LM5170EVM-BIDIR: boost only operation

I am trying to use the LM5170EVM in boost mode only with Vin = about 15 V and Vout = the default value in the EVM (about 50 V)

I shorted the breaker FET drains with a wire while the circuit was powered up to remove them from operation.

The outer voltage loop does not appear to be controlling the output voltage now; the output voltage is over 60 V and the circuit is hiccupping (I presume because OVP is being triggered).

I have a 3 A supply powering the converter and it is indicating OCP during the hiccup events.

Please suggest what I have probably damaged on the EVM to cause this behavior that the HV output is not regulating at about 50 V.

The EVM now powers up into the hiccup mode without the need to short together the drains of the FETs.

Should it be OK to not remove the breaker FETs but to just short the drains together.

In a closed thread "LM5170EVM-BIDIR: BOOST doesn't work but nFAULT is HIGH" Youhao Xi advised to do the following to operate in boost mode only.

• Remove the four breaker FETs (Q5, Q6, Q8, Q9)
  • The gate drive signal will not be present without the HV output voltage present at start-up
• Solder a short across the drain pads of the removed FETs
  • Connects the LV input to the boost circuit
• Short J3 (SYNCR)
  • Disable FET checking at start-up since breaker FETs are replace with a short
• Short J35 (V12)
  • To provide an input signal for the outer voltage loop
  • QUESTION: should this be short J34 (V48) and open J35 (V12)

I made the following jumper changes to the Table 2 (page 7 of EVM User Guide)

1. J21: 1-2 shorted, 2-3 open; 12 V is present on EVM, 48 V is not
2. J28: 2-3 shorted, 1-2 open; set direction for boost mode
3. J30: 2-3 shorted; did not want CH2 running on first power-up

I made the following jumper changes to the Table 3 (page 8 of EVM User Guide)

1. J3: shorted; disable FET fault detection at start-up, breaker FETs do not need to be checked
2. J4: shorted; use the on-board DC/DC as the Vcc supply
3. J6: shorted; as specified in the table, but this DISABLES the ISETD function (the table says it enables the function)
4. J34: shorted; intention is to enable 48 V input to outer voltage control loop, see comment above regarding recommendation from Youhao Xi 
5. J35: open; intention is to disable 12V input to outer voltage control loop, see comment above regarding recommendation from Youhao Xi
6. J36: shorted; to use analog outer voltage control loop
7. J37: shorted; provides power for analog outer control loop circuits

Rather than removing the breaker FETS, I left them on the PCB and shorted the drains together with a wire after the circuit had been powered up (did not follow directions from Youhao Xi )

My board powers up but it appears the outer voltage loop is not working because the HV voltage is over 60 V and it appears the circuit OVP is kicking in and causing the circuit to hiccup with the drain shorting wire not present, even after cycling the input power.