Mac LC-II restoration

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Mac LC-II restoration

Postby SpidersWeb on Wed Jul 18, 2012 8:29 am

So my $1 Mac LC-II with keyboard and mouse arrived last night.

As per description, it powers up but doesn't bong. Hard drive spins up and then down, the fan turns on and stays on, but no response to the wake up button on the keyboard. The interwebs led me to replace the battery first (apparently it wont power up with a dead one) so I've ordered one off trademe and just waiting for delivery. 3.6V non-rechargeable Lithium 1/2 AA.

I've removed the original, and it's dated May 1991, I never tested the voltage but it would be a miracle for a non-rechargeable battery that's been used to still have charge after 20+ years.

If the new battery doesn't fix it, I'm guessing the problem is likely the "unusually clean area around capacitors". The board is covered in dust except magically around a big area of capacitors - so it may need a bath. No other visible faults stick out.

This is actually my first Mac, ever.
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Re: Mac LC-II restoration

Postby tezza on Wed Jul 18, 2012 10:03 am

SpidersWeb wrote:If the new battery doesn't fix it, I'm guessing the problem is likely the "unusually clean area around capacitors". The board is covered in dust except magically around a big area of capacitors - so it may need a bath. No other visible faults stick out.

Highly likely that is the problem. It may not need a bath, just a good swab down around the affected areas with isopropyl alcohol and cotton buds.
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Re: Mac LC-II restoration

Postby SpidersWeb on Wed Jul 18, 2012 10:18 am

Cheers for that. Yeah I guess a bath is a bit overkill. Need to grab some more isopropyl as well. I just wish my nearby DSE wasn't a Noel Leemings in disguise :/ going to have to go for quite a walk.

The battery should be delivered today, so will see what difference that makes (if any).
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Re: Mac LC-II restoration

Postby Carcenomy on Wed Jul 18, 2012 6:10 pm

SpidersWeb wrote:I just wish my nearby DSE wasn't a Noel Leemings in disguise :/

They're throwing away the Electronics side big time, last time I went in there I just wanted a couple of RCA connectors. Nope, they'd thrown out every item from those shelves, quit stocked and in the skip.
If you're looking for Isopropyl the wife just bought some from Mitre 10 Mega, didn't work at all for what she was wanting to use it for but works awesome for cleaning Mega Drive cartridges :)
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Re: Mac LC-II restoration

Postby SpidersWeb on Wed Jul 18, 2012 11:03 pm

haha awesome

Well I installed the battery, no change.
Used an isopropyl static free wipe around the caps, no change.
Removed extra RAM SIMMs, no change
Washed the board, rinsed the board, wiped the board down with iso, and dried - still no luck.

The fan and hard drive start up, then the hard drive spins down and just nothing. No chime, no flicker on the screen even.
I'm sure it's actually firing up, just not initialising, all the normal chips come up to temperature including the 68030 CPU after pressing the keyboard button and waiting a few minutes.

I noticed when it arrived the motherboard screw was missing, so I suspect it's been fiddled with previously. So I have no idea what to do next, besides wait for another to arrive on trademe. I'm 95% sure it's a board problem.
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Re: Mac LC-II restoration

Postby Gibsaw on Thu Jul 19, 2012 11:04 am

There are all sorts of places you can start..

First things first... if there is a screw missing, make sure it's not floating around. (although if it is, the damage done will be too late.)

Then, given that those caps are now minus their electrolytes... It sounds like you have some caps to look at replacing.
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Re: Mac LC-II restoration

Postby tezza on Thu Jul 19, 2012 12:26 pm

Gibsaw wrote:Then, given that those caps are now minus their electrolytes... It sounds like you have some caps to look at replacing.

Yep. There is a good chance the caps have just lost too much of their electrolyte and the capacitance is now out of tolerance.
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Re: Mac LC-II restoration

Postby SpidersWeb on Thu Jul 19, 2012 4:33 pm

Yeah the screw isn't loose, it's just missing.
I checked out the case when I refitted the motherboard just to be sure there was no shorts.

I was thinking cap failure too, but I could probably spend an entire day replacing all those tiny caps and without a desoldering station it's likely the result wouldn't be the cleanest. Long term I'm going to need to be a pro at this, but right at the moment avoiding it unless necessary. If I could visually identify a faulty component or two I'd jump on it, but they all look new (except the puddle).

If there is anything else I should try or try again, I'm keen. Quite like these little LC macs.
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Re: Mac LC-II restoration

Postby recycled on Thu Jul 19, 2012 4:36 pm

Gibsaw wrote:First things first... if there is a screw missing, make sure it's not floating around. (although if it is, the damage done will be too late.)

Spot the guy who's never had to do work on a real Mac! ;o)

What monitor are you using? An apple one or a PC VGA screen with an adapter? Are you starting up with the VRAM SIMM present? Are the ROMS in the correct sockets? (In my LC2 they are labelled 341-0473 in socket UB2 LL to 341-0476 in UE2 HH, someone may have tried the old 'pull and re-insert the ROMs trick' and messed that one up). Unplug the HDD and the floppy - does anything flash on the screen when you power it up like this? You should also try a PRAM reset now you have a new battery - the old one may have just had enough to keep a bit or two floating.
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Re: Mac LC-II restoration

Postby Gibsaw on Thu Jul 19, 2012 4:42 pm

recycled wrote:
Gibsaw wrote:First things first... if there is a screw missing, make sure it's not floating around. (although if it is, the damage done will be too late.)

