Performa 6200 and 5400 Mother Board.

[gpbonneau]

Hello,

I was given a PowerMac 5400, all plastic case are broken (may be it fell...) but it still works

I already have two Performa 6200, one works well but an other without mother board (battery leak).

My first idea was to put the 5400 MoBo in the 6200 case (same size, same connector), but that don't works :-(

It power on (fan run), but that's all, no hard drive, no startup sound,  no video ...

When I put back the MoBo in the 5400 case all works well. Same with the 6200 which works well with its MoBo.

No way to use a 5400 MoBo in a 6200 case ?

 

[waynestewart]

I believe the issue is that the 5400 MB requires 3.3 volts for the RAM. That was an issue for people using the 5400 MB in the Color Classic. Take a look at one of the Color Classic Takky upgrade sites for a solution

 

[Trash80toHP_Mini]

3.3V would be for the PCI slot, there have been reports of the 5400/6400 boards running fine without a PCI card in the slot. You can definitely get it running the the 6200 case. ISTR it's not all that difficult, but then again I haven't gotten around trying it. My 6400 re-case included the stock PSU.

Search "frogeye" here to find the PowerCC diagram referenced in just about any wiring loom related thread we've had. The 3.3V hack has been done on several occasions and it seems be be getting easier and easier with every revision.

 

[gpbonneau]

It's strange in fact. I have also a 5500 (with a Crescendo G3/400 L2) :



When I put the 5500 MB in the 6200 case, it works fine !!

When I put the 5400 MB in the 5500 case, it works fine too, but not in the 6200 case  8-o

I think it's a problem with the 5400 MB, but I don't know why...

The MB is not so clean, there are some traces of leak (battery or capacitor ?) :

 

[Trash80toHP_Mini]

Some of that's standard behavior.

LaPorta mentioned trouble in crossing what I've been thinking of as a "6200 barrier" in the process of his Quadra 630 build with a PPC board in the Quadra harness or the other way around with a 630 board in an Alchemy or Gossamer harness?

Only the 6360/6400/5400 Alchemy architecture boards require external 3/3V input from the PSU. One of the few things Apple got right when they transitioned to the 50MHZ system bus 5500/6500/TAM Gazelle architecture was to put the 3.3V regulator for PCI on the logic board. We likely have the ridiculous Power Supply setup of the TAM to thank for that. One less finicky DC voltage over a relatively long distance for DC power transmission is a good thing.

I'm wondering where the line might be drawn between models or if the barrier might be situational rather than a basic incompatibility? I have my 6290 and 6500 boards running in the 6400 BenchMac chassis, but I can't find my Quadra 630 board for testing. :-/

edit: Love that AIO in Ninja garb. One of those is in the Industrial Design collection at MoMA.

 

[gpbonneau]

Thank you for your help, it was indeed a problem with the 3.3v missing from the PSU.

With the information from powercc.org/takky/, I added a 3.3v regulator directly in the PSU.

I added a wire in the connector at the free place (PSU side. Harness side the wire was already in place), and a TSR 1-2433 from TracoPower.

The 5400 MB now works fine in the 6200 case, very well 

Before and after :

  

Last question : I did not dare to put back a 6200 MB in the case to test... it is a problem with the 3.3v now in place ?