Cyberpower BNT-600AP UPS

[zero00]

Hello everybody.
I have very interesting issue. Six months ago I have replaced battery in Cyberpower BNT-600AP UPS and everything was working OK. Few days ago i noticed that UPS won't hold when is switched to battery mode.
What I was noticed that I have open device is that C18 was bad. I have replace it, but i still have same issue..

I have tested battery, and it is OK. I have used another one with same result. IN the end i used DC power, and with 12V i have exact same behavior as with battery. When i change voltage to 13V, UPS can hold low power device (up to 5W)..

My understanding is that problem can be related to part who is responsible for checking of battery state.. I'm thinking to replace also LM324N and LM317.

Did somebody had similar issue? Any opinions about this situation? Thank you..

[sam_sam_sam]

Re: Cyberpower BNT-600AP UPS

Are you sure that you do not have problems with the micro controller ic chip because the chip you are referring is connected to and it looks like this micro controller ic chip controls the charging function

I am not sure how you can check and see if the micro controller ic chip is working correctly

Me personally I do not know if I would spend much time trying to fix it

[budm]

Re: Cyberpower BNT-600AP UPS

Do you have the rest of the schematic?
Without battery connected, what DC Voltage do you have on the Red and Black wires when you plug UPS into the AC outlet?
Fuse F1 is good?
What is connected to connector CN2-4, CN2-5?
Q21 is connected strangely.

Be careful not to touch the conductors when making the measurement since the charger circuit may not be isolated type.

[zero00]

Re: Cyberpower BNT-600AP UPS

Do you have the rest of the schematic?
Without battery connected, what DC Voltage do you have on the Red and Black wires when you plug UPS into the AC outlet?
Fuse F1 is good?
What is connected to connector CN2-4, CN2-5?
Q21 is connected strangely.

Be careful not to touch the conductors when making the measurement since the charger circuit may not be isolated type.

1. No. That is all that i have. Except transformer everything else is at schematic.
2. I have to double-check, but i think that i had 13.7V
3. Yes. Tested.
4. I have to check.
5. Please can you explain in your opinion why is strangely connected?

Thank you..

[zero00]

Re: Cyberpower BNT-600AP UPS

Are you sure that you do not have problems with the micro controller ic chip because the chip you are referring is connected to and it looks like this micro controller ic chip controls the charging function

I am not sure how you can check and see if the micro controller ic chip is working correctly

Me personally I do not know if I would spend much time trying to fix it

I'm not sure that micro-controller is not issue. At this point i think that reading of battery level are wrong.
I ordered few components that are in my opinion problematic, and i will check.

Thank you..