7600 strange issue

[marmotta]

When I push the power button the mac startup, but not chime and black screen... turn off, turn on... work like a charm!

It is always like this, I have to turn on, off, and turn on again

Why?

 

[Byrd]

Try replacing the PRAM battery first

 

[marmotta]

Pram is ok, 3,6v and not loose the clock. I suspect the problem is only with monitor attached at pci graphics, not with onboard video

 

[Byrd]

Try the PCI graphics card in the slot closest to the CPU, and reset the PRAM/CUDA

 

[marmotta]

Tried

First boot ok!

Turn off... Turn on, black screen

Turn off, turn on... Ok

Mistery... perhaps the problem is software powerdown?

 

[trag]

Pull the CPU card and carefully clean the edge connector contacts. I've had good luck with glass foaming cleaner and a microfiber cloth. If you want to clean the socket as well fold some card stock, e. g. 3" X 5" card, soak the folded edge in alcohol and gently insert and remove from slot a few times.

While you have the CPU card out try powering up. I think you'll find it's just like the problem you're experiencing. The x500, x600 series will power up with no CPU or ROM, although it won't do anything afterwards. Power up is controlled from the CUDA chip.

 

[marmotta]

Nothing... I cleaned all with dry contact cleaner! I going crazy!

-Reboot always ok

-After power off (with keyboard or power button) mac will not start.

-After power off, power on (mac not start), power off, power on... mac start without problems!

-When mac not start I ear the speaker try to reproduce a chime but stop at first second and I listen a "crank" from the speaker...

-I think is the caps but I have tried to power off, power on (not start), power off..... wait one hour.... mac power on ok! Another test is power off, power on (mac not start), power off... disconnect powercord, power on (caps discharge)... when I power on the mac start correctly! This is exclude the caps?

 

[marmotta]

I tried all ram configuration, with and without pci graphics, boot from cd... nothing

But there's something new! The problem (partially) not exist!!! I not listen the chime, the screen remain blank.... but if I wait 45 seconds the screen appear!!! And at 65 seconds start to load macos!

Is not normal.... true?

 

[604ev]

I had a maybe similar problem with 1 or 2 bad (but working) 128Mb memory dimm on a 9600 with PL G3/500:

cold boot : OK, computer never crashes
reboot : chime + black screen + nothing

upgrading CPU to 1Ghz PL G3 would definitly not work with these DIMM : same problem upon reboots + cold boot ok but computer crashed after some time.

marmotta said : " if I wait 45 seconds the screen appear "
This is normal to me, as it happens every time after a hardware configuration change (PCI slot or RAM). Could even be more than 1 minute depending on the 9600 config..

So I'd first try known working Dimms in the 7600.

+ Info : ONCE AGAIN the PowerMacs RUN FINE WITHOUT PRAM BATTERY. Without it, the only issue, ONLY after it has been unplugged from DC Power is, except a date/time loss, an NVRAM reset, which is not a problem as long as Mac runs OS 9 and has networking time. Not even a problem if you run OSX and the Mac never gets unplugged from power source.

 

[marmotta]

Is normal wait one minute for system start load? Yes on changed config, but I wait one minute every time I powerup the mac...

I tested my dimm's with Apple diagnostic and appear to be ok. I have cleaned, moved, tried another dimm... Nothing change. Now I have 416mb with 8 dimm.

Remove the battery is possible solution? Why?

 

[604ev]

Removing battery is not a solution here, i was answering some of this topic's previous posts. But you can safely remove it, and you should do so if it's too old (before it leaks).

Is normal wait one minute for system start load? Yes on changed config, but I wait one minute every time I powerup the mac...

I saw that once : there were both 60ns (gold connectors) and 70ns (silver connectors) DIMMs in a PowerMAC... maybe even that Interlaving was OK, I can't remember.

If you currently don't simultaneously use 60ns and 70ns in your 7600, there's a chance that one DIMM is not so good, or interleaving is too strange..

You should start diagnostic with minimal RAM config..

 

[marmotta]

If is a ram problem, is a normal not listening a chime? I listen a chime only if I power down (during one minute wait) and power on (system start without delay)

 

[604ev]

yes it is

although it could be something else

please let us know your RAM config (interleaving & size & connector color for each module)

& once again

You should start diagnostic with minimal RAM config.

OS 9.1 will work with 1x 32mb module and no VM with extensions disabled

and no pci of course; you could even unplug any device such as zip or cd rom

and remove your pram battery as it's too old

 

[marmotta]

Actual config is:

Sonnet crescendo G3 400

GFX TwinTurbo128

Atto scsi uw with 73 gb hdd

Cd-Rom at scsi onboard

Ram: 6 modules 64mb 6ns gold, 2 modules 16mb gold. In pair... A1,B1 etc...

I already tried with different memory layout (128mb to up), without gfx, without cd-rom, with original cpu and without ATTO... with no difference. But when I have time I wanna retry

 

[604ev]

well

nvram reset could be needed

remove power cord, remove pram battery, and try again in 24 hours with minimal config (minimum ram no pci) (stock cpu or g3)

just remember nvram has to be reset via cuda ( or removing battery powercord etc) each time you swap cpus

 

[604ev]

PS

the AV card should be unplugged too for testing..

and use original hd & internal scsi please

 

[marmotta]

One question: my dimm of 64mb have some small chips, 16mb dimm have 8 big chips... perhaps 64mb is fpm and 16mb is edo???

 

[604ev]

big chips are older

no matter edo/fpm, both are compatible and work as fpm

just minimal-compact the config and 24 hour out of power your mac then startup

then if it doesn't work just go to a friend that has pci powermac and test your hardware

otherwise recap mother and daughter boards, as well as the psu

or get a mach5 9600

sincerly yours,

604ev

 

[marmotta]

big chips are older

no matter edo/fpm, both are compatible and work as fpm

just minimal-compact the config and 24 hour out of power your mac then startup

then if it doesn't work just go to a friend that has pci powermac and test your hardware

otherwise recap mother and daughter boards, as well as the psu

or get a mach5 9600

sincerly yours,

604ev

I already have 9600 but not work... from the psu out 24v instead 12v from the small connector. I suspect did have damaged the logic board (i tried to send 12v instead 24v without success)