I will be recieving a new (to me) PowerMac 7300/200. How do I turn it on?

[kkritsilas]

Hi,

I have recently bought a Centris 650 (you can see what I posted on it in the Mac II/Centris/Quadra section of the board). I was also able to locate a PowerMac 7300/200. It has a broken front panel power button, which I understand is pretty common to this generation of PowerMacs due to the brittle plastics used. Without the front panel power button, is there any way to turn on the power? I am thinking power button on an ADB keyboard, opening up the case and manually pushing a button, shorting a pair of pins, or like the Centris, a power button on the back panel?

I am going to need to get inside the machine, anyway, as I have zero details about its configuration (RAM, hard drive, VRAM, etc.). The machine says it is a 7300/200 on the front panel label, but that is about the extent of what I know. I did read up on it, and the base configuration is a 32MB RAM, 2GB SCSI hard drive, and 1MB VRAM. I really don't know if it is all there or not.

I'd appreciate any assistance. I'm going to open the machine up to see what is there, and if it is all there, I'd like to power it up and see if I at least get a start up chime.

 

[macuserman]

The power button on your keyboard should work just fine if the button on the machine is broken. No biggie.

 

[alectrona2988]

I used to have a 7300/200 and the power button along with several other plastic pieces fell apart. You would have to stick a screwdriver into where the power button used to be and you would have to find the actual button. Why apple didn't use a less convoluted way of power button placement is beyond me.

 

[cheesestraws]

Just use the power button on the keyboard .

 

[djhaloeight]

I believe there are 3D printed replacements available on eBay and whatnot. I think you can even get the files to print it yourself too. The button on my 7500 is missing as well, but I just use the keyboard power button.

 

[kkritsilas]

The PowerMac 7300/200 arrived today. It has its 12X Apple Mac CDROM drive, but no HD. The description was incorrect, it actually does power up, and following the previous posts here, I was able to turn it on from both the front panel power button, and from the power button on the power switch.

When turning it on, I did get a turn on chime (more of a gong) and spinning up sounds from the CD-ROM, but didn't get video output from the DB-15 connector (this has a DB-15 to HD-15 10 position switch adapter on it, going to a Dell Ultrasharp 2407). I'm pretty sure that this is a video resolution issue that the Dell Ultrasharp can't handle. Reason I say that is that the Dell seem to see the VGA cable connection, but it never locks onto the video signal. I know that the Setup works because I can get video output from a Centris 650, and got the floppy drive icon with the flashing question mark when I tried the Centris on it.

What I would like to do is remove the PRAM battery from the Power Mac, but can't seem to figure out how to get to the motherboard. I did take off the cover, and found that there is no hard drive, but the floppy and the CD-ROM are present. I also have a PCI network card installed in the Card bay, but cannot seem to figure our how to get to the motherboard, both to get to the PRAM battery, and to see what RAM and VRAM are present. Any help or tips on how to get to the motherboard would be welcome.

 

[Cory5412]

When you pull the top case off, near the left hand side of the drive area (but to the right of the slots) there should be latches at the front and back, position those toward the inside of the unit then pull up, I think there's a little handle of steel toward the middle. On the right-hand side (behind the CD drive but at the top) there may be a plastic foot, pull that out and the right-hand side of the machine should stand up on its own, however, that foot is one of the more delicate pieces at this point.

The motherboard will be there.

It's interesting that this machine has a PCI network card, in theory it's got onboard ethernet but it could ahve done specialized duty, be a faster card or the onboard may have died.


w/re video: how is the adapter set? Are all the pins to on or off or is it set to a specific mode?

UltraSharp 2407 should be able to display nearly anything a mac can output, maybe save for the 640x870 resolution used with the Portrait Display.

But, popping it open and pulling and reseating the CPU, RAM, and VRAM can't hurt!

I love the 7x00 series, so I'm rooting for this being an easy one to get going, good luck!

 

[Danamania]

This should help with the how to open, pointing to the latch Cory is referring to, also the 'foot' which is just a thin black plastic piece that slips into a supporting position when opened fully, but needs to be manually released or it'll just snap when you try to fold the drive bay parts down!

 

[Cory5412]

Thank you for these Dana!

I was thinking of the foot on the right at the top-right of the drive/power section, you can see it at the far right in the middle of the middle picture, but both of these feet are fragile and need consideration. as you're opening up a 7{2/3/5/6}00 or beige g3.

 

[kkritsilas]

Thanks for taking the time for posting the instructions.

I did get it open, and got the PRAM battery out. It looks like it hasn't leaked, and also looks like the factory original one, as it is purple and green, Tadiran brand.

After getting the drive framework out of the way, I looked the machine over, and it looks to have 4 16MB RAM modules, 2 VRAM modules (2 X1MB, I think). There is also some sort of module in the offset slot in the middle of the memory module slot group. I take this to be either a ROM module, or a cache module.

The adapter switches are set to 1,4,6,7 and 9 are on, the remainder are off. This is supposed to be the MultiSync mode, which is supposed to allow software selection of the resolution. With the PRAM battery out, it may reset the resolution settings, so I will try it again tomorrow (to let the PRAM bleed of any residual charge, so that it goes back to default). As noted, this worked on the C650 to generate a display on the same Dell Ultrasharp 2407. I am using the VGA port on the Ultrasharp.

The PCI network card is a 3Com 3C9008. I guess I will need to find drivers for the card, unless it is supported by any of the MacOS System releases natively. I don't even know if I want to use it, seeing as there is a built in ethernet port.

Plastics on the case seem really brittle. There were all sorts of broken plastic bits inside, various shapes of greyish white plastic floating around. I did get a hard drive sled with it, which seems to be intact and locks into place quite nicely. I don't know if the floppy is working yet, I will have to wait on resolution of the video output issue before I can test that, as I don't have any floppies to test with (although I have some blank ones on order, and a CDROM with System 7.6.1 on the way).

 

[kkritsilas]

some pictures of the 7300/200, because without pictures, it didn't happen (according to a lot of sites with message boards):

Unit with cover off:



Top down look at the machine:





A look into the card bay:



The PCI Ethernet card:



Is this a second SCSI connector (never seen two on a Mac before):



What are these slots for (I think the one circled in blue is a ROM/Cache card slot, and the one in red is a PDS slot?)


And finally, the DB-15 to HD-15 (VGA) adapter with the dip switch settings as I used with the Centris 650"\

 

[mdeverhart]

The slot circled in blue is the cache slot. The slot circled in red is a ROM slot. Here’s the service manual for the 7300 family:

https://www.applerepairmanuals.com/the_manuals_are_in_here/PM7300_7500_7600_WS7350.pdf

 

[kkritsilas]

mdeverhardt:

Thanks for the information on the slots, and the link to the service manual. I have downloaded it and will be referring to it often.

 

[mdeverhart]

No problem, happy to help!

 

[kkritsilas]

Update on the 7300/200. I managed to get video out of it by removing the old PRAM battery, waiting for a week, and then putting a new PRAM battery into it (I received battery that in my Centris 650). Its still not booting up, as I need a hard drive for it, but it is progress. I got a start up chime (gong more accurately), and got the standard black and white background with a floppy disk icon having a flashing question mark. I will be pursuing this further after I get a mouse and a SCSI drive of some sort.

 

[Cory5412]

That's great to hear, thank you for the update!