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schalliol · Nov 13, 2007, 09:34 PM

Thanks for clicking.

I have a G4/733 Digital Audio Mac with a GeForce 4Ti (4600) for Mac AGP graphics card. It was a very nice (and expensive) card at the time. Today I discovered that I had no video when starting up. I do hear the startup sound, hard drives spin up, mother board lights, and the fan on the GPU starts, but it doesn't sound like the machine is attempting to start. I tried to zap the PRAM, but I couldn't get additional startup sounds I'm used to, while holding down the buttons. I'm actually planning on getting a new CPU (dual 1.8GHz G4 from Sonnet has been ordered) and the machine has a sonnet SATA card with 750 hard drive and an IDE RAID, so I don't want to scrap the machine. It doesn't sound like the graphics card to me, since that shouldn't cause the machine not to attempt to boot (I don't think), so I'm guessing it's the CPU or the logic board. Does that make sense? Do you have any good guesses for me? Thanks so much!

reader50 · Nov 13, 2007, 11:09 PM

Try changing the battery. Radio Shack #23-026 will do.

Lateralus · Nov 13, 2007, 11:28 PM

Yeah... No.

If you're unable to get video, your problem is beyond the realm of control of a PRAM battery. Don't waste the money or the trip.

Do you have a secondary PCI or AGP video card you could install to at least see if the system is giving a video signal?

schalliol · Nov 14, 2007, 12:03 AM

Originally Posted by Lateralus

Yeah... No.

If you're unable to get video, your problem is beyond the realm of control of a PRAM battery. Don't waste the money or the trip.

Do you have a secondary PCI or AGP video card you could install to at least see if the system is giving a video signal?

Yeah, I'm pretty sure that even if the battery is dead that I'd get video. I'll see if I have an AGP card around that works in Macs. I think I have a first gen AGP G4. Strangely, it seems cheaper to get a logic board than a replacement AGP card...that works in Macs.

reader50 · Nov 14, 2007, 12:09 AM

Some Macs with dead batteries can fail to boot up, with a black screen. Check the battery with a voltmeter, anything under 3 volts is replacement territory. It should be fairly close to the 3.6 volts listed.

Your G4 has passed the 5yr age, where the factory batteries start to run out.

schalliol · Nov 14, 2007, 12:11 AM

In that case, that seems to be a design flaw. I'll make sure to pick one up. It wouldn't hurt to have a new batt anyway.

Lateralus · Nov 14, 2007, 12:45 AM

reader, I hate to argue with you on this, but; The PRAM battery is not the cause of an issue like this.

Once upon a time, the PRAM battery could affect critical boot functions in a Mac. But that was during the Performa era. It's outdated knowledge that has absolutely zero bearing on any New World ROM machines.

Suggesting something like using a voltmeter to check the PRAM battery only serves to greatly over complicate things.

schalliol · Nov 14, 2007, 01:03 PM

Lateralus, that was my understanding also. Since the battery was cheap, I popped one in anyway. I was able to find a puny AGP video card and put that in. The card did allow the machine to boot, and is currently running again. It's a real bummer, as I liked the card that was in it and logic boards are far cheaper! Thank you all for the help!

Lateralus · Nov 14, 2007, 01:30 PM

Well, glad you're up and running. At least we know it isn't something more critical like a fried logic board (which could have taken other components down with it).

Video cards rarely just 'die', especially when running at or below factory clocks (Apple prefers below). Just out of curiosity, did you hear any pops when you turned the machine on and discovered you had no video?

Look at the graphics card and looking for any residue or char marks around the capacitors.

schalliol · Nov 14, 2007, 01:40 PM

Thanks for the thoughts. Yes, I'm glad nothing went with it. The card looks a-ok to me and I didn't hear anything abnormal.

reader50 · Nov 14, 2007, 03:14 PM

Did you try the old card with the new battery? Lateralus is generally right, the (dead-battery black-screen) issue was *supposed* to go away with the old-world-ROM machines. But about once a year, we see a problem posted that traces a modern Mac to that very issue. I suggested the battery because it's easy to change and way cheaper than a motherboard or video card.

I did try to search up prior examples, but Search is really sucking lately. Tried to search for posts by me with "battery" in them - it didn't even find my post above. Nada results found. We need to look into that.

Eug · Nov 14, 2007, 05:08 PM

Did you try simply reseating the video card?

If you decide on getting a new nVidia card, just be aware of the Leopard G4 nVidia 6x00 bootup delay issue.