apc ups 6 kva issue

HI

I have a problem with an APC UPS 6kva showing an inverter problem with code 107 and p.13. find a circuit board issue, but I have no idea where to begin.

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crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0