Macintosh Classic II: New restoration project

[BadGoldEagle]

I've just bought myself a "working" Classic II with keyboard & Mouse for €40. That's a pretty good deal, since price for one of these seems to be rising. All keys work on the keyboard. Caps will have to be replaced soon. I just need the right equipment.

Two things are bothering me right now:

1/ The screen is distorted and I can definitely hear a high pitched sound 



When I plugged it on last night to backup its HD using my Floppy EMU (in HD mode), I heard a really high pitched noise coming from the computer. It became louder and louder as it was transferring files. I thought to myself, there's a dying flyback in there. Then it stopped emitting any sound at all. 30 seconds later a very low pitched noise started, as if the HD couldn't spin. (I have an old SONY HD40SC drive that can't spin anymore, the sound coming from the Classic II was similar)

But it completed the file transfer without exploding. 

I thought the HD was on its last legs, but apparently no. Disconnected the HD, it still does that 2mins after switching it on.

So I find myself with a dying flyback transformer. It's a E58491 MTI-LTM-002, part number 157-0129. 

I don't think I can replace it with one from a Plus or SE. IMO, they're not compatible.

Anyone knows which type of Flyback I should replace it with?

Found an old one on ebay FOR $127 !! 

Here's what it looks like:



I read that a failing flyback can cause a distorted screen. It's either that or bad solder joints or maybe it needs yoke adjustments? I tried adjusting the vertical centring control on the back of the unit. It won't help. Toothpicks work as an hex key alternative 

What do you think I should do next apart from ordering a new flyback?

2/ Microphone holder

Previous owner stuck one of those on the side of the unit. Don't really like it. I want to remove it

But I'm afraid I might damage the case. Anybody successfully removed one of these before without making a mess of the case?

 

[Elfen]

Do an analog board partial overhaul - replace the usual suspects (T1 - the flyback, Q1, C1 so on... then desolder, clean up and resolder with fresh solder the jacks where the wiring harness go to). Then reinspect the screen again. Then make what adjustments you need. Check around the yoke, there should be a ring with little black squares on it. Those are magnets, make sure none are missing from that ring (a gap will be there is is missing).

And recap that logic board as soon as you can!

 

[J English Smith]

Re the mic holder, you can work a thin blade screwdriver in the sides and rock back and forth a bit gently to losen it. If you can get an edge started, you can apply gentle pressure to pull it off. Slip a think cookie sheet or something like that under the blade to prevent scraping the case unduly.

Good luck, I just sold off mine here in Des Moines. Nice machines, just couldn't think of anything to do with it anymore!

 

[rushfan82]

Those little pink squares around the yoke are geometry magnets. I had to adjust that on my Mac too. Twist those until the image becomes a square, and there should be 8 of them, each corresponding to a corner/side of the screen.

 

[bibilit]

What do you think I should do next apart from ordering a new flyback?

Bring it to me tomorrow, i will have a look at it...

 

[BadGoldEagle]

Thanks again bibilit for checking it out today.

Turns out the hissing problem was due to leaking capacitors on the analog board. Now it's gone!

You were right Luis! Thank god the flyback is ok! It's nearly impossible to find a replacement unit for a Classic AB!

The distorted screen issue is nearly gone. I will fine tune the display next weekend. I just need some protecting gloves. The magnet is right against the AB, and I don't want to shock myself

Now it's much nicer. If the weather is good, I'll be doing some retrobright next week end.

 

[bibilit]

Thanks again bibilit for checking it out today.

You are welcome 

You have found a nice unit, with little care you will have a great Classic II.

And no, the weather isn't good, your SE front casing is expecting some sun to get a bath. 

 

[BadGoldEagle]

Well, today I made a backup of my SE/30 HD to an external SCSI2SD. I wanted to connect the scsi2sd and the floppy EMU to my newly acquired Classic II so I could backup the scsi2sd to a 160mb partition on EMU. 

BUT, when I turned my Classic II on, it started making that terrible sound again!

Mac Classic.mp3

Recorded using my iPhone's speaker.

Bibilit replaced a couple of caps on the A/B that had started to leak. I know I'll have to replace all of them in the near future but do you think an AB recap can fix this?

 

[Macdrone]

Yes, might do a search but also those speakers do fail, the speaker itself, also those logic boards still have sound on them and software controls the volume so if it was gooey before recap on the logic board, may need another good cleaning also.

 

[tanaquil]

OMG, that sound is awful. I hope you figure it out!

 

[Paralel]

Does it do it with the minimal hardware connected (nothing external, internal mass storage disconnected) required to boot the system? If not, then it is the A/B, and it can't handle the strain. If it still does it with minimal hardware, could still be the A/B.

 

[BadGoldEagle]

It does that with nothing connected at all: no floppy nor HD and no System! And the voltages coming out of the molex connector are good. Odd.

It's either the speaker or bad caps all round (LB and AB not recapped, yet...)

I should try this with the logic board disconnected, see if it makes a difference.

Oh and by the way, those magnets on the Yoke will fix a distorted display.

 

[LazarusNine]

I have a Classic that exhibited almost the exact same sound issue. That was sorted after a full recap of the logic board and analogue board. Hopefully the same works for you!

 

[BadGoldEagle]

That's interesting. Thank you for your feedback.

If all else fails I guess that's what I'll do.

 

[LazarusNine]

For sure. I should add that the board got a good clean in isopropyl alcohol as well to ensure any cap goo wasn't interfering in places.

 

[BadGoldEagle]

I haven't worked on that Classic II for a long time now. BUT. I bought a second hand soldering station. So hopefully I'll be able to fix that awful sound!

I'm gonna practice on a LCII I got for free a couple of months ago, next in line is the Classic II's AB!