Hi Ki:
Thank you for taking time replying my question. I did replace the blue capacitor (2200uF, Philips) on the power supply board. Its positive side bulged out and inner foils were completely burn. On that board the TRIAC for 6.5V was also severely damaged, which resulted in the carbonization of circuit board.
For basis board you mean the board with all the connectors for logic and audio "cards"?
Yesterday I checked the reel motor control board. Although I saw a slight trace of black on the flat cable, the major components (darlington transistors, diodes, other transistors) seem to be O.K. Three 0.47uF capacitors also test O.K.
One thing puzzles me is why the tape counter remain at 0.00.00, no matter how the tape guide roller spin?
When I pressed those programmable keys there were display "H.XX.XX" "L.XX.XX" "L.XX.XX" "L.XX.XX"; (calibration parameters?).
Press play and record together did not invoke record function. The red LED above Record never light up.
In master control section the tape speed control and PLL capstan work as expected. But CCIR/NAB, MONO/STEREO has no effect. On periphery control board no LED light up.
I did not have time to go to service manual in detail yet. Browing through sections I had an impression that I have to re-do the mechanical alignment again first. I disassembled both reel motors, both tension boards with rollers, pinch roller assembly, capstan rotor/shaft, tape lifter to reduce weight during transport. (Fit in a large suitcase as a luggage, still overweight a little.) I have not work with a reel machine with tension control on both sides before. Now I realize it is all a different story.
On 2/25 of service manual there is a section for error message: EE E1,2,3 for data error in one of the EPROMs. Could it be a checksum routine? I will disconnect the VU meter plug to see whether the corresponding error code appears.
Later.
Best Regards,
Y.-J. Wu