as it seems always closed.
I checked that both signals came properly from the mechanism to the LC6554H on pins 18 and 19. I checked also all the components on the laser control circuit from pin 43 to the pick-up connector and the laser power supply circuit. The only problem I found is that the pin 43 is always high (+5V) even in initialization time.
Did anyone experience such kind of problem ? Might be something wrong with the LC6554H ?
Thank you for your help.