A Macintosh Plus arrived this morning

[PhilC]

And just had time to plug it in and see if it worked as described. It did in fact work as far as getting to the disk icon, so I thought great, powered it off and the RCD tripped turning all the power off in the house.

Guess I best have a look at the power supply then

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[rubber_jonnie]

Oooh, nice. The RCD trip not so much...

I think it's like the Classic in that there is a separate logic board (Check for a battery!!) and analogue board that is the PSU and video, including high voltage.

My Classic smelled like a fishmongers, so I'd go check the caps on the PSU section of the analogue board first. The bulk capacitors seem to be OK, but worth a check, as are the (At least in mine) RIFA caps.

Good luck, looking forward to seeing it all apart and at some point running.

[stephen_usher]

ICD trip is usually the RIFAs in the PSU area of the analogue board. Well known issue.

[PhilC]

ICD trip is usually the RIFAs in the PSU area of the analogue board. Well known issue.

Yeah my money was going to be in there being a Rifa in there causing trouble somewhere.

[PhilC]

@rubber_jonnie the battery compartment is actually on the back of the case and is pretty clean which makes a nice change.

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Typical that it needs a type of keyboard totally different than the LC-II but there are a few adaptor around I can make, one uses an arduino mini which I have loads off.

[stephen_usher]

Yeah, the keyboard isn't ADB from what I remember. It's the same as the Lisa and I think that it also works with an Apple III(?).

[PhilC]

Yeah, the keyboard isn't ADB from what I remember. It's the same as the Lisa and I think that it also works with an Apple III(?).

I’ll get an adaptor for the keyboard and mouse made up once I’ve tweaked a few other bits like these dodgy cracked Rifas that I’m surprised haven’t let the magic black smoke free yet, they are pretty cracked. Won’t turn it on again until I change them.

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Incidentally this will be the first time I’ve worked on computer equipment with high voltage coils ie the screen. Can anyone please explain or point me to a guide to safely discharge it before working on it.

[rubber_jonnie]

@rubber_jonnie the battery compartment is actually on the back of the case and is pretty clean which makes a nice change.

IMG_2956.jpeg

Typical that it needs a type of keyboard totally different than the LC-II but there are a few adaptor around I can make, one uses an arduino mini which I have loads off.

That's a definite bonus!!

[rubber_jonnie]

Yeah, the keyboard isn't ADB from what I remember. It's the same as the Lisa and I think that it also works with an Apple III(?).

I’ll get an adaptor for the keyboard and mouse made up once I’ve tweaked a few other bits like these dodgy cracked Rifas that I’m surprised haven’t let the magic black smoke free yet, they are pretty cracked. Won’t turn it on again until I change them.

IMG_2957.jpeg

Incidentally this will be the first time I’ve worked on computer equipment with high voltage coils ie the screen. Can anyone please explain or point me to a guide to safely discharge it before working on it.

Ok, so there are some good safety tips here: CRT Safety

I can't stress enough that these things are dangerous buggers and safety first is the prime concern.

Biggest thing for me is don't be alone when working on any CRT and keep one hand behind your back when going anywhere near the anode cap, even if you think it's discharged.

You can buy a discharge wand, which should allow you to see the voltage present when running too. You can make your own wand, I did, and there are tutorials out there that show it, but I'm not going to link to them as you need to decide what's safe for you.

I think the Apples tend to have a discharge resistor built in, but with all that voltage I'd rather not guess and be sure it's discharged first.

[PhilC]

@rubber_jonnie thanks for that. I’m fine with 415VAC and the like just never worked on a CRT before.

I think I’ll order the rifas and leave this to sit for a while before I do anything with it, then follow the discharge guide.