Takky power supply question

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I'm in the process of building my first Takky, and I've got all the physical case modifications done (I've fit the wiring harness in the correct spot, lengthened the slots for the logic board, rewired a wiring harness, and I've performed the VGA modification to the analog board). I'm planning on using a Quadra 630 power supply as the PSU for the logic board and HD.

I wired it up dry last night. I pulled the 5v, 12v, and two ground lines from the analog board to the PSU from the PSU's molex connector. (So no power supply is coming from the A/B to the logic board. On the 630, these lines would have gone to a CD-ROM, so they can't be critical to the PSU's operation.) I connected my 630 PSU to my wiring harness (also from a 630 - aka the infamous "630 connector"). And I fit in a Q630 motherboard (I've got a 5500 board, but I haven't done the 3.3v regulator yet).

Anyway, I plugged the AC supply into both the A/B and the 630 PSU. Upon flicking the switch on the A/B, I heard the CRT charge up. I pressed the power button on the keyboard, and nothing happened.

The 630 supply is a soft-power switched supply. So it needs an ADB pin shorted to ground to start, right? How do all you geniouses get your 630 supplies to power up when the 630 PSU isn't connected to your Mac's ADB lines?

I tried shorting the ADB power sense line to ground on the 630 PSU, but that didn't do anything.

Can you all help? I can't figure out how to jump start my 630 PSU. And if I can't get it working now, I can't imagine how I'll get it working with a relay.

Also, can someone tell me which line on the wiring harness is supposed to carry 3.3v for PCI logic boards?

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Drew

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Darn Double Post

Mods, can you delete one?
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Drew

Done! -eeun

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One more thing

A couple things I didn't mention, but I'll include for completeness.

I didn't connect the button board as I intend to use the 630's buttons and IR module (also unconnected). I didn't connect up the floppy drive, but I did connect an IDE drive. I've removed the SCSI ribbon completely. I can't imagine that any of that would make a difference, though.

Thanks!
Drew

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Hmm. . . . .

The 'standard' approach to adding extra PSU capability has been to use the CC's PSU (ie the A/B) to power the logic board, and use any extra power supply to drive the HD. The mains to the extra PSU piggy-backs off the back of the usual mains i/p to the a/b, and the output is controlled by a relay activated by the normal a/b supply. This avoids the problem of starting an auxilliary PSU.

In your case, there must be a 'sense' i/p of some kind to the PSU from the 630 l/b. That may be level or edge triggered. I'd reinstall the PSU in a 630 and see what happens to various lines when you power the machine up.

Stuart

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Load

One of the walls I kept hitting when building my Takky was I didn't have enough of a load on the second PSU for it to supply power.

The required load I'm sure varies from supply to supply, but you might want to try triggering your 630 power supply separately with their intended load before working out how to trigger the 630 PSU from the CC.

I had the second PSU - a small one from All Electronics - supplying my hard drive, and supplying 3.3V for the 6360 board's PCI functions. It wasn't a soft-on variety, so I just used a relay connected to the analog board's 12V line.

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Thanks.

Thanks to both of you. If I'm hearing you right, you're indicating that the CC analog board supplies enough power for a PCI-class board. Is that true even if running a full load of dual PCI cards, G3 upgrade, 128 MB RAM, AV module, TV/FM tuner, and Comm slot ethernet card? If so, I'll skip the 630 PSU as it's overkill for just powering a hard drive.

I've got a smaller PSU on hand for an external SCSI enclosure that wil fit just great. I've already tested it to make sure it comes up even without a load, so no problems in getting it started there.

I'm still a little confused, though. I was pretty sure that the 630 supply wouldn't come up no matter what without the ADB trigger. I've seen that these have been used in CC/Takky mods before, so I'm curious how those people get them started. Is this understanding wrong? Does the 630 PSU not need an ADB trigger?

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Drew

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You [b]might[/b] get away wit

You might get away with the CC's own PSU, however depending on the logic board, you may need 3.3V from a second PSU (unless you use a regulator instead).

