My Macintosh Quadra 700 Clean Up and Fixes

[jmacz]

Over the past few weeks, I have gotten a lot of value out of this forum, just looking at the archive of helpful information. I decided to return the favor by documenting some of the work I have done to my Quadra 700 recently.

Here she is:




Exterior Cosmetics

• The Quadra 700 casing had some cracks / chunks missing from it when I purchased it. I unfortunately do not have the before picture but it was awful and the case was also very yellowed from aging. Likewise, the AppleColor High Resolution RGB Monitor (M0401) also had a crack on the front bezel and pits on some of the edges.
• Fix: I took JB PlasticWeld and filled in the cracks. I also used it to remold the chunks that were missing in the Quadra 700 case. You let it harden a bit until it gets tacky and then quickly mold it into shape and let it cure. After it was completely cured (over 24 hours), I used various files to sand it back into shape so that it fit in with the surrounding parts of the case. As you can see above, you can't see where the cracks and missing chunks were.
• Paint: Sorry to the purists... with the case work done, there was no way I could use retrobrite methods to remove the yellowing since there was plastic weld work done. So I had to go for paint. In particular, I used Rustoleum Satin Stone Gray spray paint. The satin mirrors the shine from the original plastic. The stone gray is off a bit from the original color - it's both slightly cooler in color temperature as well as slightly darker. You can compare it in the picture above with the Apple Extended Keyboard II which is the original non-yellowed color. But it was close enough and I didn't want to try to source custom spray paint matching the Pantone color that is floating around the Internet for what Apple used. It was good enough for me and looks great. Note that I fully disassembled both the Quadra 700 and the monitor before painting. And I let the paint cure for 5 days.
• What about the Apple logos? I used liquid mask. You brush it onto the Apple logo, the LED lights, and it dries as a mask you can later peel off. After spray painting, I peeled off the mask.
• What about the Macintosh Quadra 700 logo? Yeah, nothing I could do about this one. The spray paint obviously covered up the original silk screened model name. I had measured ahead of time the size of the logo and the position of it. Then to replace it, I used a water transfer decal. I purchased Koala Waterslide Decal Paper from Amazon. There are versions of this for both laser and inkjet. I used laser. I then sprayed some clear coat paint on top of it to preserve the decal. Then it was just transferring the decal to the case. For the font, I found Adobe Garamond Condensed online. It was still not condensed enough so I scaled the width down a bit before printing.
• Disassembly and Maintenance Doc for the Monitor: Repair Manual

Upgrades to Memory

• Found a vendor selling 30 pin 16MB SIMMs on eBay and so purchased four of them to upgrade the Quadra 700 from 20 MB (when I bought it) to 68 MB. It was pretty cheap. Of course I have 4 x 4MB sitting around now but oh well.

ATX Power Supply Conversion

• My Quadra 700 had an Astec power supply in it. It made some funky noises from time to time so I decided to replace it with an ATX conversion. The trick here was to find a PSU with the appropriate current on the -12V line as well as small enough to fit inside the existing metal PSU enclosure.
• Donor PSU: I purchased the Logisys Micro ATX 350W Power Supply from Amazon. It was small and fit all the specs.
• Wiring it up was pretty straightforward using the information found on this forum (links below).
• I reused the power port from the original Astec, so had to rewire that but it was easy.
• The only thing I could not get working unfortunately was the additional power port on the Astec (for connecting a monitor's power, etc). There was soft power circuitry on that power port so that it only delivers power when the CPU is on but I didn't bother figuring out how it works or how to wire it. I also don't think I had room to fit it inside the case. So I punted. That second port is wired up but it delivers power all the time which is not correct.
• New Fan: I also took the time to replace the fan with a Noctua NF-A8 80mm Fan. Note that mine came with 4 pins while the PSUs is expecting the normal 2 pins. I used the yellow/black wires and attached it to the original fan plug/wire that came with the Logisys PSU.
• For the soft power, I followed the documentation in the links below. I used a 2N2222 NPN transistor.
• Links: Eric Bylenga's ATX Conversion and Demi's ATX Conversion.

SuperDrive Floppy Rebuild

• My Quadra 700 came with a Sony MP-F75W-11G floppy drive. It wasn't working.
• I disassembled and completely cleaned and re-greased all the parts. But the drive had the usual issue where the one yellow eject gear completely disintegrated. After replacing it, the drive is working great.
• Replaced Eject Gear: I got replacement gears off of eBay which worked fine.
• Links: Adrian's Floppy Rebuild Video

PRAM Battery

• Luckily the Quadra 700 I got didn't have an issue with the PRAM battery. But I wanted to replace it.
• Picked up a meowToast CR2032 to 1/2 AA adapter which allows you to use common 2032 batteries instead.
• Links: meowToast

