What if no CPU was under the heatsink?
I get a new board, power it up, none of the activity LEDs lights up. Hmm. Check power connection, everything is attached, but no activity, won't boot, won't reset, no output, not on the network. All the jumpers firmly seated. Swap SODIMM module and mass-storage for known-working, no joy.
I'm just about to pack it up and send it back when I wonder, is there actually a CPU on this main board? What if nothing is under the heat sink? Get out the iPhone, compare pictures of this never-worked board with a previously working board.
Oh! The working board has a visible chip carrier, the non-working board does not. I can see the interconnect pattern the carrier *should* be soldered-to on the non working board. Not on the working board.
Visual inspection agrees with behavior- No CPU! I send it back, the supplier confirms, yep, no CPU! Well, there's your problem!
What if no CPU was under the heatsink?
I get a new board, power it up, none of the activity LEDs lights up. Hmm. Check power connection, everything is attached, but no activity, won't boot, won't reset, no output, not on the network. All the jumpers firmly seated. Swap SODIMM module and mass-storage for known-working, no joy.
I'm just about to pack it up and send it back when I wonder, is there actually a CPU on this main board? What if nothing is under the heat sink? Get out the iPhone, compare pictures of this never-worked board with a previously working board.
Oh! The working board has a visible chip carrier, the non-working board does not. I can see the interconnect pattern the carrier *should* be soldered-to on the non working board. Not on the working board.
Visual inspection agrees with behavior- No CPU! I send it back, the supplier confirms, yep, no CPU! Well, there's your problem!