Cpu 43412a Not Booting

Hi Every Body
We Have Got Some Problem In The Cpu 434312a Which Is Not Booting And Effecting Other Modules Also (due To This Cpu Other Modules Also Not Booting).
But If I Remove And Insert It With The Powered Back Plane Then Everything Is Ok.
I Even Tryied By Loading The Latest Exec File In The Cpu.

I am confused.
You have a Quantum CPU43412A which is not booting.
You remove it from the rack.

Then what do you do?
If you remove all of the other modules in the rack, what does the CPU do?
What lights do you get on the CPU?
Is you power supply sized large enough for all of the load in the rack?

If the processor is giving an error code of 8 blinks it may be a unit that is affected by manufacturers defect (substandard power supply components as I remember). There was a batch of 434 12A processors that had defective components in them but Modicon refused to do a recall. Info is available from Modicon as to which serial number ranges are affected. I had one that took two days of frustration for me to figure out. It had a tiny program in it for months and worked fine. When the program grew it started crashing after a few seconds once powered up. The Modicon help person finally remembered "something about the code of 8 blinks". The resolution was to send the processor to Modicon for repair.


Steve

Cpu 43412a Booting Problem

Thanks For Your Reply
Actually This Cpu I Used In The Hotstandby System So It Was Running And For Some Reason We Powered Off The Back Plane And Again Powered On But This Time We Saw The Cpu Was Not Giving Any Led Indication Same Situation With The Rio Head And The Chs Module But The Strange Thing Is We Have Noe Module In The 5th Slot And It Was Giving Led Indication...the Power Supply We Used Is Cps 124 20 Which Is More Then Sufficient For These Four Modules I Believe.
But At This Stage If I Remove Cpu From Backplane (as Back Plane Is Already Powered On) And Insert It Again Then No Problem At All (once I Remove Cpu The Other Modules Start Giving Indications) That Means Cpu Also Get Ready ...
I Already Checked The Backplane And Power Supply With Other Cpu Its Working Fine The Only Problem I Guess Is In The Cpu Only.

How fast are you cycling power to the CPU. Many processors do not like to see power come back on before they have completed their power down procedure.