SCSI Drive

• My Quadra 700 came with a working Quantum 240MB (?) internal drive. But it also was making some strange noises so I decided to replace it with a flash card solution. I went with the ZuluSCSI 1.1 and a 32GB SD card. I've got 3 "drives" now, all are 2GB in size, all from this one SD card.
• I also added a 2 pin header to the ZuluSCSI to allow for the drive light and put together a quick LED for it (goes into the original drive light in the case).
• Links: ZuluSCSI and purchased it here Rabbit Hole Computing

AppleTalk/PhoneNet Connector

• I wanted to connect the Quadra 700 with another Mac I have via AppleTalk. I found a used Farallon PhoneNet connector on eBay. Problem is that it didn't come with the necessary termination plug. You can build them. Just requires you to get a 120 ohm 1/4 watt resistor. You get a RJ11 connector plug and bridge the 1st and 4th pins using the resistor. Simple.

Ok, some additional pictures. I wish I had more but I wasn't thinking of documenting when I got started so I apologize.



The above is a close up of the Quadra case. The upper left corner in the picture was cracked and a chunk was missing. The rebuilt corner looks ok Also you can see that the Macintosh Quadra 700 is a waterslide decal. But not bad from a grossly yellowed case with cracks and missing chunks. Same with the monitor front bezel.



The above is the meowToast adaptor for the PRAM battery.



The above is the custom termination plug for the PhoneNet adapter.



Original Astec power supply next to the donor Logisys PSU.



Wired up with the Noctua fan and sitting inside the old Astec casing.



Another view. On the right side lower corner is a small board with the soft power transistor work.



Reassembled. Can't tell from the outside that it was modified.

 

[bakkus]

VERY nice job!

 

[thecroc15]

WOW!! Another one saved!

 

[pizzigri]

Hi there! I wanted to replicate the ATX conversion, however, I could not source ANY ATX psu with a rated -12v of over 0.5A, plus, none have a +5v continuous of a few milliamps, they're all above the 2A mark... and I wanted to ask if anyone is able to point me in a good direction and /or help me out. I am located in EU (Italy to be exact)....
all my best - and jmacz, great work here.

 

[cheesestraws]

Oh, well done. What a nice result you've got there.

 

[3lectr1cPPC]

Great job with the paint, it matches platinum quite well! Looks really nice. I’d be able to tell that it had been repainted due to the decal but I’d never know that a whole chunk of the case had been missing, you got that fixed up well! Should last for years to come.

 

[jmacz]

Hi there! I wanted to replicate the ATX conversion, however, I could not source ANY ATX psu with a rated -12v of over 0.5A, plus, none have a +5v continuous of a few milliamps, they're all above the 2A mark... and I wanted to ask if anyone is able to point me in a good direction and /or help me out. I am located in EU (Italy to be exact)....
all my best - and jmacz, great work here.

Yeah, most of the ATX/SFX PSUs I saw didn't have enough amps on the -12v line, and the ones that did were too big to fit into the original PSU's casing. I finally found the one I used which had 0.8A on the -12V line like Eric's in his blog post. Regarding the +5V, I did not see a single ATX PSU with a low current on that line. Mine had 2A. The Seasonic PSUs that others on this forum used also had 2A on that line. So that's what I ended up using.

 

[bakkus]

Hi there! I wanted to replicate the ATX conversion, however, I could not source ANY ATX psu with a rated -12v of over 0.5A, plus, none have a +5v continuous of a few milliamps, they're all above the 2A mark... and I wanted to ask if anyone is able to point me in a good direction and /or help me out. I am located in EU (Italy to be exact)....
all my best - and jmacz, great work here.

For my Q700 ATX-conversion I used a Seasonic SS-250SFD MicroATX.
They can still be found on eBay and similar sites.
All rails should be within specs, and it easily fits into the original PSU with room to spare.
I even hooked up a new Noctua fan to the original fan-out on the Seasonic so it is controlled by temperature.

 

[pizzigri]

Jmacz and Bakkus, OK - so I found this: https://www.ebay.it/itm/373632039064 price is OK, and the psu is exactly as the ones described!
Thank you guys much appreciated!

 

[jmacz]

VERY nice job!

WOW!! Another one saved!

Oh, well done. What a nice result you've got there.

Thanks guys.

Great job with the paint, it matches platinum quite well! Looks really nice. I’d be able to tell that it had been repainted due to the decal but I’d never know that a whole chunk of the case had been missing, you got that fixed up well! Should last for years to come.

One of these days I will invest in a laser cutter and if so, maybe I can make a mask which I can then use to spray the model identifier on the case. That way it's not as obvious it's a decal.

 

[jmacz]

Jmacz and Bakkus, OK - so I found this: https://www.ebay.it/itm/373632039064 price is OK, and the psu is exactly as the ones described!
Thank you guys much appreciated!

Goodluck!

 

[aeberbach]

Beautiful job, I would not have picked that the color was not quite perfect. Is there a video or blog illustrating that JB Weld technique for old case repair?

