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PRAM won't zap?

Iamanamma

Well-known member
Has anyone ever had this problem?  I just dragged an old G3 out to try to get it running off of a SSD, and I am getting no video from the built-in video or the ATI video card.  Trag suggested I zap the PRAM (which i should have thought of myself).  When I restart with all the correct keys held down, it starts up, but I only get one chime.  I tried replacing the PRAM battery and switching out keyboards.  No luck.  Still no additional chimes.  Is this G3 dead?

 

Brett B.

Well-known member
How much RAM does it have?  If it's close to the max of 768MB (I'm assuming this is a beige G3, NOT a blue & white) it may take a while for it to complete the memory check at startup... or it may not come on at all.  Mine are both quirky as hell.  Try powering it on normally, then after you hear the chime, hit command + control + power to force it to restart.  I get video 100% of the time if mine do this.

 

Iamanamma

Well-known member
How much RAM does it have?  If it's close to the max of 768MB (I'm assuming this is a beige G3, NOT a blue & white) it may take a while for it to complete the memory check at startup... or it may not come on at all.  Mine are both quirky as hell.  Try powering it on normally, then after you hear the chime, hit command + control + power to force it to restart.  I get video 100% of the time if mine do this.
You assumed correctly, it's a beige mini-tower.  I can't remember how much RAM is installed, and since I can't get the video to work, I can't tell you how much is installed.   The video decided to work for a couple of hours yesterday, but stopped again after I tried to replace the hard drive with an SSD.  I put all of the original components back in, and I still have problems with it.  Quirky as hell is a good description.  I'm gonna try your trick a couple of times.

 

jessenator

Well-known member
Maybe I'm not reading your procedure correctly, so forgive me if I'm way off base here :)   I've only successfully zapped pRAM by holding down alt+cmd+p+r after the initial start chime: e.g. boot, right after the chime, hold the keys, wait for a second chime—if that's what you're already doing, ignore me :)  

Another elementary question here:

Have you had issues with any of the keys? testing it with Key Caps program in Mac OS? Just a thought.

 

Iamanamma

Well-known member
Maybe I'm not reading your procedure correctly, so forgive me if I'm way off base here :)   I've only successfully zapped pRAM by holding down alt+cmd+p+r after the initial start chime: e.g. boot, right after the chime, hold the keys, wait for a second chime—if that's what you're already doing, ignore me :)  
Yes, that's what I am doing.  I don't mind being asked, it makes me take another look and make sure I am doing it correctly.

Another elementary question here:

Have you had issues with any of the keys? testing it with Key Caps program in Mac OS? Just a thought.
Don't I need to be able to see something on the monitor to do that?

 

EvilCapitalist

Well-known member
Are you using a stock Apple keyboard or an aftermarket one?

Even though it shouldn't be the case I've had problems with the one aftermarket keyboard I have and commands like that.  Whether it was zapping the PRAM or booting off a different disk for some strange reason that particular keyboard didn't always work reliably when it came to keyboard commands at boot.  The second I'd switch to a stock Apple keyboard everything went off without a hitch.

 

Iamanamma

Well-known member
Ah, I guess if your VGA monitor isn't working that would be tough—sorry if I'm crossing your posts' wires in my head. Did the Rage128 stop working then?
Sorry, I am crossing posts wires.  The reason I was trying to zap the PRAM was because it was suggested to kickstart my video.  Then the PRAM weirdness started.  I have no video.  Period.  Not from the Rage, not from the native.  

 

jessenator

Well-known member
Taking the battery out will definitely zap the PRAM—sorry I know that was suggested already.

That sounds like there's something deeper going on :/  sorry that's a bit above my pay grade.

The battery is good? PSU still in decent shape? Sorry that's the basic stuff I know on these models.

 
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trag

Well-known member
You should be able to zap the PRAM by holding down the key combination either before or after the start up chime.  I've read, but am unceratin, that zapping it before the chime actually resets more parameters.   Pulling the battery and pressing the CUDA switch should reset everything that is stored in NVRAM/PRAM memory.

For that matter, you could just try pressing the CUDA switch, IIRC, near the back corner of the board near the third PCI slot.

In cases like this, I recommend you remove the PCI video card, leave in the personality card, you need that, but remove the modem card from it, remove all the RAM but one stick, unplug all the hard drive cables, SCSI and IDE.   Don't plug in a keyboard or mouse.    Remove the battery.  With machine unplugged,  hold down the CUDA button for 30 seconds.  Leave the battery out. The Beige doesn't need it to boot.

