PowerMac G5 Dual 2.0 Chimes but no video

[hackerwayne]

Hi all

Just received a old PowerPC G5 2.0GHz Dual Processor. When i tried to power it on, the Power LED came on as usual and the G5 chimes, but it didnt display any video on the screen. None of the diagnostic lights display red, heres what i've done

- Reseated all the RAMs
- Pressed the PMU button
- Tried CMD+Option+P+R but didn't hear a second chime
- Swapped a good working graphics card
- Swapped a good working display with good DVI-D cable
- Tried CMD+Option+O+F my LCD idle light flashes from amber to green but after 2 sec back to amber (idle)
- Tried holding down power button for 5 sec and heard a tone sound + LED light flashes
- When i took the plastic cover off 1 Diagnostic LED turns red and the fan starts to run at full speed (which is normal)
- The fan runs at normal speed if the plastic cover is in place.
- HDD is detached but same issue when the HDD is in place.

Not sure if the internal CMOS battery is still good, but i don't think it will cause such issue right?

 

[photonorm]

overheating?

Are there any other LED lights deeper into the computer that you can see on when you are looking into it from the front? There is a LED that will come on when the processors are too hot. I am experiencing the same symptoms you are. However, I am working with a Dual 2.5 that is liquid cooled. I just did my second rebuild of the LCS and I can't get past the chimes and the overheat LED comes on.
If your machine is liquid cooled check for any coolant leaks.
I look forward to your future postings as we might be in the same boat.

You can read about my original situation at https://forums.macrumors.com/threads/1109014/

-Norm

 

[havokalien]

2.0 not liquid cooled

Try unscrewing and switching the processors. If it boots then one of the processors is dead. You will need ASD 2.5.8. Email me and I can help you there, I may even have a spare processor.

 

[hackerwayne]

Are there any other LED lights deeper into the computer that you can see on when you are looking into it from the front? There is a LED that will come on when the processors are too hot. I am experiencing the same symptoms you are. However, I am working with a Dual 2.5 that is liquid cooled. I just did my second rebuild of the LCS and I can't get past the chimes and the overheat LED comes on.
If your machine is liquid cooled check for any coolant leaks.
I look forward to your future postings as we might be in the same boat.

You can read about my original situation at https://forums.macrumors.com/threads/1109014/

-Norm

Thanks for the heads up, no over temp LED lights up. Everything is absolutely normal (Chimes, does PMU reset) except no display and doesn't do PRAM reset

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Try unscrewing and switching the processors. If it boots then one of the processors is dead. You will need ASD 2.5.8. Email me and I can help you there, I may even have a spare processor.

I do have some spare 2.3GHz processor around. (My side line is to repair, refurb and resell used/old Macs), not sure if they are compatible, but when i plug it in, Processor A and B Over Temp message came on (at this point, im 70% sure they arent compatible) but when i switch the 2.0 back, no LED lights up. Tried removing A and let B runs, vice versa. No dice. Currently the unit is still in my store room so i can do any kinds of test.