Kaypro II: help to repair analogic video card

[Enrico Lazzerini]

Hi all,
I'd like to fix the analog video section of my Kaypro II. I submit that
this is not the PC81-240A motherboard that still works perfectly, but the
analog video section because while the cathode is illuminated, the screen
stays completely dark. I've never competed in repairs such as a TV and I am
not familiar with these circuits and it seems impossible to find the
schematic of the analog video card Toshiba TLC-134-T-V-O -with the NEC chip
μPC1031H2 (there were almost 3 types of those anolig cards: Dotronix,
Elston and Toshiba) . What I realized is that the flyback transformer which
has the following labels: TFB1026 2L24DS has 8 pins plus the high-voltage
cable for the CRT. Of these 8 pins, pins 2 and 3 have electrical
continuity between them like all the remains 1-4-5-6-7-8 have it together.
In addition, the pin 3 is grounded. So I assume that the transistor driving
pulses to pin 2 of the flyback transformer and all other pins are
1-4-5-6-7-8 are powers for the CRT. As I said CRTs lights. I want to know:
1) How do I identify the filaments on the CRT? In this way I could
understand exactly functions of each pins 1-4-5-6-7-8 so following the
wiring on the the bottom of the PCB I could exclude some component to
check.
2) How is usually works an output stage of voltage elevation? I have found
some diodes labeled TT2J that seem small balls. What kind of diodes are?
Unplugging and measuring them with a digital multimeter I read in one
direction 1.2Mohm and 850kohm viceversa. Are these values correct?
3) Any other type of indication (for example, some scheme by which to make
comparisons).

Here the picture of the card that could be useful to identify the
components:
http://elazzerini.interfree.it/Kayvideo/Foto2731.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2732.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2733.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2734.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2735.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2736.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2737.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2738.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2739.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2740.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2741.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2768.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2771.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2772.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2773.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2774.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2775.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2776.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2777.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2778.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2780.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2781.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2782.jpg
http://elazzerini.interfree.it/Kayvideo/Foto2783.jpg

Thanks in advance for any useful suggestion.
Regards
Enrico - Pisa - Italy

[Enrico Lazzerini]

Just to say : I solved. Simply the video analogic card not start without
receive signals input. So after to checked that my kaypro-II motherbord
works fine i connecte it to the video card and all goes fine.
Enrico