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Old 04-07-2021, 10:31 AM   #1
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Join Date: Dec 2019
City & State: Windsor, Ontario
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Default A1418 820-00431-A Looping LEDs

Hello. Attempting to repair 2 different logic boards with i5 CPU + 8GB iMAC A1418 2k.

Each shows the first bottom LED on = power supply is good.

Power button is pressed -> LED 2 and then LED 3 each turn ON and then reset and recycle to only LED 1 (power supply) ON.

Checked against another logic board and found that inductor linked to FDMF6808N near CPU is @ 12.x Mohms.

Yet, on the board with the 'power cycling' is @ 2.x Mohms or lower.

Should FDMF6808N be replaced? Found some @ MobileSentrix. Weird that ONSEMI / Fairchild is not showing this component.

Is this an EOL component?

Welcome any suggestions for this repair. Now also have the DS-809SE tool as of yesterday. Should be able to read out the flash firmware for public posting.
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