I've an UPS but it's not working fine. Disassembled it a bit and tested components that I could without unsoldering, everything seems good. Then the problem is :
-
Normally I should be able to connect the batteries and the UPS would just be in "sleep" mode, the screen would be fully light up but the UPS should be off
-
The problem here is that firstly when I plug batteries the fan turns on, it should not and only turned on when on batteries but when the UPS is on
-
The second problem is that the screen doesn't work as intended. This is a screen that has prewritten zone that just have to be lighted up (don't know the name of this kind of screens, the type like in digital clock), here only the backlight is lighted up (normally all the possible drawing are lighted up too), but quickly it begins to drop in lightness to turn black at the end (the fan continues running)
Check the batteries they are 2 x 12V at 12.6V here
Thanks for your answer
EDIT : on the photo the two blue and brown cable at right are the power plant electricity going to the UPS
Depending on the meter and your approach it can be either safe or lethal. The more I think about it, the more I'd recommend that you just don't do it at all. Working on 240V installations under voltage, that is something we teach electricians to do safely. Besides the training it involves some special and rather pricey equipment.
I cannot stress this enough, if you mess up, you will hurt yourself with enough severity that the can easily be fatal. If you don't know what you're doing, messing up will be exponentially more likely.
Desolder the transistor, does the rest of the board light up? If so replace the transistor. Otherwise, get trained assistance on person or replace the UPS. I'm all for learning electronics, but not on a live UPS.
Thx for the advice, gonna check the transistor
And I think that my meter is capable of 240V but gonna inspect it with help of electricity guy
It's not a matter of whether your meter can do 240V, can you do 240V? Because that can be the consequence of slipping with the probe.
Sorry, I don't mean to come off all aggressive. I just want to make sure that you don't hurt yourself because I wasn't very clear in my communication.
Ohh okay don't worry for being too "aggressive"
Thank you for saying out the risks for people like me who doesn't know that much in electricity
And thank you for your answers