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Quadra 950 squeaking noise and distorted video

ktkm

Well-known member
I’m testing a Quadra 950 in the hope of adding it to my collection. But it makes a subtle squeaking noise (not from the speaker), and the internal video becomes distorted when it reads from the hard drive. If I push down the mouse button, for instance, to make a selection in the main menu in finder, it is almost like I can control the squeaking noise. If I use a Nubus graphics card, the video is fine, but the noise persists. On close inspection, the board looks very nice and clean. Has anyone here had a similar problem?

 
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ktkm

Well-known member
Here’s a demonstration

ma0f9vj.mp4


 
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ktkm

Well-known member
The distorted video disappeared when I added an extra SCSI hard drive to the chain. Could it perhaps have something to do with the SCSI2SD 5.1 I’m using? The subtle sqeaking noise is still there though. Well, I suppose I’ll have to keep digging …

 

Bolle

Well-known member
Not sure how the regulation in the 950 PSU works... but it’s possible that added load on the 12V line could smooth things out.

My WGS95 does the same thing - jiggly video and squeaky sounds, actually I can’t remember right now if my Q950 does it as well.

I am running real hard drives in both of them though.

Stock PSUs on both, not yet recapped. (and I don’t plan to, may as well go ATX right away)

 

BadGoldEagle

Well-known member
Oh hi there. Did someone mention ATX and Quadras?  :)

When I first saw this topic I immediately started suspecting the PSU. The Delta units in Q900-950/WGS95-9150s have technically two separate 12V rails. Since there's only one pin on the logicboard for 12V, I'd suspect the other one is for the hard drives/accessories. I know the SE/30 uses 12V for video, no idea if the Quadra does as well but I doubt it. I would have thought the 12v rails were isolated but perhaps not... One issue on one rail could have an incidence on another though.

I've found that recapping those beasts is extremely expensive, time consuming and probably useless anyway. I think some other component fails and kills them, but which one? Without a schematic it's really not easy to diagnose. That's why I went the ATX route. 

 
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ktkm

Well-known member
@Bolle and @BadGoldEagle! I’m so glad you joined! I’m intrigued by the whole ATX thing. @BadGoldEagle I’ve been following your project, it actually made me consider the Quadra 950 in the first place, and now I’m in love with the beast. And after taking the PSU apart, for a good clean, understand what you both are talking about, its a tad too much to handle, at least for me. If I decide to take the ATX path, where do I start? And @BadGoldEagle how is your project coming along, what’s the latest news? @Bolle do you use an ATX in any other machine?

I’d love to hear more!

 

BadGoldEagle

Well-known member
I’ve been following your project, it actually made me consider the Quadra 950 in the first place,
Well I'm both happy and sorry for you! The key (being a car guy), the speed (being my first 040) and the expandability is what drew me to the 950. But it's plagued with reliability problems. Hopefully an ATX PSU will solve most of them. It also can suffer from Maxell explosions, being manufactured during that time frame. Tantalums on the logic board can also go bad and explode... 

I also find that it's a shame that Apple didn't upgrade the controller to support SCSI2 fast speeds... Apart from that, it's easily overclockable to 40MHz, it's got great built in video, can have up to 256MB of RAM and has an upgradable ROM (compatible mechanically with that of the SE/30 and I already found a hacked image with a disabled RAM check online!). Mine has 256MB now and it's slow! 

And after taking the PSU apart, for a good clean
Oddly enough, I think this can cause more harm than good. But I can't stand bringing home someone else's 30 year old dust so I HAVE to thoroughly clean every thing I buy second hand (mostly Macs).

If I decide to take the ATX path, where do I start? And @BadGoldEagle how is your project coming along, what’s the latest news?
If you're in a big hurry or if you don't need a working monitor plug, hard drive connectors or a temperature controlled fan, you can go ahead and do the Geekdot mod. If you want a quick and dirty way to power up your Quadra, you can buy a 24-pin ATX extension cable and rewire it accordingly. You'll lose soft power but it's a great way to check that everything is fine and it's really easy, you just need staples. 

I just posted about my mod. It's going along really well but I still have triple check everything before I send you guys kits, so I need a couple more months. I'll also write some instructions and provide a template for the drilling if you want to use the same PSU.

The big issue with the ATX mod is that it's getting really difficult to find modern PSUs that match the original's specs. Depending on what you're going to do with your Quadra, a PSU with a 20/25A 5V rail may be sufficient if you don't chuck it full of hard drives/expansion cards. The Bicker BEA 630 matches almost exactly the original specs and doesn't really need a fan.  I also just watched LTT's latest PSU video about the new ATX12VO standard. I hope it won't be universally adopted. 

 

ktkm

Well-known member
Squeaky noise solved (I think). I switched out the extremely large 80ns SIMM:s it came with, to low profile 70ns. Could energy consumption be an issue regarding squeaky memory? Everything seems more reliable now, the energy saver init, that said it didn’t work with the computer model before the switch, is working now.

It also can suffer from Maxell explosions, being manufactured during that time frame. Tantalums on the logic board can also go bad and explode... 
Yes, been there! The Quadra, however, came with a nice and blue ’Sonnenschein’ from 1992 that looks as if it was made yesterday.

