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Quadra 700 issue

Quadra 700 issue Hardware 63 posts Oct 28, 2015 — Dec 12, 2015
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?

IMG_3321.jpg.2d170b040cc0db304a7ebfb2d70771a9.jpg


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.

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 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...

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.

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.

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.
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.

Just because it works with a Power Mac doesn't mean it'll work with your Quadra.
:O  It 'really possible?

........If I try a lcd with db15>vga converter?

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?

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...

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?
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

IMG_3323.jpg.02d9b8e5be9b598be3533a672976b4e9.jpg


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.

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.
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?

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

IMG_3328-2.jpg.726ab590a12232c4f7b3fd042fb712db.jpg


Looks to have a lot of goop on there, too.  Could use a clean in general.

Looks to have a lot of goop on there, too.  Could use a clean in general.
I have used a "not dry" cleaner... later i have used a "dry cleaner"

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.

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? 

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? 
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.

mp.ls