Link Search Menu Expand Document

Osborne 1

Osborne One NA 227319

Repair Log


Found loose screw from bracket which attaches between case and logic board. Reinstalled. Replaced three power supply X-caps. None had failed yet, but I’d rather not have to worry about it. Reinstalled power plug door, which I’d forgotten to put in place before I closed up the case last time.

Osborne One Eugene CL 2018/10

CRT is black and white with a cover glass mounted with double-sided tape. Video jumper is missing, which is probably why the prior owner thought the machine was broken. Carrying handle is in nice shape, unlike previous unit. Includes a modem wired to the 9-pin serial port. Keyboard has all the keys! Siemens floppy drives, apparently single density. No double-density add-on. Doesn’t load my double-density floppies, so time to make some single-density ones.

Repair Log


Floppy drives: light cleaning and lubed with machine 3-1 and lithium grease. Power supply: two 0.01uF and one 0.1uF Rifa capacitors no doubt planning to blow at some point, electrolytics look OK but should probably be replaced.

Osborne One OMSI/Ctrl-H 2019/08

Very custom system. Orange plexiglas over CRT. Aftermarket(?) fan installed on rear of case. Clock or timer affixed to front face.

Repair Log


Opened up for the first time, inspected. There are some interesting add-ons, or maybe it’s just the way the thing is built? It appears there are separate video and floppy boards. There’s also some peculiar (re-?)routing of power cables and connectors. And there’s a TON of very tired double-sided tape.

Replaced the two Rifa capacitors on the power supply with X2 film capacitors: Kemet R46KI21004001K 0.01μF and Kemet R46KI3100JBM1M 0.1μF.

CRT was showing no life. I spent a bunch of time jiggling and cleaning and bending the connector to the CRT PCB edge, and twisting the brightness and contrast knobs, and could get flickers of an image. I inspected the solder joints, and wouldn’t you know it, there were several broken on or near the flyback transformer. I retouched a bunch of spots and now it’s rock solid.