I recall someone mentioning long ago that while it may be possible to drive a lot from the CC's analog board, the additional strain may shorten the board's lifespan.

edit:I did rediscover John Stocker's page, as well as Chris's FAQ, and both mention the 630 supply being triggered from a relay.

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You will definitively need the additional PSU

Greetings!

When I built my 6500 Takky I've tried to get away without the additional PSU at first. It will somewhat function without it, but there are several limitations that come with it. The 6500 board will run without the regulator, but if you want to use the cache card or i.e. a G3 CPU Upgrade card, you will need the additional 3.3V supply. The system will not start up if these are installed and you don't have the 3.3V. Also, what I've noticed is without additional power hooked to the logic board, the physical strain is noticable. I had white lines running across my screen and when the hard disk was accessed, the screen would slightly dim and flicker. The same with network activity. Therefore, I would really recommend to wire in the additional PSU! After I installed one in my Takky, all these problems disappeared and the screen refreshes smoothly without any problems.

Cheers!

BeniD82

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2nd PSU

Of course, I do intend to use a 2nd PSU. I have two confusing points:

1) How can you start a 630 PSU by relay if it isn't connected to ADB?!
2) Are the 5V and 12V supplies from the analog board enough for a fully equiped PCI logic board?

Note that neither question pertains to the 3.3V supply or to hard drives. I plan on running those off a second PSU. Depending on the answer to question 1, that PSU may be a 630 PSU which is definitely strong enough (overkill, even) for one HD and the 3.3V supply.

Thanks for all the help so far! The CC community is awesome! John Stalker's page is where I got the idea of running the logic board off the 630 PSU. Maybe I'll just email him directly...

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Drew

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People have used generic PSUs . . .

. . . that way there are no 'turn on' issues - you just turn on from a relay from the a/b supply.

I generated 3.3v from the a/b's 5v line, and my Takky ran without an extra PSU. But I had no extra PCI cards, apart from the cache card.

Stuart

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John Stocker

So John Stocker's email address bounces. Go figure.

But a closer reading of his website indicates that he left the ADB lines to the 630 PSU intact from the wiring harness and didn't connect them to the CC analog board.

"http://glowsoft.com/sfs/pcc/" wrote:

The new motherboard and all it's components actually runs off a Quadra 630 power supply mounted next to the display tube (see picture of innards). The ADB power lines are connected to this additional power supply, and the old Classic power supply is activated by a 12V relay upon pressing the power key. The Quadra 630 power supply just barely fit when I reworked the back of the case and reset the cooling fan.

But the CC has a pseudo-soft power PSU. Doesn't it need the ADB signals active to power up and light the CRT or does it always apply voltage to the CRT so long as the power switch is on? Anybody know? It seems like whenever I flick the switch on the PSU, I hear the CRT charge up. So I'm guessing that the A/B always applies power to the CRT if the switch is in the "ON" position... That could be handy.

Next question: Is a 6400/6500 PSU the same size and shape as a 630 PSU? Wink

Peace,
Drew

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Re: Takky power supply question

alk wrote:

The 630 supply is a soft-power switched supply. So it needs an ADB pin shorted to ground to start, right? How do all you geniouses get your 630 supplies to power up when the 630 PSU isn't connected to your Mac's ADB lines?

I tried shorting the ADB power sense line to ground on the 630 PSU, but that didn't do anything.

Can you all help? I can't figure out how to jump start my 630 PSU. And if I can't get it working now, I can't imagine how I'll get it working with a relay.

I've been contemplating putting my Mac Mini into a new case, and I have an old Quadra 630 laying around that seems suitable. So I've been searching for how to activate the 630's PSU like you have.

Anyway, after being unable to find an answer, I decided to just... experiment. Seems like shorting pins 3 and 5 does the trick (pin 1 being the closest to the edge to the circuit board, and 6 being next to the fan connector).