 

[jmacz]

Beautiful job, I would not have picked that the color was not quite perfect. Is there a video or blog illustrating that JB Weld technique for old case repair?

I just searched and here's one showing the concept in use to repair a body panel on a motor bike. It basically is like using putty and you mold it into shape, or you can fill cracks with it, and once dry, you can sand or carve it, to blend in perfectly. This person didn't do the fine sanding work to get it perfect but you get the general idea:

 

[jmacz]

Regarding the spray paint, you want to take multiple very light coats with a 5 minute pause in between. This ensures you don't get a paint run which will ruin everything. And the added bonus with spray paint is that if you don't sand/polish it afterwards (which I purposely did not do), you get this very very slight texture which matches the texture that was on the original case. So even with the plastic weld work (which comes out smooth because of the sanding), you get the texture back and it matches the rest of the case.

 

[paws]

This is beautiful work, and a great write-up, too. Thank you so much. I also have one with a PSU that needs to be fixed.

 

[jmacz]

My next project... trying to reproduce some hard disk noises since the SD card is silent. Started a thread here:

Miniscribe 8425S Sound Reproduction

My Quadra 700 is running off of a ZuluSCSI 1.1 and that works great but I definitely miss the noises from a physical hard drive. Specifically, I miss the crazy noises from the Miniscribe 8425S 20MB hard disk I had in my Macintosh SE back in the day. I first thought of developing an extension...

68kmla.org

 

[jmacz]

Found an issue today that will require some debugging.

Quadra 700 hangs on boot or randomly hangs with nubus cards.

Primarily been using my Quadra 700 with its on board video and it's been pretty stable. I have not really had the nubus slots populated but in the past few weeks, I've been trying it out with my Spectrum 24/III card for brief periods of time (no longer than 15-30 minutes at a time). Today after a reboot, my Quadra would chime but not get to the first gray screen. I took the Spectrum 24/III out and put it into my IIci and it works fine there, so the card seems fine.

Then tried the following in the Quadra:

• With Spectrum 24/III - again, stuck before first gray screen.
• Removed Spectrum and tried with onboard video - no problem, boots fine.
• With Spectrum 24/III - again, stuck before first gray screen (and happens on either Nubus slot).
• Removed Spectrum and tried with E-Machines 8bit card - this time shows the gray screen but no happy mac screen, just stuck on gray.
• Removed E-Machines and tried with onboard video - again, no problem.
• Tried E-Machines 8bit card on both slots - gray screen but no happy mac screen.
• Tried Radius 8bit card on both slots - boots but after running for a few minutes, system freezes (no cursor response).
• Removed all cards and tried with onboard video - again, no issues, boots fine, no hangs (for hours).

I tried all the above nubus video cards in my IIci and no issues in my IIci.

I'm guessing something's wrong with the nubus on my Quadra 700.

The other problems I have had with this Quadra in the past few months:

• Did not detect SCSI drive (ZuluSCSI RP2040) when 16" Display connected to onboard video - this problem would come from time to time and only go away when I reset the PRAM. So stopped using the 16" and went back to a 13" Apple RGB and no issues.
• Random crashes after startup with ZuluSCSI RP2040 - I would get weird issues including crashes, no disk detection, error saying some files were missing (even though they were there). This was limited to the RP2040. When I use a ZuluSCSI 1.1, never see these issues.

 

[pizzigri]

Dunno, did you check the PSU? Maybe it’s failing and the power is just enough for the LB itself but not enough for ay Nubus cards in the system.

 

[jmacz]

Dunno, did you check the PSU? Maybe it’s failing and the power is just enough for the LB itself but not enough for ay Nubus cards in the system.

Good thought. Unfortunately, I tried 3 different PSUs in it and same result. Two of the PSUs were converted ATX ones, one was a stock GE.

 

[jmacz]

Sequence:

1. Power button hit on keyboard
2. Startup chime plays
3. No video yet on both the onboard video as well as the E-machines card installed in the Nubus slot.
4. Should be checking the memory at this point and takes a while since the machine has 68MB of memory.
5. You hear a slight static noise on the speaker which I normally hear right before the video goes on (after memory check succeeds).
6. Monitor connected to onboard video starts display video (gray screen).
7. Monitor connected to e-machines doesn't show anything (still black, no signal). Normally should show e-machines logo splash screen.
8. Stuck here and won't make further progress. It gets stuck here if I have this e-machines card in either Nubus slot (and again, the card works perfectly in my other Macs).

I think something's getting hosed during the initialization of the Slot Manager maybe? Documentation suggests the gray screen comes up for video cards during the initialization of the Slot Manager, but is this just for nubus cards? I'm not sure when onboard video is initialized, before or after the Slot Manager?

I don't believe it gets to System Startup since it should be looking for an active disk at that point. I've unplugged all my drives so I should be getting a question mark disk icon but it never gets there.