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Quadra 840v doesn't see any SCSI devices

epoxy2600

Member
Hi all, 

I'm trying to restore a Quadra 840av and am having SCSI issues. My fear is that the SCSI controller on the motherboard is fried and this computer cannot recognize any SCSI devices hooked to it internally or externally.

Here's the situation:

On power up, it chimes but the screen remains dark for almost 30 seconds (is that length normal?) and then it shows a grey screen with the cursor and the flashing "?" floppy icon. The cursor can be moved around with the mouse on that screen. So I am concluding that the Quadra has passed its initial diagnostics and now cannot find a System.

The computer came with 2x internal HDs: a Seagate ST1100N 1GB and a Quantum Lightning ProDrive 730 MB. I have confirmed that both work when hooked up to a PowerMac G3. But when hooked up either internally or externally to the Quadra they spin up but are not recognized.

I am able to boot with an "Install Disk 1" floppy that I made from the "Install Me First" System 7.1 Installer CD that came with the Quadra. The computer gives me a happy Mac, and then the installer software starts and I can navigate the first screens and click onscreen buttons, etc. However, since the Quadra fails to recognize a hard drive, I cannot proceed with installation and can only choose Cancel followed by Restart or Shutdown.

So the good: The Quadra can boot from floppy and the installer software seems to run fine suggesting the CPU, input/output and RAM are OK.
The bad: no combination of internal or external hard drives are recognized by the Quadra, and it seems like the internal CD-ROM is also ignored (when I try to boot from a System 7.6 Installer CD the Quadra still gives me a flashing "?" disk symbol).

I know SCSI is voodoo, so I've tried different combinations of SCSI ID numbers, termination on/off, termination power on/off on the two HDs, a different SCSI cable, hooking up internally vs externally and the computer still fails to see these HDs.

Is there something I just don't understand about the 840av SCSI? I've read the 660/840av models are particularly touchy when it comes to SCSI setup...?

Any advice would be GREATLY appreciated!

 

epoxy2600

Member
I should add that when I first got the 840av the board showed signs of leaky caps and the computer wouldn't even chime on startup. So I had it recapped, and now it lives but with the SCSI issues. I also installed brand new 128 MB of RAM thinking (hoping) that bad RAM was responsible.

Any suggestions? Or insights into 840av-specific SCSI weirdness I should know about?

Thanks!

 

bobo68

Well-known member
That does not sound good.

I just have the usual stuff to offer: did you zap the PRAM? Is the PRAM battery good?

In the Service Manual for the 840 AV there is a procedure to reset the logic board (http://tim.id.au/laptops/apple/legacy/quadra_840av.pdf).

1. Unplug power cable

2. Remove PRAm battery

3. Press Power-On button of the Mac

4. Wait for 5-10 mins

Maybe that helps.

 

Hotdog Zanzibar

Well-known member
The 128mb of RAM could be the culprit for the long delay at startup. Part of the startup procedure is a RAM check. The more RAM you have, the longer it takes to check. 

 

uniserver

Well-known member
the good news is you can install a scsi card.  if the onboard is dead due to cap goo rot.   

 

epoxy2600

Member
Thanks for the suggestions,

@bobo68: I installed a brand new PRAM battery (verified with meter it is putting out 3.6v). Also zapped PRAM at startup w/ comand-option-P-R several times and performed the mob reset procedure as you mentioned. No change.

@Hotdog: Yes, you are right the long black screen lag at boot up is indeed due to the 128 MB RAM installed - when I only have 32 MB in there it comes to life much faster. (I'm glad that is normal).

I was able to make a System 7.6 Disk Tools 1 floppy and boot from that. At least that gives me an active desktop. Interestingly, one time it gave me a dialogue box saying the internal HD was not recognized as a Macintosh format and asked me whether to initialize. The message suggested it was either improperly formatted OR it was protected by security software. (Is that a generic message?) I got very excited because at least it saw there was an HD! When I clicked "Yes" I saw the green access light on the HD light up, and I got the "Creating Directory" message, but it hung there for nearly 4 hours with the green light lit before I finally gave up and powered down.

When I hooked up the same HD externally to my G3 I was able to initialize it, which took only seconds (!) and I created a 1 GB Mac OS Standard partition and successfully wrote/read files to it and had Disk First Aid verify it looked OK. So I am sure the HD itself is good. I then used the System 7.1 Installer CD on my G3 to install a system to the HD before hooking it back up (tried both internally and externally) to the Quadra. No change: the Quadra still does not see it.

My last test was to take the HD from my Mac Iici that has a good bootable System 7.1 on it and hooked that up to the Quadra. Still no recognition at all.

So what I've concluded:

(1) The Quadra can see that HDs are connected to the internal and external SCSI busses, but it treats the drives as unrecognizable and fails to mount them.

(2) The CD-ROM drive behaves the same way. A known good external Apple CD300 drive acts the same - will either spit out the installer CD or tell me that the disk is unrecognizable and ask me whether I want to initialize it (which is strange to me since it is a CD).

(4) It's NOT a defective SCSI cable.

(5) It doesn't seem to be a termination issue since the HDs work with my IIci and G3 w/o messing with terminator power or jumpers. - But maybe the Quadra is THAT picky?

Here's another possible twist that I haven't explored yet but might be worth mentioning: The Quadra came with a National Instruments NB-GPIB-P Nubus IEEE 488 controller card installed. I had removed that and set it aside prior to recapping the mobo and then forgot all about it until just now. Is it possible that because the system was previously configured with this bus card, the SCSI busses now cannot function without it installed? I have to dig it out from storage to reinstall it, but if it is extremely unlikely this is reason then I won't bother.