I also find that it's a shame that Apple didn't upgrade the controller to support SCSI2 fast speeds... Apart from that, it's easily overclockable to 40MHz, it's got great built in video, can have up to 256MB of RAM and has an upgradable ROM (compatible mechanically with that of the SE/30 and I already found a hacked image with a disabled RAM check online!). Mine has 256MB now and it's slow! 
Yes, its a shame, but I was thinking of putting Jackhammer in it to see if I could get some better disk performance.

If you're in a big hurry or if you don't need a working monitor plug, hard drive connectors or a temperature controlled fan, you can go ahead and do the Geekdot mod. If you want a quick and dirty way to power up your Quadra, you can buy a 24-pin ATX extension cable and rewire it accordingly. You'll lose soft power but it's a great way to check that everything is fine and it's really easy, you just need staples. 
Since I’ve solved the noise part I’m not in any hurry to get the ATX mod. I rather go for something that lasts.

I just posted about my mod. It's going along really well but I still have triple check everything before I send you guys kits, so I need a couple more months. I'll also write some instructions and provide a template for the drilling if you want to use the same PSU.
Just got read-up, nice! Put me down for one when you’re ready! :)  

The big issue with the ATX mod is that it's getting really difficult to find modern PSUs that match the original's specs. Depending on what you're going to do with your Quadra, a PSU with a 20/25A 5V rail may be sufficient if you don't chuck it full of hard drives/expansion cards. The Bicker BEA 630 matches almost exactly the original specs and doesn't really need a fan.  I also just watched LTT's latest PSU video about the new ATX12VO standard. I hope it won't be universally adopted. 
Well, I’d really want to keep my options open. Are you going for the Bicker 630? Maby I should order one when they are back in stock?

Thank you so much! :)  

 

BadGoldEagle

Well-known member
Good to hear you fixed the squeaking noise and that it was just bad RAM. If you can live with spinning rust, then you're all sorted for now. 

The next project will involve building a fake PRAM battery and a support that can be fixed to the outer casing using the security slot. If I could get my hands on a Mac security kit, this would be only a matter of a few hours to design with CAD. 

That way we could keep our PRAM settings without risking battery leaks...

Are you going for the Bicker 630? Maby I should order one when they are back in stock?
Any PSU will do actually. The Bicker was an industrial unit and is getting old and expensive (I got mine for cheap at 50 euros). A second hand Corsair VX550W will also work (it's older and weaker than the Bicker, but more readily available and usually cheaper). There aren't that many modern PSUs with strong 5V rails anymore I'm afraid...

 

ktkm

Well-known member
The next project will involve building a fake PRAM battery and a support that can be fixed to the outer casing using the security slot. If I could get my hands on a Mac security kit, this would be only a matter of a few hours to design with CAD. 

That way we could keep our PRAM settings without risking battery leaks...
Sounds like a useful device now with more batteries to keep track off. I’m starting to understand @Bolle:s straight-edge approach of keeping batteries out, every time I bring home a new old Mac.

Regarding PSU, I found this one: 

https://www.ebay.com/itm/Replacement-Power-Supply-AT-for-FSP-SPARKLE-SPI-250G-SPI-250G-B-300-Watt-Upgrade/282705613954?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

Would that do?

 

Sir Foxx

Well-known member
Also want to chime in. My q950 also makes weird squeak(?)ing noises when the computer is doing something. HDD activity, mouse inputs, etc. It reminds me more of the sound that the natural gas line made in my parents old house when anything was using the gas. Onboard video also has a fuzziness to it, but the external graphics does not. I'd be down to recap my psu, but I havent had luck trying to unfold the case halves to get access to the internals. I also accidentally burned out the fan controller when I first got it, and would like to fix it instead of using a plug on the underside for the fan.

I also find that it's a shame that Apple didn't upgrade the controller to support SCSI2 fast speeds... Apart from that, it's easily overclockable to 40MHz, it's got great built in video, can have up to 256MB of RAM and has an upgradable ROM (compatible mechanically with that of the SE/30 and I already found a hacked image with a disabled RAM check online!). Mine has 256MB now and it's slow! 
Do you have a link? I also have 256mb ram and the inital boot time is unbearable haha

 

BadGoldEagle

Well-known member
It's an AT PSU, not an ATX one. Specs-wise it's fine but you need to get an adapter and you'll probably lose Softpower.

I don't remember how the AT power switch is wired up, but it probably doesn't use ground. 

Do you have a link? I also have 256mb ram and the inital boot time is unbearable haha
http://www.synack.net/~bbraun/macsrc/Quadra-900-mod.rom

I can't find the page that explains the changes between this and the original one. But it should have RAM and ROM checks disabled.

512KB SIMMs (SE/30 IIsi IIfx...) are too small for this ROM. This one should work: https://www.ebay.com/itm/GGLABS-2MB-MACSIMM-MAC-SE-30-IIsi-IIfx-flash-ROM-SIMM-64pin-Apple-ROMDISK/401442364985

You can even ask the seller to flash the ROM for you...

 
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ktkm

Well-known member
It's an AT PSU, not an ATX one. Specs-wise it's fine but you need to get an adapter and you'll probably lose Softpower.

I don't remember how the AT power switch is wired up, but it probably doesn't use ground. 
Well, too bad. At least the price felt right. ;-)  

 
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