Thread
Quadra 700 issue
Sorry fo my poor english...
I have buy used Quadra 700, first times I powered up it not immediately switch on but... after some minutes! And with power button I not able to power off, if i push the switch the mac only reset... And now after some test and cleaning of the pcb it never switch on. I able to switch on only with a bridge pin 9 and 10 of psu or if I plug the psu in the motherboard with power cable plugged.
But I have another problem... this is a screenshot of my screen (without hdd), recap solve all my problems? What caps i need to change?
I have buy used Quadra 700, first times I powered up it not immediately switch on but... after some minutes! And with power button I not able to power off, if i push the switch the mac only reset... And now after some test and cleaning of the pcb it never switch on. I able to switch on only with a bridge pin 9 and 10 of psu or if I plug the psu in the motherboard with power cable plugged.
But I have another problem... this is a screenshot of my screen (without hdd), recap solve all my problems? What caps i need to change?
A recap is pretty much need for the Quadra 700. Surprisingly, there isn't a Quadra 700 tutorial on the Wiki.
I'm sure Uniserver knows which caps need replacing.
I'm sure Uniserver knows which caps need replacing.
Uniserver help me! 
Quadra 700 have only 3 types of caps, and all small and yellow
I order a set of tantalum 16v 10uF and 16V 22uF? ... other capacitor is too small to read capacity.
Quadra 700 have only 3 types of caps, and all small and yellow
I order a set of tantalum 16v 10uF and 16V 22uF? ... other capacitor is too small to read capacity.
Quadra 700 has all solid state caps on the LB and should not need recap. in the case of this guy I would tell you to make sure your pram battery has not exploded and if that's ok look into recapping the power supply...
Sure? I know tantalum capacitors not have a unlimited life... Battery is new and the old not have lose acid, the psu seems to work good, voltages are stable and in tolerance
Check the VRAM.
Could be, but: how can I do? The problem is the same with and without vram simm's, if exists a issue is on the vram onboard
Do you have vram modules installed? Take them out if you do since the logic board has vram onboard...
To my knowledge no Q700 has needed a recap, so you can understand why we doubt that's the case.
Try a different monitor and cable.
Try a different monitor and cable.
I use a Apple Multiple Scan 720, with powermac work perfect
@360alaska
I already tried with and without vram simm, no difference.
Just because it works with a Power Mac doesn't mean it'll work with your Quadra.
there could be a dead tantalum.
can you take some good quality pictures of your main board and maybe we can have a look and maybe spot something wrong?
can you take some good quality pictures of your main board and maybe we can have a look and maybe spot something wrong?
I have run a Q700 with an LCD monitor and an adapter, so it's definitely possible to do. Whether you have a good adapter or not would be the question...
Yes, is probably. I have tried with the tester (in continuity):
The two caps near psu socket and the caps load energy from tester.
The small five caps near power swich, three is good, one measure "0", and another one measure a fixed value (all other have a variable value... load energy).
Two caps is damaged?
This is a picture of the motherboard before cleaning
Try the VRAM in pairs. Just a guess, but I think they can go in two at a time since there are six slots. So just try two, then remove those and try another two.
edit: Yes, they can go in pairs. I just checked mine. In mine, the pair is in the two slots to the left as you look at the picture you posted. So the slots furthest back.
edit: Yes, they can go in pairs. I just checked mine. In mine, the pair is in the two slots to the left as you look at the picture you posted. So the slots furthest back.
Thanks, but I have a vram on-board (512kb) and without vram simm's the problem is the same.
I could be wrong but is your PRAM battery in backwards?
i am wondering if the onboard vram has gone bad... I think your best bet is try to hit ebay and follow what an other had mentioned, Try a Nubus Video card. you should be able to pick one up for decent low price. The picture you posted is ok, but the quality is not good enough where i can tell if there are legs of I/C's that are bent over or touching. I wonder if mike Techknight wants to throw in his feedback?