@uniserver: yes I am tempted to install a Nubus SCSI card if the Quadra's native SCSI buses remain unusable. However, I'm not familiar with how such a card would be initially installed - would an ATTO or FWB card function as the sole SCSI bus, or do they depend on the computer booting from an alternate drive first to load up drivers before they become active?

Thank you all again for your input - this is a nice Quadra and I still can't rule out that I'm just dealing with SCSI voodoo versus a truly fried/broken SCSI controller.

I really hope to get it up and running with SCSI to make it usable!

Howie

 

flowers

Active member
------

So what I've concluded:

(1) The Quadra can see that HDs are connected to the internal and external SCSI busses, but it treats the drives as unrecognizable and fails to mount them.

(2) The CD-ROM drive behaves the same way. A known good external Apple CD300 drive acts the same - will either spit out the installer CD or tell me that the disk is unrecognizable and ask me whether I want to initialize it (which is strange to me since it is a CD).

(4) It's NOT a defective SCSI cable.

(5) It doesn't seem to be a termination issue since the HDs work with my IIci and G3 w/o messing with terminator power or jumpers. - But maybe the Quadra is THAT picky?

------

I think that the macintosh works as the SCSI Controller seen the HD; even the External SCSI CD300 works .. but probably is needed to check if :

- Was the HD inside the SCSI Chain or did you connect the SCSI drive 300e as first unit doing the termination ? 

In my opinion you have a not working HD inside the macintosh, discpnnect it and then try the working cd 300e  inserting a termination in the back of it. Then try to see if in this way the macintosh see it starting from the Floppy disk drive that is also working correctly fro what i read...

Is only an idea :)

Michele

 
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CelGen

Well-known member
See if you can find a copy of Snooper. It's old but it's an amazing diagnostics utility that could also boot standalone from a floppy. It had a number of SCSI tests including device detection, controller testing and destructive disk testing (doesn't need a valid apple driver or filesystem to do this and IF it does anything then it means that the controller is fine and it can write and read back data on the bus)

Here's another possible twist that I haven't explored yet but might be worth mentioning: The Quadra came with a National Instruments NB-GPIB-P Nubus IEEE 488 controller card installed. I had removed that and set it aside prior to recapping the mobo and then forgot all about it until just now. Is it possible that because the system was previously configured with this bus card, the SCSI busses now cannot function without it installed? I have to dig it out from storage to reinstall it, but if it is extremely unlikely this is reason then I won't bother.
Those are fancy cards if you have any hardware that supports GPIB. National Instruments still has the drivers and software available on their website but no, weather or not the card is installed would not affect the machine.

 

Hotdog Zanzibar

Well-known member
After having uniserver recap my Q840 board, I'm having the exact same problems as epoxy2600.

No internal or external SCSI drive will mount at startup - and I've already confirmed the drives are good on the Q950. All I get after the RAM test is the blinking ?. The computer also booted successfully before the recap, but was showing clear signs of cap leakage. 

The floppy drive will not boot a Disk Tools disc -- could be a bad floppy drive. I have yet to test one I know is working. 

Sounds like the cap goo was on there too long. :(

I don't have a SCSI card to test from, and the ones on eBay are all $40-$50. Going to post in the Trade Forum to see if anyone has one they'd be willing to sell or trade. 

Has ANYONE had any luck repairing these boards? Talk about feeling defeated... gah.

 

uniserver

Well-known member
i had to look back at our chat, just because it always sounds funny when people say something " worked " before.

The computer also booted successfully before the recap
I used the Q840 for a few days last year and it worked great. Recognized all the drives, RAM, everything. The last time I booted it, I recall the sound was getting pretty weak. So I'm thinking positive!"

So in regards to the timeline, just because something vintage powered up and worked a year ago, absolutely does not mean that its going to work now.

If someone sends me an 840av to re-cap and the only problem, (at that every moment) is just scratchy sound but everything else works, then

a recap will most likely bring everything back.

Now with guys like the op of the thread when he sent it to me,  the thing was completely dead... so the fact that everything now is back up and working... just no scsi, is kind of a good thing.

and in your case even though the scsi use to work a year ago,  doesn't now... but you said the sound is working. so that is a good thing.

if you look at this picture you will see these 2 little stinkers and because of gravity, the the goo spills out and runs stright down rotting up the scsi chip legs.

Screen Shot 2015-10-05 at 10.53.04 PM.png

one thing you could try is maybe going around the pins of SCSI chip one more time with a tooth brush

and some 91 % ipa,  and maybe try to squirt some IPA somehow under the SCSI IC.

the 840av is a serious problem.

so anyone with an 840av in storage , or one that works now and hasn't been re-capped...  

i highly suggest you get on that.

Even if at the least you pull the MB, remove the caps... wash all the goo off... and dry the main board with an air compressor. ( for now )

 

Hotdog Zanzibar

Well-known member
Yep, suffice to say I've learned my lesson... going to thoroughly wash all the boards I have left until I can get them all recapped!

Just to be clear -- I'm absolutely not saying any of this was caused by Charles's recap job -- exactly the opposite! I was going through financial troubles over the past couple years and every time I started saving up for a "recap fund," something would happen and I'd have to use the money for that instead. So the machine basically sat for a year before I could get the board to him.  :-/

I should've just said "screw it" and sent the boards to him one at a time, which is what I'll do from now on, starting with the Macintosh TV board & tuner later this month. :)

 
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