Member Avatar for mjanep

Hi, I'm new here. I have this problem in the office. We have a dual processor G4, which does not start. All you get is a no entry sign on the monitor once you start it. We tried to troubleshoot it by swapping parts like the ram, hard disk, removing the external cd drive but this did not solve the problem. We also tried to boot it from the boot disk but it doesn't work. Previously, we had changed it processor and lessen it's RAM 256 since the other 256 got busted. Please can you help me. I'm desperate. Thank you so much

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A compact, prioritized checklist to complement the replies from and for . The goal is to separate a firmware/OS mismatch from basic hardware failure and to suggest the next practical steps before a board-level repair.

  • Identify exact model and firmware/OS compatibility. Model names (QuickSilver, MDD, Mirror Drive Doors, etc.) determine which restore discs and firmware updates are valid. Model/serial info on the case or the original restore media will help narrow supported OS builds.
  • Check POST behavior. A successful startup chime usually means the logic board runs POST; absence of a chime points toward PRAM/PMU/PSU or board issues. Perform an NVRAM/PRAM reset by holding Command-Option-P-R at power-on until the second chime.
  • Confirm boot-media compatibility. Boot from a known-good retail PowerPC install DVD (hold C at startup) rather than a model-specific restore disc from a different Mac. If the optical boot is ignored, try a different known-good disc or drive.
  • Use FireWire Target Disk Mode as a diagnostic and recovery route. Hold T at startup and connect to another Mac; if the internal drive mounts, data can be copied and a fresh install attempted from the working Mac.
  • Firmware and CPU concerns. If a non-stock CPU was installed, verify that the processor is supported by the Mac’s firmware. Some firmware updates are required for upgraded CPUs; an unsupported CPU can prevent a boot.
  • Basic hardware checks before replacing the board: reseat modules (one stick at a time in the correct slot), check CPU seating and heatsink, disconnect nonessential peripherals, and perform a PMU/SMC reset (model-specific—usually involves removing power and following the service note for that G4).

If none of the above isolates the fault, logic-board or power-supply failure becomes likely and board-level diagnostics are recommended. Exact model identifier and whether a startup chime is present are the most useful details for narrowing the cause.

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Member Avatar for Danarchy

Hi, I'm new here. I have this problem in the office. We have a dual processor G4, which does not start. All you get is a no entry sign on the monitor once you start it. We tried to troubleshoot it by swapping parts like the ram, hard disk, removing the external cd drive but this did not solve the problem. We also tried to boot it from the boot disk but it doesn't work. Previously, we had changed it processor and lessen it's RAM 256 since the other 256 got busted. Please can you help me. I'm desperate. Thank you so much

Hello.
Just saw your question. Hope you've gotten it repaired since you wrote this.
I don't know much on tower Macs, but it sounds like you have a monitor problem. assuming that you've tested that the monitor works properly, it sounds like you need a repair person to look at the machine itself. But I don't think the issue would come from bad RAM or an external drive of any kind. That just comes from my limited knowledge. Maybe somebody here knows better.

Good luck,
Dan

Member Avatar for yellow

Need more info..


What version of OS X is it running?
Is it telling you to reboot in multiple languages?
Does it POST (Power On Self Test, aka, chime)?
Have you reseated the replaced processor?
Have you put the old processor back in?
Which model of G4 is it?

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