Colour Classic Won't Start -- Need Help

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Colour Classic Won't Start -- Need Help

Greetings all,

I recently purchased a Colour Classic, and it is behaving a bit odd. It will only startup if I remove the l/b, turn on the machine, and shove the l/b back in. After that, everything works just fine.

Initially it wouldn't start at all, so I took it apart and checked the a/b. Everything looked fine, and the voltages were reading correctly. I knew the power cord was good, but I tried another one anyways, and turned on the machine. It booted up normally. The hard drive was spinning, but the screen was blank. I then realized that I hadn't put the l/b back in. So I shoved it back in. Lo and behold, I heard the system "bong", and the screen had the "? disk" icon. I have an original copy of System 7.5.3 on floppies, so I went ahead and installed it. Now it works great. I just have to do my little "trick" everytime I want to use it.

I am certain that it isn't the a/b, since it works just fine. I don't think it's the PRAM battery, otherwise it would start even after I shove the l/b back in. I'm thinking the contacts on the l/b might be bad, but they look fine to me. Perhaps it could be the contacts on the inside.

I was wondering if anyone has any suggestions or has experienced anything like this before. I would appreciate any help you all could offer.

coius's picture
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clean the contacts

clean the contacts with a small cotten swab and a little bit of rubbing alchohol. if you can get long enough swabs, try to clean the contacts on the receptor. that might take care of the problem

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o_________O might be a rid

o_________O

might be a ridiculous question, but... did you try pressing the Power button on the keyboard after you flicked the switch on the back of the machine?

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Cleaning the contacts inside

Cleaning the contacts inside the case seems to have done the trick. Now the only problem is that there is now sound. I know the speaker works because I hooked it up to a wave generator and it produced sound. I traced the speaker wires back to the a/b and didn't notice anything wrong. I haven't tried to see if the headphone jack on the back is working, but will try that when I get home.

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tried the CUDA switch? that f

tried the CUDA switch? that fixed a CC with exact the same behaviour. and maybe the sound will come back by doing so. you never know.

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Similar but worse problem

Hi all,

I have a dead Color Classic with somewhat similiar behavior to the original posters-

1. No PRAM battery so I assume that's not the problem.
2. If the logic board is out, then the machine will start up- I hear the fan and the hard drive spin up (so far so good).
3. But when I stick the logic board in, the machine shuts off completely (boo).

I tried cleaning the contacts on the board and the socket, but to no avail.

Would these signs point towards a bad logic board? I would love to get this unit working, but don't have any other Classics to troubleshoot with.

Thanks! Steve

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... although not insurmountable

MMM

Apple divides its power-control sytems into 'passive' (with nothing but an AC switch at the rear of the Mac to start it) and 'active' (with inbuilt power-control circuitry, and a so-called 'soft power' switch on the keyboard for startup, but no AC switch behind).

Of course there is an exception to this division, and the CC is one of the exemplars. It has an AC switch behind, and a soft power switch on the keyboard (if it has its original or a suitable alternative). Its power-control system is called pseudo-soft by Apple.

Given that you have cleaned and inspected the logic board and fan, inserted RAM and VRAM if those are missing, replaced the PRAM battery with a known-good half-AA 3.6V lithium cell (or a Rayovac 840 4.5V alkaline battery for MLBs of the CC's 'middle period'), checked that FDD and HDD are present and connected, and worked the logic board in and out of its connector several times to clean the contacts, and pressed the CUDA switch (near the ADB ports) if one is present, switching on the AC should give an audible resonant 'clunk', as of a relay pulling-in. Now the soft power key on the keyboard should initiate startup.

If, however, pressing the keyboard's power key produces one or more audible clicks, and blinks the front green power-on LED in sympathy for as long as you hold the key down, you have met a CC that has not been in use for quite some time. The remedy is to leave the CC set up, with the AC power switched on, for up to 24hr, trying at (say) hourly intervals to start up with the keyboard switch. If one of these attempts elicits the POST chime, you are on the way with a demonstratedly working logic board.

If you get the chime, you can apply all the usual responses to the failure to see the subsequent requisite 'mileposts', in order: screen raster, on-screen pointer, Happy Mac icon, splash screen, march of the icons, and finally, the Desktop. Listen (or feel) for signs of HDD spin-up, but be prepared for the possibility that a Disk Tools floppy disk may be needed to boot from, and perhaps to repair the HDD or reinstall the HDD driver.

If you do not get the chime within 24hr, which is rare indeed if the CC is capable of working, leave the CC another 48hr with the same regular checks. If you still get no joy, it may then be time to break out a larger hammer.

de

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so it must the LoBo. I tried

so it must the LoBo. I tried a known good analog board and the same thing: blinks the front green power-on LED in sympathy with keyboard's power key.

What in the LoBo can be bad? Capacitors or else?

Ben

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another dead CC

grannysmith wrote:
MMM
If, however, pressing the keyboard's power key produces one or more audible clicks, and blinks the front green power-on LED in sympathy for as long as you hold the key down, you have met a CC that has not been in use for quite some time.

My CC after the analog board swap has worked for a while, then I moved it to the basement. Now it does not boot: I just get the green blinks and the fan starts very slowly as long as I keep pressed the power button on the keyboard. Nothing else. I tried everything suggested here.

Should I go for analog board inspection or logic board recapping after dishwasher?

Ben

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Re: Colour Classic Won't Start -- Need Help

I have now two dead CC logic boards, same symptoms. I recapped both with no luck.

Anybody knows what gets deteriorated, besides aluminium capacitors?

Thanks,

Ben

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The cause is the analog board

I tested all supposely dead logic boatds on a working LC 575 and it always booted fine (just said the System is not the correct one...), so the cause of this weird behavior (no boot, clicks and green light blinkin) is in the analogue board.

Will a good old TV techician be able to repair the analogue board?

Ben

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