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Liebo

macrumors regular
Original poster
Sep 17, 2013
121
46
So I recently got a B&W Power Macintosh G3 which beeps once with no RAM installed. If I put a known bad stick of RAM I do get three beeps. With known working RAM (no other Mac so tested in a PC) I get no beeps but I also get no chime. I've bought a replacement graphics card hoping that was what was at fault and it's exactly the same.

I didn't get a drive with it so I hooked up an 8.4 GB Seagate I had laying around just in case it needed a hard drive in to boot.

The CPU gets warm as it should but no USB keyboard lights come on either (PC keyboard should work right?)

Any ideas? I suspect the 1998 dated battery is dead but does it need to be working to boot? I'll buy a new battery if so.
 
You probably have the wrong type of RAM. This is from everymac.com:

Formally supports 100 MHz PC100 SDRAM (3.3v, unbuffered, 64-bit-wide, 168-pin). However, PC133 SDRAM is backwards compatible and may be used as well.

RAM that would workin a modern Windows computer would most likely not work in this computer. You'll probably have to buy some online if you want this PowerMac to ever work again.
 
RAM that would workin a modern Windows computer would most likely not work in this computer. You'll probably have to buy some online if you want this PowerMac to ever work again.
I sincerely doubt he used modern RAM. That would not even fit in the RAM slots due to the different shape of RAM. SDRAM has 2 notches, whereas all DDR ram, 1 to 4, has only one. He most likely tested it in a Windows PC of similar vintage.
 
I sincerely doubt he used modern RAM. That would not even fit in the RAM slots due to the different shape of RAM. SDRAM has 2 notches, whereas all DDR ram, 1 to 4, has only one. He most likely tested it in a Windows PC of similar vintage.
True. But based on what he's saying, I'd still guess that he's using the wrong RAM of some type. Could you please give us more details on the RAM you're using, Liebo? If the RAM has a sticker on it, what does it say?
 
It's PC100 64MB. I've also tried 256MB PC133.
 
True. But based on what he's saying, I'd still guess that he's using the wrong RAM of some type. Could you please give us more details on the RAM you're using, Liebo? If the RAM has a sticker on it, what does it say?
PC100 = PC100. PC133 = PC133. The general rule is that there isn't a difference, as long as it is desktop RAM. Unless it's some weird server RAM, but I'd very much doubt his old PC would boot with that either.

Have you tried hitting the PMU and CUDA switches? They are near the battery, if I remember correctly. The computer should boot with a dead battery, but you can pull it out regardless, for testing's sake. Also, try holding CMD + OPT + P + R while booting, let go if you hear chiming. If nothing of this works, you can try using some contact cleaner and a piece of regular printing paper to clean the contacts in the RAM slot. Maybe they are dirty/corroded which prevents it from booting.
 
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I don't have an Apple USB keyboard so what are the equivalent on a PC keyboard please?

I picked up a new battery (£12.99!!!) so will try that later when I get home from work.
 
Thanks but no dice. USB keyboard unresponsive I.e. Caps lock doesn't come on when pressed.

New battery made no difference.

I've pressed the buttons on the main board labelled S4 which appears to reset the Mac. And s5 which turns it on and off.

Anything else I can try?
 
Any progress? If not, try looking up the RAM you need and then buy it. RAM is really cheap these days, at least for older computers. I know you have one that works, but it can't hurt to try. Also, if you don't mind the cost and trouble, I'd recommend replacing the PRAM battery, but if that's too much trouble or too pricey then try some other things first. But first try getting the new RAM and let us know what happens. Oh, and don't forget to remove all internal RAM before putting the new one in.
 
Any progress? If not, try looking up the RAM you need and then buy it. RAM is really cheap these days, at least for older computers. I know you have one that works, but it can't hurt to try. Also, if you don't mind the cost and trouble, I'd recommend replacing the PRAM battery, but if that's too much trouble or too pricey then try some other things first. But first try getting the new RAM and let us know what happens. Oh, and don't forget to remove all internal RAM before putting the new one in.

Let me ask a question-do you own any of these computers you've been trying to troubleshoot? I've seen you make a lot of "shotgun" suggestions to fix problems that really don't really accomplish anything.

Going back to the OP:

1. You say you've replaced the PRAM battery. This certainly won't hurt anything, but B&Ws will boot with a dead battery or no battery installed

2. Bad or incompatible RAM give the same response-a loud noise on start-up which you've seen. You've tried a couple of different sticks-it's highly unlikely that all are bad. I've found these machines to be fairly forgiving in terms of RAM installed.

3. Press and hold the PMU reset for several seconds. I think you've found the button, but just to be sure it's the one closest to where the power cable plugs into the LoBo

4. This is a long shot, but I had a B&W at one point that REALLY didn't like an optical drive I'd installed. As a quick remedy, try unplugging the ribbon cable that goes to the ODD.

I think your logic board board is fine since you do get SOME response from it.
 
Let me ask a question-do you own any of these computers you've been trying to troubleshoot? I've seen you make a lot of "shotgun" suggestions to fix problems that really don't really accomplish anything.

Going back to the OP:

1. You say you've replaced the PRAM battery. This certainly won't hurt anything, but B&Ws will boot with a dead battery or no battery installed

2. Bad or incompatible RAM give the same response-a loud noise on start-up which you've seen. You've tried a couple of different sticks-it's highly unlikely that all are bad. I've found these machines to be fairly forgiving in terms of RAM installed.

3. Press and hold the PMU reset for several seconds. I think you've found the button, but just to be sure it's the one closest to where the power cable plugs into the LoBo

4. This is a long shot, but I had a B&W at one point that REALLY didn't like an optical drive I'd installed. As a quick remedy, try unplugging the ribbon cable that goes to the ODD.

I think your logic board board is fine since you do get SOME response from it.
I own similar Macs and these are just troubleshooting techniques I use. They may not work for the certain model, but nobody else has helped in a while so I tried my best to. And I completely forgot about the PMU reset- certainly do that! Thanks for reminding me.
 
I've tried the RAM And pressing the reset buttons multiple times. Thanks for all your help.
 
Sounds like a failed logic board, CPU, or even a flaky power supply. I have the CPU fail on a blue and white G3 back in 2005, and I will call the problem being similar. If you can find a replacement ZIF CPU module, it might be worth tossing one in just to see if that takes care of it. I would also go through the power supply pins with a multimeter to make sure you were getting all the correct voltages.
 
I'll hold on to this machine whilst I try and find a working one to do those tests but I've spent too much on this machine now already.
 
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