custm42435
Member
I purchased an sx-64 back in feb and all has worked fine until last month. The Sx-64 boots fine and screen can be seen through external connector in the rear when hooked to my 1702 monitor but internal monitor has stopped working. When switched off i can hear a slight high voltage crackle like the tube discharging although no image is ever visable on screen as well as no heater glow from CRT neck. Here is what i have found out so far from my checks.
No heater Voltage on CRT (i can hook an external power supply to the heater line on the neck pcb board and get a slight image when feeding about 6.5 volts to it that is not the correct size of the screen or the size that it is supposed to be displaying and colors aren't showing up when using this method)
Missing 28V on the 28V line (showing up as approx 6.5 or 12 or so Volts and not the 28V that it is supposed to be. i dont have it in front of me at the moment to get exact but definitely less than half of the 28v on that line) I am assuming this is the main reason im not getting rest as this seems to be the only missing voltage.
Been trying to read the schematics to figure out where the 28V is created and why it isn't being created but havent had any luck so far. Maybe someone that can read Schematics better than i can will be able to help. Schematics are located here for it. (pg 20 and 21 for monitor)
https://c64.berrydejager.com/wp-content/uploads/2013/06/SX-64_Portable_Computer_Schematics.pdf
I know i could completely bypass fixing the CRT and install an LCD but i would like to try to keep original if possible. Any Help Appreciated.
No heater Voltage on CRT (i can hook an external power supply to the heater line on the neck pcb board and get a slight image when feeding about 6.5 volts to it that is not the correct size of the screen or the size that it is supposed to be displaying and colors aren't showing up when using this method)
Missing 28V on the 28V line (showing up as approx 6.5 or 12 or so Volts and not the 28V that it is supposed to be. i dont have it in front of me at the moment to get exact but definitely less than half of the 28v on that line) I am assuming this is the main reason im not getting rest as this seems to be the only missing voltage.
Been trying to read the schematics to figure out where the 28V is created and why it isn't being created but havent had any luck so far. Maybe someone that can read Schematics better than i can will be able to help. Schematics are located here for it. (pg 20 and 21 for monitor)
https://c64.berrydejager.com/wp-content/uploads/2013/06/SX-64_Portable_Computer_Schematics.pdf
I know i could completely bypass fixing the CRT and install an LCD but i would like to try to keep original if possible. Any Help Appreciated.