Recent content by franklyn

Switch-mode power supplies consist of a primary circuit (mains voltage) and a secondary circuit (5V and other low voltages). If the mains fuse blows, first check whether the rectifier (diodes) has a short circuit; next, check whether the high-voltage main electrolytic capacitor has a short...

... so there are SWIM1 = 344SO061-A SWIM2 = ? SWIM3 = 343SO137-A

I have a SWIM chip from a IIcx motherboard and an oxidized one from a PPC7100 motherboard. How many different versions are there? Are they interchangeable, or is the pinout—for example—different? I’m asking because I would like to have a Macintosh II with an 020 CPU for upgrade purposes...

I installed the Q650 motherboard into the cx case because of the three NuBus slots, and the Q700 motherboard is back in its original case. ... I still need to do a bit of rasp and hone on the back panel, and then paint it.

What kind of thread does the screw have to mount the HDD bracket ...?

Reset Switch is a 3D Print part send to me from the seller who sold me the case. LED part is made from a 4mm Plexiglass sheet ...

The circuit diagram is correct. Is there a list of replacement SMD transistors (EU types) for the original types? They must, of course, have the same pinout. I destroyed the Q9 while trying to control it manually and replaced it with a BC557 for testing purposes.There's an internal switch in...

The Q9 transistor is ok. I must test more, I will see the Eject signal comes from Pin9 of the Floppy connector ...

Inside the bottom of the IIcx case, there is a chrome-like coating—and sure enough, when you test it, it conducts electricity for shielding purposes. I'm a bit nervous about placing the Q700 motherboard in there without a piece of cardboard in between ...?

The schematic isn't quite accurate, because on my floppy drive, it isn't transistor Q7 that controls the eject motor, but rather Q9...

Yes, I currently have a Q650 motherboard in my Q700 case. Reinstalling the original Q700 board makes sense, as the IIcx case features a third NuBus slot—which would provide a better fit in terms of slot configuration.

Thanks

The hardest part was not removing the inner metal shielding plate to work on it.

... thanks but I can not find it.

Looking for the schematics from a Sony 2MB Floppy from a Macintosh IIcx ... The Floppy works fine but the ejector motor isn't running. It's not the gearbox or its plastic gears in it.