Spot the guy who's never had to do work on a real Mac! ;o).

How so?
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Re: Mac LC-II restoration

Postby SpidersWeb on Thu Jul 19, 2012 5:39 pm

recycled wrote:
Gibsaw wrote:First things first... if there is a screw missing, make sure it's not floating around. (although if it is, the damage done will be too late.)

Spot the guy who's never had to do work on a real Mac! ;o)

What monitor are you using? An apple one or a PC VGA screen with an adapter? Are you starting up with the VRAM SIMM present? Are the ROMS in the correct sockets? (In my LC2 they are labelled 341-0473 in socket UB2 LL to 341-0476 in UE2 HH, someone may have tried the old 'pull and re-insert the ROMs trick' and messed that one up). Unplug the HDD and the floppy - does anything flash on the screen when you power it up like this? You should also try a PRAM reset now you have a new battery - the old one may have just had enough to keep a bit or two floating.


ROM:
I don't think mine has sockets, everything looks soldered in, but I'll double check tonight and report back.

Screen:
I'm using a MAC->VGA adaptor and an IBM PS/2 VGA (640x480) which is tested as working.

Bootware:
VRAM SIMM is installed. Brand new 3.6 Lithium 1/2 AA battery installed (and I cleaned the contacts).
I have tried HDD only, both installed, and both unplugged, no change. Also tried monitor attached and not attached.

PRAM:
With the old battery removed and power cable disconnected, I left it for 24 hours, and shorted the battery-holder terminals. I was really hoping it was corrupted PRAM. Although I just looked up the startup key stroke for resetting via the keyboard and I had it wrong, so I'll try "Command-Option-P-R keys" tonight. I was holding R but not P as well. Worth a shot.

Edit: I should add that on some occasions after hitting the keyboard button (maybe once or twice in all my testing) I did get a click from the speaker. Click sounded like the normal noise when you turn a small amp on, I had a bit of a rush for a second when I heard it because I thought it was alive, but no bong :(
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Re: Mac LC-II restoration

Postby SpidersWeb on Fri Jul 20, 2012 7:45 am

Ok, so the 4 ROM chips are definately soldered in and look untouched.

But I did make it do something. Previously I'd had the brightness turned up on the VGA to make sure I could see any activity - so I'd get this light grey square taking up most of the display. Last night I did the PRAM reset via the keyboard, and now when the Mac is on that grey box gets smaller (I'm guessing because it is set to 512x384). The PRAM definately should've been reset before, but hitting those keys certainly changed the video mode.

The lines of the box have zigzags down each side and I see extremely faint blue lines. The image never flickers or changes, and it appears with the VRAM SIMM removed - so I'm guessing it's not actually a display - but it indicates that it responded to my key stroke at least.
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Re: Mac LC-II restoration

Postby recycled on Fri Jul 20, 2012 5:21 pm

OK, let's see how deep we can get this quote box!
Gibsaw wrote:
recycled wrote:
Gibsaw wrote:First things first... if there is a screw missing, make sure it's not floating around. (although if it is, the damage done will be too late.)

Spot the guy who's never had to do work on a real Mac! ;o).

How so?

A 'REAL' mac is a joy to work with as EVERYTHING clips together. The first case design to use screws was the Quadra 800, which earned it the first 'Road Apple' honor. (If one was in the middle of the road with a 40ton truck barreling down on it you wouldn't bother to run out and rescue it). While the drives use screws to secure them to drive sleds or as locator pegs the motherboard is just a clip or two away from freedom. So there is no excuse for a loose screw in an apple case - unless someone is playing a prank on you - like a radiator for a VW (excluding oil coolers please!)

Back to the ailing LC.

Ditch that PS/2 monitor and grab some no-name multisync/multi-frequency monitor if you don't have access to an apple branded one from this era. The IBM monitor has a fixed frequency, 'use with recommended hardware only' ;o) Even worse if it's one of IBM's 13" models. Use the VRAM SIMM if you possibly can, this will give you better refresh rates and colours. With a 512kB stick access to VGA 640*480 and thousands of colours is available, but of course now the system is reset, it's doing it's mac thing at 512x384 - and it sounds like you have a signal that should turn out to be a startup screen.

You should get a 'sad mac' image on screen (with a decent monitor) which will give a number for the error that is stopping the machine.

That's 'good' news about the ROMS, one possible issue eliminated.

I'm still looking, but the caps near the processor appear to be part of the audio circuit and LC slot power circuit, if they are past the 'use by date' it may explain the silence your machine is exhibiting - but should not be responsible for stopping the computer working.

(whoops quick edit to fix my poor grammar)
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Re: Mac LC-II restoration

Postby Carcenomy on Fri Jul 20, 2012 6:55 pm

Surely you can find an Apple display? I have multiple spares but shipping them north could be an ordeal.
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Re: Mac LC-II restoration

Postby tezza on Fri Jul 20, 2012 10:43 pm

recycled wrote:A 'REAL' mac is a joy to work with as EVERYTHING clips together. The first case design to use screws was the Quadra 800, which earned it the first 'Road Apple' honor.

Are you sure? I could have sworn my Mac Classic II, SE30 and SE had screws inside for various bits and pieces?

I'm not going to crack one open to check though. :)
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