Recent content by franklyn

... if the Pinout is the same?

... the VDR opperate at the half of 314 Volt max see the schematics and the are 0,25W and 0,4W ones and it feeds the Triac. https://en.wikipedia.org/wiki/Varistor

Check all the diodes on the small add-on board.

TR1 is a Triac http://www.frankshospitalworkshop.com/electronics/data_sheets/triac/T0805.pdf DB1 is a bridge rectifier maybe 600V/20A. Look for the correct form factor but the old one is good maybe. You can test it, there are only four diodes in it. It’s no problem with a multimeter.

Thanks

It works but my Quadra 650 Mainboard has some problems to run at 40Mhz. The Quadra boots up fine but the video output is corrupted, and the computer then freezes.

I’ve been tinkering a bit and am attempting to build a clip-on adapter for my Quadra 650 motherboard to overclock it to up to 40 MHz. I had tried this once before using homemade contact springs, but it didn't work due to contact issues with the SG-615 oscillator. I really don't want to solder...

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 ...