Mac IIcx vs. IIci PSU

[Markintosh]

Hey gang,

are the PSU’s of the IIcx & ci interchangeable?

the footprints seem the same & my gut tells me they are, but i wanted an expert opinion before i swap them.

Thanks!

 

[Sideburn]

Yes, IIcx IIci Centris Quadra 650 700, IIvx IIvi Performa 600 Power Mac 7100…

 

[Volvo242GT]

Hey gang,

are the PSU’s of the IIcx & ci interchangeable?

the footprints seem the same & my gut tells me they are, but i wanted an expert opinion before i swap them.

Thanks!

My IIci has a power supply from a Centris 650 installed. Works perfectly. Slightly higher wattage, since the 650 usually came with a CD-ROM drive installed.

 

[Markintosh]

That's good to know! Thanks gang!

 

[Markintosh]

Just put the GE PSU from the IIcx into the ci and it fired up! Mac-O-Meter says I have decent voltages.


Thanks again for the info

 

[Markintosh]

My 13" Apple RGB Hi-Res came in yesterday & I connected it to my Iici with the GE PSU. Mac & display powered up, but I have no HDD inside at the moment. Screen was RED.

Not very encouraging.

I then shut down, connected my 80SC and then: NOTHING. Like the PSU died.


The -12V pin spikes for a second when the power button is pressed, then falls to zero. Nothing on +12V or 5V



I had the 13" Display connected through the PSU. Perhaps this was too much for it to handle.


I only have one more PSU of that form factor from a 7200. I did not see it in the last of compatible models Above. Specs are CLOSE, but slightly different.

Here are the specs w/the model names typed over them:

Is it safe to install the Delta in my Iici even though some of the current specs are different? The GE & ASTEC have identical specs.

Thanks in advance.


-Mark

 

[Volvo242GT]

Think you might mean 7100... The 7200 uses a power supply with a harness, if I remember correctly. Yeah, the part number corresponds to a Centris 650 power supply, so that would've come from a 7100, not a 7200. So, you can just install it into your IIci. With respect to the monitor, I don't think that would've caused the power supply to die, unless it has an internal short somewhere, which is possible, due to it only showing red.

 

[Markintosh]

That's weird, I thought I replied to this-SORRY!

You are correct-I have a 7100! My buddy gave me this Mac years ago & I thought it was a 7200. Thank you!

The Delta is back in the 7100 & the HDD spins, no chime. No picture on tin Apple 13" RGB.

I don't have any RAM in the 4 slots. The board is supposed to have 8MB built in. System 7.5 is installed on the HDD, & I know the HDD works.

My logic board was destroyed by a battery & I have just replaced it today. The new board came with no RAM. One of my 72 pin SIMMs was destroyed by the battery, and I only had two SIMMs in the board.

Can a 7100 boot to 7.5 with only 8MB of RAM?

 

[Volvo242GT]

It should boot with 8MB of RAM. After all, 7.5 will boot on a Mac Plus with 4MB. The Nubus 601 machines do need four SIMMs, if RAM is added to the what's on the board, unlike the '030 and '040 machines, which can work with one 72-pin SIMM slot populated.

Re: the no startup issues, I think @3lectr1c is dealing with almost identical symptoms with a 7100 he picked up at the VCF East swap meet. So, maybe he'll chime in with any updates.

 

[3lectr1c]

Fixed mine with a logic board recap. I had an intermittent and sometimes broken chime and no boot/video. Works fine now after recapping the LB.

 

[Markintosh]

Thank you for your feedback! I was working with an untested logic board and monitor so I had no idea where to start.

A few moments ago I perused the bombed board and realized I had NOT PULLED THE ROM OFF IT~UGH!!

I pulled the ROM, installed it into the "new" board: CHIME! VIDEO! SYSTEM 7.5!

I can't believe I missed that! WOW!

know mine will need a recap, but fir now, getting it running was the most important.

Thank you both for your help just now!

-Mark

PS: I foind a seller on eBay with 4 32MB SIMM's, 60ns that are rebuilt. Price is pretty reasonable. I thin I'll max it out & fill up the VRAM & the Cache slot as well.

 

[Markintosh]

BTW: I found this an hour ago-these books are extremely helpful, for those who have not seen them. Apple Service Source Manuals. I have a few of these for other Apple devices.

PDF link for the 7100:

https://www.applerepairmanuals.com/the_manuals_are_in_here/Power_Macintosh_7100_Series.pdf