Q700 modification

[crazyben]

Hi guys,
I recently picked up 2 q700. Both do not have boot chime or video. Upon closer inspection I see some modifications.

On 1st the oscillator was removed and there is plastic on top of it (pic 1). Does the oscillator (pic 2,3) with bent pin go in there? There is oscillator tied to PSU (pic 4). I am guess that is the stock one.

On 2nd CPU was upgraded. When I pulled the board I noticed that metal part was loose (pic8). Also upon closer inspection I see two pins missing on bottom left corner (pic 6)
First 4 pictures are from 1st q700 and last 4 are from 2nd one.

 

[Phipli]

Hi guys,
I recently picked up 2 q700. Both do not have boot chime or video. Upon closer inspection I see some modifications.

On 1st the oscillator was removed and there is plastic on top of it (pic 1). Does the oscillator (pic 2,3) with bent pin go in there? There is oscillator tied to PSU (pic 4). I am guess that is the stock one.

On 2nd CPU was upgraded. When I pulled the board I noticed that metal part was loose (pic8). Also upon closer inspection I see two pins missing on bottom left corner (pic 6)
First 4 pictures are from 1st q700 and last 4 are from 2nd one.

Nice stuff. The first one is overclocked to 32.5MHz. straighten the pins in the clock and plug it back in. Pin one is usually marked by a pointy corner and the other three corners are rounded. Pin one goes where there is a notch in one d of the silkscreen on the board where the socket is (towards the CPU I believe).

The second is likely a Quad Doubler or similar, likely letting that machine run at 50MHz! Very worth repairing. Check the CPU socket for the broken off pins.

 

[Phipli]

That last picture it looks like the parts have sadly been bouncing around inside the case. Hopefully they haven't caused too much damage. That crystal needs soldering back onto its footprint that you've shown it next to shouldn't be too difficult though I anticipate that is the crystal for the real time clock.

 

[crazyben]

Nice stuff. The first one is overclocked to 32.5MHz. straighten the pins in the clock and plug it back in. Pin one is usually marked by a pointy corner and the other three corners are rounded. Pin one goes where there is a notch in one d of the silkscreen on the board where the socket is (towards the CPU I believe).

The second is likely a Quad Doubler or similar, likely letting that machine run at 50MHz! Very worth repairing. Check the CPU socket for the broken off pins.

Like this?
I found the broken pin in the socket. Do I need to resolder them?

 

[crazyben]

That last picture it looks like the parts have sadly been bouncing around inside the case. Hopefully they haven't caused too much damage. That crystal needs soldering back onto its footprint that you've shown it next to shouldn't be too difficult though I anticipate that is the crystal for the real time clock.

I don’t think it moved moved. The cpu board was holding it in there. I can solder it back on. Is the broken pins in the cpu board cause of concern?

 

[Phipli]

Is the broken pins in the cpu board cause of concern?

Short answer is yes, without going and working out exactly what pins they are, but it should be repairable.

 

[Phipli]

Like this?
I found the broken pin in the socket. Do I need to resolder them?

They're not broken pins, I meant for the Quad Doubler board - the missing pins may be in the CPU socket it came from.

The one you have photographed there, those four corners are just the recepticals for the four pins on the clock that you need to put back in. It might boot once you put it back in (the right way around).

 

[crazyben]

So this is what I found. And looks similar to the pins on the CPU board. Am I safe to solder them back?

 

[crazyben]

They're not broken pins, I meant for the Quad Doubler board - the missing pins may be in the CPU socket it came from.

The one you have photographed there, those four corners are just the recepticals for the four pins on the clock that you need to put back in. It might boot once you put it back in (the right way around).

Sorry I got two replies mixed in one. I was referring to pins from from CPU board.

And I plugged the oscillator back and q700 is booting now with chime. I will find the working HDD to see what clock speed processor is on.

 

[Phipli]

And I plugged the oscillator back and q700 is booting now with chime. I will find the working HDD to see what clock speed processor is on.

Given the speed of the crystal, it can't be anything other than 32.5MHz, even if the OS reports something different.

Sometimes the OS rounds the number (or even misreports it on later computers).

 

[GRudolf94]

Sorry I got two replies mixed in one. I was referring to pins from from CPU board.

Attempting to re-solder those to the CPU speed-doubler will probably have a poor outcome. The missing corner pin is probably absent for keying reasons, one of them is TDO (test data out, part of the JTAG port and unused in the Mac), and the other is !IPEND, also unused. So don't bother "fixing" the CPU adapter.

 

[Phipli]

So this is what I found. And looks similar to the pins on the CPU board. Am I safe to solder them back?

Attempting to re-solder those to the CPU speed-doubler will probably have a poor outcome. The missing corner pin is probably absent for keying reasons, one of them is TDO (test data out, part of the JTAG port and unused in the Mac), and the other is !IPEND, also unused. So don't bother "fixing" the CPU adapter.

Good news.

I'd plug it in once very carefully, and never unplug it again if it works.

 

[crazyben]

Attempting to re-solder those to the CPU speed-doubler will probably have a poor outcome. The missing corner pin is probably absent for keying reasons, one of them is TDO (test data out, part of the JTAG port and unused in the Mac), and the other is !IPEND, also unused. So don't bother "fixing" the CPU adapter.

Sounds good. I was not getting chime or video before I pulled out the CPU card. Anything I need to check before I plug that back in and solder the crystal back?

 

[crazyben]

Looks like I have mini q950 . Thank you for your help @Phipli.

Now time for 2nd one to boot.

 

[Phipli]

Looks like I have mini q950 . Thank you for your help @Phipli.

Now time for 2nd one to boot.

Don't forget to turn 32bit addressing on

Edit - ah, 7.6.1 - it turns it on with a double boot. You're fine.

 

[crazyben]

Don't forget to turn 32bit addressing on

Edit - ah, 7.6.1 - it turns it on with a double boot. You're fine.

And guess what 2nd one booted with chime. Where do I check what kind of CPU upgrade is this. System profile showed below specs.

 

[Phipli]

And guess what 2nd one booted with chime. Where do I check what kind of CPU upgrade is this. System profile showed below specs.

Don't worry about it, it is probably a Sonnet or a Newer part, but I don't thing they need any software? So just use it.

You have one of the fastest 68k macs possible there. Run a benchmark. I doubt many people have a Quadra 700 faster than that. I can only think of one person, and that is because they overclocked the sort of card you have there.

It might or might not match an 840av, because the 840 has a much faster bus (you still have a 25MHz bus and memory).

Your FPU score will be through the roof though.

 

[crazyben]

I compared it with q950 and here is the results. I forgot about 840av. I can check with that if want to see it.

 

[crazyben]

Here compared to 840av.