The tray goes several times in and out and then only in one direction without stop (tray motor turns below the belt).
Shorting the Tray end switch for stop changes nothing.
An exact analysis provides the following results:
1) No unwanted interrupt between the switch and the associated connections on the PCB
2)a. Between Tray-In (PIN 19, MCU 80C32 = U100 and R20 = 100K) and GND I observe 0V and 5VDC, if I swich on and off the tray end switch for stop shortly after switch on the mains switch. Thereafter (15 seconds) the voltage value at this place remains at 5VDC, independend of the position of this switch.
2)b. Between Tray-out (PIN 20, MCU 80C32 = U100 and R21 = 100K) and GND
there are always 0V
3) At the resonator is to observe the correct high frequency sine wave (PIN20/21-X1/X2)
4) there was several leaked SMD electrolytics on this PCB. This I have already removed and replaced by new ones. Also, I have thoroughly cleaned the board in those areas.
How can I prove whether the MCU IC (PLCC44 outline = plastic leaded chip carrier; 44 leads) is defective or if other things are still broken ??
Replace the MCU isn't easy, because there isn't a DIL or QFP outline.
How can I exactly check the right working of "RESET" and "EA/Vpp" (pins 10 and 35 - go to PLCC outline on page 4)?
Thank you very much for helping and advices.
In the attachement the associate schematics - here the MCU datasheet:
P80C32EBAA pdf, P80C32EBAA description, P80C32EBAA datasheets, P80C32EBAA view ::: ALLDATASHEET :::
Picture of the PCB you will find at post #24 here:
http://www.diyaudio.com/forums/digital-source/133909-very-strange-fault-cd-player-3.html
Shorting the Tray end switch for stop changes nothing.
An exact analysis provides the following results:
1) No unwanted interrupt between the switch and the associated connections on the PCB
2)a. Between Tray-In (PIN 19, MCU 80C32 = U100 and R20 = 100K) and GND I observe 0V and 5VDC, if I swich on and off the tray end switch for stop shortly after switch on the mains switch. Thereafter (15 seconds) the voltage value at this place remains at 5VDC, independend of the position of this switch.
2)b. Between Tray-out (PIN 20, MCU 80C32 = U100 and R21 = 100K) and GND
there are always 0V
3) At the resonator is to observe the correct high frequency sine wave (PIN20/21-X1/X2)
4) there was several leaked SMD electrolytics on this PCB. This I have already removed and replaced by new ones. Also, I have thoroughly cleaned the board in those areas.
How can I prove whether the MCU IC (PLCC44 outline = plastic leaded chip carrier; 44 leads) is defective or if other things are still broken ??
Replace the MCU isn't easy, because there isn't a DIL or QFP outline.
How can I exactly check the right working of "RESET" and "EA/Vpp" (pins 10 and 35 - go to PLCC outline on page 4)?
Thank you very much for helping and advices.
In the attachement the associate schematics - here the MCU datasheet:
P80C32EBAA pdf, P80C32EBAA description, P80C32EBAA datasheets, P80C32EBAA view ::: ALLDATASHEET :::
Picture of the PCB you will find at post #24 here:
http://www.diyaudio.com/forums/digital-source/133909-very-strange-fault-cd-player-3.html
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