SE/30 turning on very slowly

[q700fan]

I have an SE/30 that turns on very slowly.

I don't mean the memory test, what I mean is that when I flip the switch it sometimes takes a full minute or two before the chime occurs. It is almost like a capacitor in the power supply or on the analog board needs to charge up or something.

Is this a common fault and has anybody else experienced this?

 

[rickrob]

Have you checked the power supply voltages? You can check them on the 19 pin floppy connector

 

[q700fan]

+5.00 V and +12.3 V read fine

The -12.0 V gives me 0.0V

Note that these readings are after it has booted up

 

[rickrob]

What are the voltages on power up, when you have no chime?

Has any work been done on this machine-- re cap logic board or analog board?

 

[q700fan]

Logic board was recapped by a previous owner. I'll need to leave the machine unplugged overnight to get the no chime scenario and check it tomorrow.

 

[q700fan]

All readings are 0.0 V until the things springs to life a couple minutes after being turned on. Obviously a power supply issue- but what specifically?

 

[3lectr1cPPC]

A PSU taking a while to start up sounds like a textbook case of weak capacitors to me, but with power supplies it could always be something else. Unless you're really good at troubleshooting switch mode power supplies, I'd recommend just recapping it.
Console5 has cap kits: https://console5.com/store/computer-cap-kits/mac-68k-cap-kits/se-30.html
Make sure you get the one that matches the brand of PSU you have.

As an alternative option, or if a recap doesn't fix it, you can also just replace the original supply with a modern unit with a bit of work.

 

[rickrob]

I would re-cap the analog board and power supply, or

This thread has lots of info about using a modern power supply.

https://68kmla.org/bb/index.php?threads/modern-psu-for-the-se-30.30945/

I did this on one of my SE/30's with a Seasonic SSP-250SUB. Installed it in the Astec case. If you have an Astec Power supply this might be an option. The Astec's have good ventilation.

 

[rickrob]

Seasonic in the Astec case.

 

[thlnk3r]

Seasonic in the Astec case.

View attachment 72086
View attachment 72084View attachment 72085

Rick,

This is pretty awesome. I did something similar with my Q950. Would you mind sharing the pin-out for the SE/30 to 24pin connector?

 

[rickrob]

Rick,

This is pretty awesome. I did something similar with my Q950. Would you mind sharing the pin-out for the SE/30 to 24pin connector?

The power supply is in a machine, but I can make a drawing from the info and pics I have.

 

[thlnk3r]

The power supply is in a machine, but I can make a drawing from the info and pics I have.

Thanks. Really appreciate it. I mean I can probably figure it out from one of your posted images but I just want to be sure ...

 

[s_pupp]

See also this thread regarding psu alternatives, including the Seasonic.

 

[q700fan]

I replaced the PSU with another unit and everything works fine now. What a pain though.

 

[rickrob]

Rick,

This is pretty awesome. I did something similar with my Q950. Would you mind sharing the pin-out for the SE/30 to 24pin connector?

I drew this up from the info I had-- please double check this and let me know if anything is incorrect.