Quote:Do you have L1 console output that suggests you have a dead battery? On that RTC? For that matter have you checked your yellow snaphat battery as well (much more likely to be dead). Does your L1 output during start suggest it’s defaulting and filling values after checksum errors or encountering bad values?
Yes, in case of NVRAM chip with dead battery the L1 is complaining about NVRAM checksum so here I assume in this case it's reinitialized from the Atmel EEPROM. The snaphat battery is fine (I suppose it's not even used in L1).
Quote:Otherwise, the reason I have trouble with this theory is, you claimed in your description that if you leave the Fuel off and then try to start it you have to cycle 5v power to get it to start.
This is when I leave the Fuel off with PSU disconnected from mains. Then I have to power cycle the 5V standby rail in order to start L1 and the machine. If I leave the Fuel off with PSU connected to main then the 5V standby line is still on and I can power on the Fuel without any problems - this is because the L1 is initialized and running.
Quote:Now I assume you meant this literally, like you have a running Fuel after your fiddling, you say shutdown in the PROM or Irix and it does so. Then you leave it alone and do not actually cut PSU AC power, so 5v standby has been feeding the RTCs all this time. Yet you still have power on issues on your next attempt?
Already answered above - no, there are no power on issues in this case.
Quote:The L1 RTC (for sure, not sure about snaphat, but likely the same) battery is for when the board doesn’t receive 5v. Which would only happen if you actually pulled AC wall power between system startups.
Agreed.
Quote:Please clarify startup testing procedures.
I'll do so verbatim:
- the Fuel is disconnected from AC, I plug in the L1 console cable
- the Fuel is connected to AC, the power on button doesn't work, no L1 console output
- reconnecting AC cable doesn't help - this is very likely caused by PSU capacitors not resetting L1
- this is the point where I power cycle the 5V AUX rail by unplugging the 24pin ATX-like power supply connector from the motherboard
- if the above doesn't help to get L1 console output, I repeat
- now I have L1 output and can power on the machine
- until I unplug the AC cord, all consequent power on attempts are without any issues
