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Possible monitor trouble?

Started by Barrister, July 18, 2011, 10:00:33 AM

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DontSayBanana

Quote from: Barrister on July 19, 2011, 12:01:01 PM
Quote from: Grey Fox on July 19, 2011, 11:42:26 AM
I'd try a different PSU first but it's something I have on hand, you might not.

IIRC correctly you have an insane amount of ram, try reducing it to see if anything happens.

10GB of RAM is hardly insane. :P

No Mac Pro compatible PSU on hand.  Taking out some RAM is pretty trivial so I could give that a try.

I'll take a quick look, but I'm almost certain it is not a blown capacitor.  For whatever reason the monitor is being forced into sleep mode - not that it isn't receiving an image at all.  When I power the monitor up I can see a perfect screen image - for all of one second, before the monitor goes back to sleep.

A blown capacitor doesn't necessarily mean no power to the card at all, but yeah, defective capacitors seem to be a thing of the past- that doesn't include damage from surges, though.  All those capacitors and resistors are there to get it to specific voltage within a really small tolerance range; it could be any electrical damage to the card- capacitors, resistors, voltage regulator... another possibility is a burnt-out fan; a lot of cards will stay in standby if the fan isn't working to prevent heat damage.
Experience bij!

grumbler

Quote from: Barrister on July 19, 2011, 12:01:01 PM

10GB of RAM is hardly insane. :P

No Mac Pro compatible PSU on hand.  Taking out some RAM is pretty trivial so I could give that a try.

I'll take a quick look, but I'm almost certain it is not a blown capacitor.  For whatever reason the monitor is being forced into sleep mode - not that it isn't receiving an image at all.  When I power the monitor up I can see a perfect screen image - for all of one second, before the monitor goes back to sleep.
Could it be overheating?  Have you cleaned out the air intake and exhaust on your vid card cooler?
The future is all around us, waiting, in moments of transition, to be born in moments of revelation. No one knows the shape of that future or where it will take us. We know only that it is always born in pain.   -G'Kar

Bayraktar!

Barrister

Quote from: grumbler on July 19, 2011, 05:09:27 PM
Quote from: Barrister on July 19, 2011, 12:01:01 PM

10GB of RAM is hardly insane. :P

No Mac Pro compatible PSU on hand.  Taking out some RAM is pretty trivial so I could give that a try.

I'll take a quick look, but I'm almost certain it is not a blown capacitor.  For whatever reason the monitor is being forced into sleep mode - not that it isn't receiving an image at all.  When I power the monitor up I can see a perfect screen image - for all of one second, before the monitor goes back to sleep.
Could it be overheating?  Have you cleaned out the air intake and exhaust on your vid card cooler?

I haven't opened the case.  I've had cards fail before and the symptoms were nothing like this, but it certainly couldn't hurt to clean out the computer.
Posts here are my own private opinions.  I do not speak for my employer.

Barrister

Cleaned out the dust.  Removed some RAM - symptoms are identical.

Took out the vid card - couldn't see much due to the large plastic shroud, but nothing obviously out of order.  Same with a visual inspection of the motherboard.

This is about as far as I can take this myself.  Taking it to an Apple authorized shop tomorrow.  Heading out of town on Thursday anyways, so hopefully they can fix it fairly cheaply before I get back.
Posts here are my own private opinions.  I do not speak for my employer.

viper37

Quote from: Barrister on July 19, 2011, 10:58:19 PM
so hopefully they can fix it fairly cheaply before I get back.
"cheaply" and "Apple"?  Well, I suppose you do believe in miracles.
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Barrister

Quote from: viper37 on July 20, 2011, 10:14:46 AM
Quote from: Barrister on July 19, 2011, 10:58:19 PM
so hopefully they can fix it fairly cheaply before I get back.
"cheaply" and "Apple"?  Well, I suppose you do believe in miracles.

The Apple Certified technician couldn't find anything wrong with my machine either.  Cost me $60. <_<

So I tested two different monitors, and both showed the same symptom.  And apparently it's not a problem with the Mac itself.

But I just had a eureka moment.

The only common element when I tested both monitors was the DVI cable.  And in fact when I went to hook up this old POS Dell that was sitting in the closet (which only has a VGA out, not DVI) I initially went to use a DVI -> VGA adaptor using the same cable, and I couldn't get a signal.  But I didn't think anything of it, as I just grabbed a simple VGA cable I had sitting in a big box of miscellaneous computer stuff.

I'm 99% sure I have a bad DVI cable.

As soon as the baby wakes up, we're off to a computer store.   :cool:
Posts here are my own private opinions.  I do not speak for my employer.

Barrister

Well fuck, it isn't the DVI cable.

I'm going to get methodical about this.  Try every possible combination of components to see if I can isolate where the problem is.
Posts here are my own private opinions.  I do not speak for my employer.

Barrister

So I'm still trying to match up why the Mac repair shop couldn't find any problem, but I clearly do.

I wonder if the problem is the DVI out from my graphics card.  The Apple branded 5770 has both a mini-DP and a DVI connections.  I don't have a mini-DP monitor, so I've only used the DVI.  Maybe the repair shop only connected using mini-DP?

:hmm:

Any suggestions would be most appreciated by the way.
Posts here are my own private opinions.  I do not speak for my employer.

derspiess

#23
Quote from: Barrister on August 01, 2011, 12:11:48 PM
So I'm still trying to match up why the Mac repair shop couldn't find any problem, but I clearly do.

I wonder if the problem is the DVI out from my graphics card.  The Apple branded 5770 has both a mini-DP and a DVI connections.  I don't have a mini-DP monitor, so I've only used the DVI.  Maybe the repair shop only connected using mini-DP?

:hmm:

Any suggestions would be most appreciated by the way.

I was going to suggest maybe a messed-up DVI port. 

Btw have you tried swapping in a different video card yet?  Even if you have to buy an el cheapo card to do it, it might be worth doing, assuming you can find one that is Mac-compatible.

edit: or get one of these puppies to hook up your monitor to the mini-display port.
"If you can play a guitar and harmonica at the same time, like Bob Dylan or Neil Young, you're a genius. But make that extra bit of effort and strap some cymbals to your knees, suddenly people want to get the hell away from you."  --Rich Hall

Barrister

Quote from: derspiess on August 01, 2011, 12:49:08 PM
Quote from: Barrister on August 01, 2011, 12:11:48 PM
So I'm still trying to match up why the Mac repair shop couldn't find any problem, but I clearly do.

I wonder if the problem is the DVI out from my graphics card.  The Apple branded 5770 has both a mini-DP and a DVI connections.  I don't have a mini-DP monitor, so I've only used the DVI.  Maybe the repair shop only connected using mini-DP?

:hmm:

Any suggestions would be most appreciated by the way.

I was going to suggest maybe a messed-up DVI port. 

Btw have you tried swapping in a different video card yet?  Even if you have to buy an el cheapo card to do it, it might be worth doing, assuming you can find one that is Mac-compatible.

edit: or get one of these puppies to hook up your monitor to the mini-display port.

When in doubt, go back to square one.

I retested both monitors, and both computers (the Mac Pro and an old POS Dell).  My initial suspicion had been a bad monitor, but I know I couldn't get a signal from the Mac to the older monitor.  But when I went back today, now I can get the old monitor to work, and can't get the new monitor to work on either computer.

So as it's only a year old, I get to fight with Samsung over warranty.  Of course I seriously doubt I kept my old receipt - but it's supposedly a 3 year warranty...
Posts here are my own private opinions.  I do not speak for my employer.