• Hello MLAers! We've re-enabled auto-approval for accounts. If you are still waiting on account approval, please check this thread for more information.

128/512/plus CRT connector pins

Cinan

6502
Hi all, I am still trying to trace my no video issue on my 512k. Looks to me like the heater circuit on the CRT is not working as there is no glow when the unit has power. I can't find much information re how a CRT works but from what I can piece together the following pins on J2 are of interest

8 - CRT +12v
9 - CRT Cathode

From a learners perspective can I assume that pin 8 here is the heater circuit and pin 9 is driving the signal for the CRT given this originates from J4-Pin 1 video signal ? So should pin 8 be presenting up +12v to the CRT neck to create the heated circuit and therefore the glow in the neck ?

I am getting signal coming out of J4 Pin1 and through the circuit to J2-9 but the screen is blank.
 
Back
Top