No signal for hdmi and DVI ..

Hi!

Please help!  Mac Mini 2012 Late, A1347 (820-3227) looking for the answer .. Turns on, startup sound is on, fan is on, USB powered (even router LAN network can be seen in Apple ) Problem with no picture, no hdmi output, no DVI output none  .. I disassembled it but based on the motherboard measurements everything “looks good”.  I suspect the PS8401A ic error .. Got new flash and memory ic, situation is unchanged, unfortunately nowhere can I find circuit drawing, not even in paid places.

 I looked through the sheet, I didn't find a burn short circuit.  

(Test trial of two working hdmi and one DVI cable and trial of three monitors and one tv)

Thanks in advance!

Joeteso