IIx Dead

[patatas]

I have recently acquired an Apple Macintosh IIx which does not power on. No chimes, No nothing.

I have replaced the power supply and both batteries but still nothing.

Power on tests include removal of ALL adapters but still nothing.

Any ideas ?

 

[JRL]

Check the motherboard for leaking caps.

 

[Unknown_K]

Make sure the batteries are installed correctly (+ and - in the correct orientation).

Does the PS click at all when you try to turn it on?

Check for leaking capacitors and that the ROM SIMM is installed.

 

[patatas]

ROMM SIMM installed.

Power switch in the back (and ones on the side) all click.

No idea how to check capacitors

 

[Unknown_K]

Can you take a decent picture of the motherboard with cards removed?

 

[Osgeld]

No idea how to check capacitors

look for goop around metal cans

 

[patatas]

No visible goo from capacitors

Image with Processor card.

Image w/out Daystar Processor Card

 

[Unknown_K]

What is that crud by the RAM (dust or did somebody break off the retaining tabs and glue the RAM in)?

Also looks like you might have RAM that isn't matched in one bank.

Try removing the accelerator from the equation (stick in any 68030 processor you have into the motherboard socket).

 

[patatas]

Memory slot tabs are broken and RAM is held in place with little bit of dough (i think)

I will try to remove ALL ram one pair to see if the helps and will add CPU directly to board...

 

[Unknown_K]

It originally had a 68030/16 so any 68030 should work when installed.

 

[patatas]

No luck even after the MC68030 which was 'borrowed' from a working Mac.

 

[joshc]

Surface mount caps can leak from underneath and sometimes you wont see the goo until you remove them. Capacitors inside the PSU itself are probably due for replacement anyway.

 

[patatas]

PSU is a refurb I purchases as initially I thought it was faulty.

As I have no idea how to test the onboard capacitors I will have to replace them all. oof

 

[Osgeld]

Surface mount caps can leak from underneath and sometimes you wont see the goo until you remove them.

9 out of 10 times i hear that i think people are mistaking old flux freshly re-wetted by the heat of soldering

 

[joshc]

As I have no idea how to test the onboard capacitors I will have to replace them all. oof

Well that's a good thing anyway, as they are over 20 years old!

 

[Unknown_K]

I recapped both of my IIx systems and the IIx spare motherboard, they are reliable now. Not realy that many capacitors (or values) needed.

 

[JRL]

Make sure you installed the batteries correctly and they're the type that are supposed to be soldered.

If I were you, I would install 3.6 V battery holders so you don't have to bother soldering when the batteries die again.

 

[trag]

Memory slot tabs are broken and RAM is held in place with little bit of dough (i think)I will try to remove ALL ram one pair to see if the helps and will add CPU directly to board...

The RAM must be installed in matched sets of four. If you're only installing a pair, that is a part of the problem. However, if the speaker is working, I think you would get an audible error code with a pair of SIMMs installed, if the motherboard is otherwise functional...