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Cube Graphics Issue

A

aalls159

macrumors newbie
Original poster
Jun 13, 2015
28
31
Iowa
Hi, Long Time forum lurker here.
I am wondering if anyone could help me with a issue i am having. Today I replaced a Geforce 2 mx in my powemac g4 Cube with a Geforce 6200. I did this upgrade because I noticed that the Geforce 2 mx graphics card that was with it when i bought the cube was the none cube edition card and was over heating. The Issue is that after doing this upgrade i am getting no video and the power button is blinking on top. I switched to Geforce 6200 back to the Geforce 2 mx and am still having the issue. Was wondering if anyone knew what I need to fix. Thank you.
 
It blinks once pause for a few seconds blinks again and pauses and then appears to powercycle.

**Just looked at it again. It turns on when plugged in flashes once stays on then power cycles and does it all over again**
 
The DC to DC board appears to be secured is not out of its socket but it is a little wobbly.
 
Do you have speakers on the computer? If you don't have the "proper" Cube speakers, any generic USB speakers will work. In any case, hearing a tone through could be diagnostic also.

In the interim, I'd suggest that the symptoms sound like a RAM problem. I'd check the RAM sticks to make sure they are all seated correctly. In addition, it's extremely uncommon but I have killed a stick with static while working on a Cube(only time I've personally done that in 20 years of playing with computers). It's worth pulling the RAM out one at a time and trying to boot wiht one missing.
 
I pulled all the ram and put it back in one at a time will booting in between putting more ram in and reseted the DC to DC board, when i press the power button it now glows for a second then stops glowing but is still on because the case fan is still going. When i press it again it glows then turns off.

** The only usb speaker I have are non functional Cube Speakers that I have yet to find out will they don't work and the foam around the center of the Speaker Is disintegrating. **

**Tested it again a second ago I get the same effect with both The Geforce 2 mx and the Geforce 6200. I have a Rage 128 pro for the cube but have not tried that to see if it works**
 
Last edited:
I removed the battery and pressed the cuda switch and put the battery back in after checking it and the problem still persists. To recap the problem I press the power button and the cube powers on but power buttons light turns off and stays off. With both video cards it displays on video and when I press the power button again to turn it off the and light on the power button glows again and then turns off with the cube. I know it is on during this process because I can here the aftermarket fan in the bottom of the case going while it is on. I ordered a replacement DC to DC board that should be in by friday to see if it is the DC to DC board but it appears fine with no apparent physical damage.
 
I got the Griffin iMic in today to see if that would make it so that I could hook up regular speakers to see if there was a error code beeping from the cube. Hooked it up to both usb ports on the cube and there was no beep code to indicate that there was an issue. Will see if it is the DC to DC board after a used one comes in from ebay on friday.
 
Ok sorry for the long delay was out of town for a bit and then got side tracked. I did the DC to DC board replacement today and the Issue still persist. Now when I was doing the DC to DC Board swap I noticed that the Fan was hooked up to the DC to DC board Directly. So I was wondering if it was possible that I shortened the Riser Board on the Cube? Seeing as the DC to DC board appears to not be the Problem.
 
So the cube is booting up with no video output? Does the drive access light flicker like a normal boot? Can you VNC or ssh into it from another computer?

The 6200 should have pins taped over to work in the cube. Was this the case?
 
@flyrod Don't know where the Drive access light is on a cube, but the power button only lights up when pressed to turn it on or off. The Cube Does not even have a Ip address from my PFsense router. The 6200 does have the Pins 3 and 11 cut when it arrived. I have a Rage 128 and a geforce 2 mx and they don't have video out ether.

@Calum2 what Do you mean by Reflow the board?
 
Quick update. I got a new video riser board to determine it that is the problem and the issue persisted. I also aquired a Firewire 400 cable and connected it to my powermac g5 quad and the cube and turned the cube on and pressed the t key and the Cube did not show up on the g5. To see if I had any power to the ports I hocked up a usb fan to the cube and that did work. The cube is also lighting up the 4 light on the motherboard when powered but not booting. Wondering if I blew the CPU or the mother board?
 
It sounds like the computer is not booting. And the behavior changed when you re-seated the ram? Did you reset the PMU? Here is how to do that:

Many system problems can be resolved by resetting the PMU chip. When you have a
computer that fails to power up, follow this procedure before replacing any modules:
1. Disconnect the power adapter from the computer and check the battery in the battery
holder. The battery should read 3.3 to 3.7 volts. If the battery does not have the
minimum voltage, replace it, wait ten seconds, and then reset the PMU (refer to the
next step). If the battery is good, go to the next step.
2. Press the PMU reset switch (S1) once on the logic board. Make sure the connector J4
on the video riser card and the video riser card is installed in its connector, then
proceed to step 3.
Warning:
Do not press the PMU reset switch a second time because it could affect
the PMU chip. S1 is located on the logic board, under the video card, near the edge
of the logic board at the end opposite the video ports.
3. Wait ten seconds before connecting the power (adapter) and turning on the computer.
If the computer turns on, go to the next step. If the computer does not turn on, there is
something else wrong with the computer.
4. Use Apple Hardware Test to check the computer.
 
Thanks for your reply. Here is what I have done on your list.
1 The behavior changed the 1st time I rested the ram and have not changed since then. ***before it flased the light under the touch power button, now it only lights up when pressed.*****
2 I have replaced the battery in the battery holder and have had no success.
3 Have pressed the PMU reset (right under the video card) and no success
3.5 By Connector J4 do you mean the black cord hooked up by 3 Prongs above the brown connector? then yes it has be receded several times.
4 No I have not done the Apple Hardware Test because I can't see the screen also How do you do that on power macs? I know it is different from Intel macs.
5 Other info: the Cube will not go into target disk mode (have tried several times with it hooked up to my powermac g5 quad and 20in g4 imac), The g4 speakers don't make any sounds when connected (tested recently with speakers from my second cube), the usb ports are DO have power as I tested then with a usb power external case fan, lastly like stated above the cube powers up when pressed with the power button the light turn off does not boot but is powered because the added case fan is still powered until you press the power button again to turn it off.

Thank you for your replies and help flyrod
aalls159
 
That is sounding like a bigger problem. If the fan and hard drive spin up, then it has 12v, and if the USB ports have power then it has 5v. If you have a volt meter you can check for 3.3v. If it has all that then the VRM should not be the problem. Did you remove the CPU card at any point, or just the video card? The next thing I'd check is the power button. If you remove the top plate with the button, and the wire connected to the logic board, then briefly short pins 4-5, then a cube will normally boot up fine without a power button attached. If it won't do this, then I'd suspect a bad logic board or CPU card.
 
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No I never removed the CPU card at any Point only put the geforce 6200 in, which i suspect had the wrong pins cut after reading over it and some googling. I bought the geforce 6200 preflashed on ebay and it already had the cube bios installed and the pins cut. Flyrod which pins are pins 4-5 on the on the cube for the power buttons to test with the short test?
 
The video card uses the 3.3v part of the VRM. If that got smoked it could explain what you're seeing. Do you see any roasted looking parts on the VRM, or can you check the 3.3v with a meter?

In this picture on the bottom left corner of the logic board is the back side of the connector for the power button. To boot the cube without the button briefly short the two right most pins. I marked it with a black pen.

cube_Test.jpg
 
There was no roasted looking parts on the VRM(DC to DC board) and the Original VRM and Video Riser board are not currently in the cube they were swapped with new ones for diagnostic purposes. Is the part you marked the top and bottom right pins beside the black cord on the left side of the Picture?
 
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