Help!!! cMP4,1 won't boot.

[theone29]

Hi,
I have a 4,1 here that won't boot, powered on but then nothing on the screen. RAM light is not on, no beep or indicators. I tried resetting SMC, PRAM but there are no chime or sound coming from the internal speaker, visually checked the motherboard and cables connection, all seems to be good. Any suggestions, please. Thank you.
Specs: Single hex 3.3ghz, 12gb Ram, Dual 1TB HDD, flashed GTX 680.

 

[JedNZ]

Maybe replace the PRAM battery, the CR2032 or BR2032 I believe.

 

[bsbeamer]

What OS version?
Dual 1TB HDD in RAID for startup disk?

 

[theone29]

I'm going to grab a new CR2032 today. Regular set up on the HDD, I was going to install HS, update the FW to 5,1 then Mojave but I couldn't even boot to Recovery or Disk Option.

 

[bsbeamer]

Some people report needing to reset PRAM several times. Try a few times if it does not work immediately after battery replacement. BR2032 is the OEM part, but CR2032's do work (do not last as long).

 

[JedNZ]

I had an issue a year ago, and I finally resolved it by doing an SRC reset (Shutdown cMP - unplug power cord - wait 20 seconds, plus power cord back in - wait 10 seconds - power up), and then did a restart but held the power button down as if I was doing a firmware upgrade (I wasn't) - it made a bong noise and I then pressed the power button again which shut it down. I then powered back up and the problem went away. To me it kind of made it check itself. Might have all been in my head, but haven't had an issue since.