HMI repair and illogical zener configuration

[mnt22]

Hi everyone, this HMI flickered then the magic smoke come from it.
I track the input voltage on the pcb all good to the td1501sadj buck converter output, what confused me is the burned zener diode with zero ohm resistors!, and I found burned chip witch i can't find datasheet for it (U6) (1102A/AAC?),
I need some help finding datasheet for it and (U9) (gh158/502MI) also I wonder why and how zener with zero ohm!.
Thanks everyone in advance

[Paul Moir]

It looks like the 0 ohm resistor disconnects the power supply from the rest of the circuit.  It may have been intended for troubleshooting, or a place for a flameproof resistor fuse.   The zener diode was to protect against over voltage from the supply but it burnt and failed open.  Likely that other chip died next.  There could be more carnage on that rail  There may be more damaged devices that are supplied by that power supply.

[mnt22]

Unfortunately the zener diode failed to 4 ohms and wreaked havoc on the chips 

[floobydust]

Possibly SCM1102A PWM controller, it needs an external mosfet switch.
AAT1102 boost-converter SMT marking code is 1102 MAAC, OP has 1102 AACB.

[mnt22]

it turns out U6 is AAT1102 (ADVANCED PWM DC-DC CONVERTER WITH  INTERNAL SWITCH AND SOFT-START)
as MULTIPLE-OUTPUT TFT LCD POWER SUPPLY