Quadra 700 shutdown question

[Peter-Erik]

Hi all,

get an Quadra 700 before I started the Mac I did first a recap of the Power Supply is start and runs. It boot form an external BlueSCSI
But when I do a shutdown is see an messahe "It is now safe to switch off your Macintosh" is this normal? and if yes how do I shutdown it?
If I hold the power button nothing happen it keeps running.

any idea? thanks

 

[chrisrueckert]

No, the Quadra 700 should shut down completely. Did you try a clean install of the system? Or with another working PSU? I am not sure if the shutdown behaviour is fully managed by hard- or software, hence the thought.

 

[Peter-Erik]

Have no other PSU for test , have no internal HD need to buy a bluescsi for intern but test it with an db25 bluescsi first. So you think that the screen message is not normal?

 

[chrisrueckert]

You wrote that nothing happens when you pushed the power button. Which button did you push? The one on the keyboard or the one on the back of the Quadra near the power plug?

An internal HD is not needed to do further testing. Your BlueSCSI can hold a couple of hard disk and CD ROM images from which you can install a clean, new system for the Quadra. Or you could download one that should work fine. More here: https://bluescsi.com/docs/BlueSCSI-Images#Macintosh

 

[Peter-Erik]

Back on the Quadra

 

[croissantking]

Yeah this isn’t right, the Quadra 700 has soft power circuitry.

 

[Peter-Erik]

@croissantking thanks for message

 

[cheesestraws]

Yes, this is the fallback if soft power isn't working. Try a new OS installation first, but it may be a hardware issue.

 

[croissantking]

It’s interesting because it’s usually leaky capacitors that harm the startup circuit on models such as the IIci but the Q700 has only tantalums. Still, you should have a look at the board and see if there’s any damage caused by something else.

 

[finkmac]

pretty sure the psu partially controls the soft power.

i mean that's what provides the power trickle for the boardside soft power to work... right?

a similar thing will happen on IIsi units. the caps on the soft power control board leak and this message starts popping up.

i'd check the PSU recap job. which PSU model? did you clean any leaked capacitor fluid? etc

 

[cheesestraws]

Yeah, when I say 'hardware issue', I'd absolutely include the PSU in the definition of 'hardware', and in the case of a 700 it may be the most likely candidate.

 

[Peter-Erik]

PSU this model ASTEC AA15830

Used https://68kmla.org/bb/index.php?threads/iici-power-supply-recap-and-component-identification.41364/

as replacement guide

DigiKey list
is the list I used

Clean so much as possible with Isopropyl alcohol

Checked the board and don't see anything strange or damaged, is there a certain area to look?



The only thing in the list whicht is not replaced is C6 (Between C9 and C8) could it be the issue?

​

 

[Peter-Erik]

Replaced C6 and it is now working shutdown works

(C6 was weird, two capacitors serial connected)