This picture have best quality: http://discoremoto.cheapnet.it/apmarmotta/IMG_3327.jpg
The board is cleaned
This three caps are bad (with my tester)... is very close to RAMDAC and PowerSwitch
Looks to have a lot of goop on there, too. Could use a clean in general.
Just use warm water and a gentle brush. I find paint brushes work really well. Shake water off and use compressed air or hairdryer to move water out from under chips. Then dry in an oven at 120 degrees F. Too hot is bad. Occasionally pull form oven and shake to get water out.
This is a great inexpensive method that I have used many, many times.
This is a great inexpensive method that I have used many, many times.
You need a VRAM testing program, I wonder if one of the common diagnostic softwares out there could test it. Because the issue could be int he VRAM, but it could also be in the RAMDAC.
Also those 3 caps being bad, highly unlikely, what meter?
Also those 3 caps being bad, highly unlikely, what meter?
With tester in continuity (ohm) good capacitor load and release energy, tester show a variable numbers. With this three bad capacitors my tester show only a fixed value of "0" or "0,15".
And my problems with powerswich is a confirmation (is not certainly vram related)
I thought caps can only be tested with an ESR meter unless removed.
Depends on the circuit those caps are in.
Yes tantalum capacitors short, BUT.. you need to remove them to double verify.
Yes tantalum capacitors short, BUT.. you need to remove them to double verify.
You are right... I have removed the caps from the PCB and now is not in short. In any case I order a new caps.
This caps is 47uf 6 volts? It should be replaced?
The fact that moving the mouse left that artifacting is a clear indication it's a digital issue.
Tantalums have two failure modes. Dead short or blown up. They don't gracefully drift out of spec and when they die they make it pretty obvious as you have discovered.
Keep all your VRAM pulled as you mentioned that it's happening with it removed. This narrows the fault down to bad onboard VRAM or a problem with the video chipset. If you can, find a copy of Snooper and run the VRAM test.
no you are wrong, i'v removed plenty of overheated tantalum caps that were no good BUDD.
some weren't even that much discolored... and a black tantalum cap you would never know.
i personally don't like them.
some weren't even that much discolored... and a black tantalum cap you would never know.
i personally don't like them.
I wanna try to change black caps (see picture above), I have some yellow caps with 47uf 16v, they are fine? (the original is 47uf 6,3v)
As long as capacitance is the same, voltage rating shouldn't matter too much?
c
c
Buddy, that's a shorted tant. Read my post again to see that was one of the failure modes.
Is correct to use caps with more voltage? (6,3v>16v)
I already I have them... and new 6,3v 47uf case "D" is hard to find
I already I have them... and new 6,3v 47uf case "D" is hard to find
iv had them be massively out of SPEC and not shorted BUDDY>
Using cap with a higher voltage will not be a problem as long as the capacitance is the same
If you can't make it work, you can always find a Quadra 800 board, That's what I did(although there was'nt anything wrong with my Q700) and my Q700 board is in my IIvx Why are we so determined that it's the caps and not the VRAM? It's a heck of a lot easier to pop in a NuBus video card than it is to replace caps.
The problem is not only the video output, power switch random not work and is impossible to power off (I disconnect the power cord). Change caps is a easy operation end low cost, if not work I change the logic board or buy nubus card
I'm getting ready to throw a Q650 mb in a q700 case, and see what happens. project for later in the week.
The only issue you'll run into is that you'll have to repin the speaker. Everything else is in the same place, although, I wish I knew how to change the gestalt via hardware back to Q700 so that way nobody can really tell unless you open er up.
Awesome man!!... yeah and its cool the 650 can accept 512 megs of ram .. that is ridiculous.
I wanted to do it (650 logic board), but then I thought that I want to original.
I have replaced the caps but the problem remain the same... Now I have a nubus card and with this the video output is perfect! I need to replace the onboard vram?
