Power Mac g4 will not power up

1st...thankyou for responding. I am new to MAC, this is my first time diagnosing such a severe issue. i.e. "Power On Button above mirrored doors will not light at all".

1- Located Ser # & site where it is entered...Have all info. you asked. I will check your site suggestions w/ser. #.

Group: PowerMac

Family: 8570, Model : 8840

CPU speed: 1.25 Ghz

RAM: (2) 512 sticks S1 & S2

Production Yr: 2003

2- NO LED on board. motherboard has 1 reset button labeled "PMU" (Have pushed & held it)

3- Have completed Reset of Logic board suggestion, still "won't power up, no fan movement"

4-Have removed ALL modules from MB: 1 module at a time, all the way down to NOTHING, (not even P1 from PSU connected) then plugged in each module...the front Pwer Button still will not illuminate.

5- PSU, P1 connector: In off state, AC power applied, I found only 1 connection haveing 25.5VDC?

Will check & 95038 & TS1367

6- Where can I locate details of P1? ie Pin out with expected voltages especial under AC pwer, static state?

I shall return!

Okay...

Unit sat overnight unplugged.

-PMU reset performed....

-Power ON button illuminated ! ( I am back to 4 days ago)...

1- display of gray apple screen (attempted Command & S , then Command P & R (apear to NOt have initiated anything different)

2- display of blue screen, with mouse pointer (mouse did move pointer)

3-Now mouse gone, unit is at Blue Screen with circular line indicator.

Power is still on....Do you know how to get out of this screen?

Just as earlier...

-Power ON, while lit...does not respond to 10 second hold for forced reboot.

Q: Command & shift key ?

Also...using an IBM keyboard...so.."the windows" key = to "Command" key?

Only way to power unit down is uplugging it.

-Addtional notes:

1- a single chime over speakers was heard

2-If I unplug unit....I will be back to the begining

Any other way to over ride & shut down machine...reboot?

Opening case while in this blue freeze, spining indicator state, I locate the on board LED.

It is on, glowing red.

It is located ajacent to the NVRAM sticks.

Progress!

Performing a PSU button reset, battery removal w/10 minute wait perion, then PRAM resest....make AC pwr connection....

Results in repeatable re-boot! NOTE: makes audbile "ta-da" chime each boot

Okay...I am holding shift button, now 2 reboots no change 😟

Gray Apple Screen, then blue screen with spinning indicator.

This second time...Mouse did not initiate?

(side note: using tool to depress shift key while I am typing)

At this moment: Shift key depressed, (at Reboot), blue screen has spin indicator...

Q. Is there a way to reboot to CD player? & a utility I could burn to disk ???

Thanks for help: BD Aqua & Tex M M

To any one, Moderator, or others,

If I can get this machine to "Repeated-ly" reboot...

Even to blue screen....etiquette wise...should I close the question as solved?

Lets say moving on to a new question....How to get beyond the Blue Screen with spining indator?

Or....How from a cold state..do you force Mac G4 to boot to a utility disk?

Please advise....

Thanks

Nick