Quadra 605 - 5-Minute Wait for Startup Chime - Capacitor Issue?

[jasonfeinberg]

Hi all, recently acquired a Quadra 605, naturally it got banged up good in shipping. Replaced 3.6V, installed BlueSCSI (although original 160MB SCSI drive still works great), everything works as expected once it boots up - but that's the trick.

The issue is that it takes about 5 minutes from flipping the power switch on for anything to kick in. I flip it on and it's as if the machine is dead. About 5 minutes later, I get the chime, the fan spins, video kicks in, and the machine boots up. It then runs perfectly.

Anyone experience this before? In searching around it seems like most roads lead to issues with PSU / motherboard caps, does that sound like the most likely culprit?

And what is happening during those 5 minutes??

Thanks

 

[volvo242gt]

How new is that PRAM battery? Looks like an older Saft.

I assume you've tried the quick flip with the power switch trick, where you turn it on, then quickly cycle the power again?

 

[zefrenchtoon]

RAM check maybe ?
How much ram do you have ?

Mine with 64 MB is quite long to chime because of RAM check

 

[bobcat]

I think RAM check happens after the chime, and the fan should turn on immediately. My guess is that there's a bad solder connection in the power supply, and once it heats up a little, it works and your computer boots.

 

[Powerbase]

I have 128MB in mine and the ram check takes a minut or so, not five. I would definitely say an issues with the power supply or such, capacitors probably. My two cents.

 

[jasonfeinberg]

Hi all, thanks for the replies. In no surprise, it was the PSU. I found a working one for sale, just arrived today. Swapped it out just now, and the machine instantly boots up as expected.

Still think I want to recap the MB, but at least for now this is a functioning Quadra 605, hooray.

 

[pizzigri]

Use the old PSU as a housing for a new modern Mean Well RPT-60A module!

 

[jasonfeinberg]

Use the old PSU as a housing for a new modern Mean Well RPT-60A module!

A great idea, was looking at that route if I couldn't find a working original. And even though the one I just got works, I don't expect it to last forever so i do want to figure out what it would take do build one with the RPT-60A. I have very few hardware skills and do not wish to electrocute myself, so need to learn a bit more (or have someone do it for me)..