Tripp Lite 10kva UPS not going on

[drumow]

I have a 10KVA UPS. After a year it stopped keeping charge so I started a diagnostics as supplier and manufacture never got back to me. It has 20 12V CSB Batteries. I have checked all batteries and they mark 5V and less. I connected one to car charger left over night but same 5V. I Checked 3 random and all same problem so i decided to replace the batteries. After replacing the UPS seems not to be connecting to the battery pack so i decide to check the main unit. Inside was a very corroded so i cleaned and replaced a few ceramic capacitors that had its pins corroded. Now I am checking the components and found two SMD diodes that mark .0900 and i am going to replace but I can understand the reding can someone help me understand how to read them as been looking on forums and videos but can't figure it out. Attach please see the images of the diode I require to change.

Also attached picture of corroded components most them came good after a bit of good cleaning

Thanks

[drumow]

Re: Tripp Lite 10kva UPS not going on

I removed the diodes from the board and tested and the are marking correct. Anyone have an idea what I need to look for. I test all per transistors, all diodes and all relays. All seems good. The problem seems to come from when it needs to charge or use the batteries.

Thanks