Connect a known working monitor which is capable of 640 X 480 @ 67Hz to the built-in video.   Power up with the power button on the front (back?  can't remember).  If you get a good start up bong, wait a couple of minutes to see if the monitor becomes active.     If not, try a different memory module.   

If you can't get a good start up bong or video on the monitor, the problem must be on the motherboard or the monitor.  It's unlikely, though possible, all three memory modules are bad.  

If you do get a good start-up screen (gray screen with disk icon and flashing ? mark) start adding components back.  Start with a mouse.  Then keyboard and mouse, etc.

All that said, here's another possibility...   The bus speed and CPU multiplier and cache ratio are controlled by a set of jumpers on the motherboard.  Are those still in their original position?  Does the machine still have the original CPU module installed?  Also, you may wish to check the heat sink grease between the CPU and heat sink.   If it's turned to powder, you could have a simple case of the CPU overheating soon after power on.

 
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Brett B.

Well-known member
These things seem to need to pass the memory test before a PRAM reset is allowed... Hence why it's not working on the first power cycle before you get video.  That's my suspicion anyway. I'd also try removing and reseating EVERYTHING connected to the logic board except the CPU. Clean the edge connectors on any expansion cards you have installed too. 

 

Iamanamma

Well-known member
I pulled out a second G3, desktop style this time and it also refuses to work.  It has a nasty problem on the VRM.  Correct me if I am mistaken, but the capacitors appear to be leaking out the bottom?  There is no bulging on the top.

VRM.JPG

 

Iamanamma

Well-known member
In cases like this, I recommend you remove the PCI video card, leave in the personality card, you need that, but remove the modem card from it,
Couldn't get at one of the screws holding the modem card in place, so I had to leave it there.  It didn't seem to hurt anything, because this:

remove all the RAM but one stick, unplug all the hard drive cables, SCSI and IDE.   Don't plug in a keyboard or mouse.    Remove the battery.  With machine unplugged,  hold down the CUDA button for 30 seconds.  Leave the battery out. The Beige doesn't need it to boot.

Connect a known working monitor which is capable of 640 X 480 @ 67Hz to the built-in video.   Power up with the power button on the front (back?  can't remember).  If you get a good start up bong, wait a couple of minutes to see if the monitor becomes active.
worked.  BTW, the power button is on the front.  I am going to continue to follow your instructions and see if I can find out what is causing this machine to keep losing its mind on me.

 

Iamanamma

Well-known member
It looks like there is something wrong with the IDE Ports or cables.  After I plugged the cable into the one that leads to the CD-ROM, the video stopped working again.  I un-plugged it, and the video works again, although it comes up significantly slower.  I have not yet put the Rage video card back in, all that was left was the USB card and the video card, but with the video failing after I re-attached the CD-ROM, I think the  source of the problem is pretty obvious.  I may just switch everything over to the SCSI bus, and use a SCSI2SD board with the largest SD card I can get authorized.  Thank you for everything! 

 

trag

Well-known member
Do you know what revision of the ROM that Beige G3 has?

The Rev. A ROM did not support Master and Slave devices.   I don't know if having both on the cable would cause such an issue.

I can't remember the numbers actively, but would probably recognize which revision they go with.   You can figure the ROM revision by reading the Apple part number off of the two ROM chips  on the ROM module (unless you have one of the rare EEPROM built ones) or by booting up and then using Apple System Profiler to report the ROM revision.   The latter will be something like $77D.45F1.  The former will be 343S0401 or something like that.

At a guess, it's more likely there's a problem with the CDROM than that there is a problem with the IDE ports.   Could also be a bad IDE cable.   Oh, check for bent pins on on the connectors.    Sometimes one or more of those gets bent over, instead of going into the appropriate hole, and it gets shorted with a cable is plugged in and pressing against it.

Yes, that looks like the caps may be leaking on that VRM.  

 

Iamanamma

Well-known member
Do you know what revision of the ROM that Beige G3 has?
I didn't know, but since you told me what to do to find out, now I do.  The ROM part number is $77D.45F2.  So it's rev B?  I noticed the CD-ROM is set to master.  It is plugged into its own port on the MB, and is the only device on that cable.  I cannot tell what the HD is set to without researching the drive, it isn't marked on the HD like it is the CD-ROM, but again, it is plugged into a different port, and is the only device on the cable.  I had another SCSI2SD and I slid it into the spare 3.5" bay in the tower, and it let me initialize the virtual hard drives on it.  I may go with it as the new solid state option for that machine, seeing as SCSI does not have size limitations like IDE. I just need to find a honking big capacity SD card. 

 
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