Osborne One NA 227319

Repair Log

2018/01/05

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

2018/11/09

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

2023/11

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.