Other problem is the power switch, why my mac not poweroff when i push the back button? It only restart... I only test it without disks, mac need system installed for correct power management? Keyboard on/off not work, and power on take log time (long press of power switch).
Other problem is the power switch, why my mac not poweroff when i push the back button? It only restart... I only test it without disks, mac need system installed for correct power management? Keyboard on/off not work, and power on take log time (long press of power switch).
Yeah, a system would likely help. The switch isn't twisted into "auto reboot" position, is it?
Another problem 
Quadra start with System 7.1 disk utility, but no hdd... try to initialize and hang at verifying. I try to format same drive with powermac and all good, move the drive to quadra and not mount in desktop, I launch Apple Hd sc setup press test and pop-up "problems writing data to drive". Internal or external, same issue. Why?????????
Is the original 120mb apple hdd.
I use generic system 7.1, quadra have a special disks?
Quadra start with System 7.1 disk utility, but no hdd... try to initialize and hang at verifying. I try to format same drive with powermac and all good, move the drive to quadra and not mount in desktop, I launch Apple Hd sc setup press test and pop-up "problems writing data to drive". Internal or external, same issue. Why?????????
Is the original 120mb apple hdd.
I use generic system 7.1, quadra have a special disks?
I have buy a new motherboard! Power switch problem solved, scsi problem solved... video problem remains the same! However very similar!
I have buy a motherboard with the same defect of my old one? No problem, I have a nubus card and work pefect, but.........
I have buy a motherboard with the same defect of my old one? No problem, I have a nubus card and work pefect, but.........
yeah just keep the nubus video card in there… or change the vram with a hot air reflow station.
or i wonder if you remove it, it will still work from the VRAM slots.?? never tried… might work.
I'd like to know, I not have hot air station, but I'm sure that is the solution ... I find it!
maybe something like this... they are rather cheap these days. http://www.ebay.com/itm/852D-2-in-1-Soldering-Re-Work-Station-Solder-Iron-SMD-Hot-Air-Gun-5-Nozzles-NEW-/272042976768?hash=item3f57066600:g:9ZYAAOSwwbdWQe6O
I have old motherboard for experiments... if I remove 5v pin from vram chip, I not disable it? If this method work, is easy to find damaged chips!
no, just remove the vram as they are bad.
you can try to run it w/o the vram, it will either work or not.
if it works cool..
if it doesn't work then replace the vram from a bad board or a VRAM simm.
you can try to run it w/o the vram, it will either work or not.
if it works cool..
if it doesn't work then replace the vram from a bad board or a VRAM simm.
But I not have hot air... If I use a standard solder?
Alternatively I have a hot air paint remover (but is big...)
I surrender... sure the problem is vram!
I removed all four chips from the motherboard (and simms) easily with my hot air gun (painter remover modified
) but without vram onboard the screen remain black!
I tried for one entire day to solder other ram chip... with no luck! Defect change, but not go away! Possible cause is: my other vram chip is already damaged, when i desolder with my hot gun I have damaged the chips, or (probable) I not able to solder it on the motherboard! Is very difficult, with standard solder, with hot gun... every time seems welded, and instead are not good welded! Various attempts have been in vain...
First I need to be sure my vram chips is good or not, or I loose time.
I removed all four chips from the motherboard (and simms) easily with my hot air gun (painter remover modified
) but without vram onboard the screen remain black!I tried for one entire day to solder other ram chip... with no luck! Defect change, but not go away! Possible cause is: my other vram chip is already damaged, when i desolder with my hot gun I have damaged the chips, or (probable) I not able to solder it on the motherboard! Is very difficult, with standard solder, with hot gun... every time seems welded, and instead are not good welded! Various attempts have been in vain...
First I need to be sure my vram chips is good or not, or I loose time.
Problem solved!
I went from a professional and I welded chips as it should! Now I not have more vram simm's... never mind!
I went from a professional and I welded chips as it should! Now I not have more vram simm's... never mind!