totally new to Osborne and I picked up an Osborne 1 and an Osborne Vixen locally this weekend. Seller was the grandson clearing out storage and knew nothing about these machines but he did have them booting and computing. He stated that the internal monitor on the 1 was not working which I confirmed.
I've scanned the service manual and focused on the video connector from the daughter board (Screen Pac?) to the CRT. Pin 4 is supposed to be 12 VDC, but is only reading 1.2 VDC.
As you can see, the external monitor (which gets power from the motherboard connection) is working fine. So I assume the issue is with the Screen Pac or related area.
Main PCB voltages seem fine. I inspected the connector solder points and the usual bad solder joints and reflowed a couple.
Is the rainbow ribbon cable oriented properly and on the correct pin header? this is how it was when I disassembled.
Anything obvious to check from this point? Thank you!!
I've scanned the service manual and focused on the video connector from the daughter board (Screen Pac?) to the CRT. Pin 4 is supposed to be 12 VDC, but is only reading 1.2 VDC.
As you can see, the external monitor (which gets power from the motherboard connection) is working fine. So I assume the issue is with the Screen Pac or related area.
Main PCB voltages seem fine. I inspected the connector solder points and the usual bad solder joints and reflowed a couple.
Is the rainbow ribbon cable oriented properly and on the correct pin header? this is how it was when I disassembled.
Anything obvious to check from this point? Thank you!!