hi there.

I took before minutes one 'case' and if i cannot help i will close the device and give it back to client.

I see tracks are gone and there are 3 mosfets on heatsink. Without desoldering i see short in D-S in the two of the three.

If i replace the dead transistors and connect the broken tracks with wire what will it be?

thanks

 

From some of the black blocks on PCB and the components should be have some damaged, so before you checked all of the components on PCB to make sure they are all good, otherwise don't do power on.

 

A properly equipped and trained rework person could repair that damage. By that I mean replacing that section with another copper strip. Emergency repairs could be done with wires rated at the same current capability.

It's one thing if you did the repairs for your own equipment, but, for someone else as a professional collecting fee's for service, the risk can outweigh the rewards. Replacing can be less expensive than repairing, especially at that rated Power.

 

Emergency repairs could be done with wires rated at the same current capability.

How many ampers and wattage ?

can i use

https://i.ebayimg.com/images/g/nhQAAOSwNRlYJEOB/s-l300.jpg ?

I have here. WIll it lasts estimate long and what will goes on when the paint is gone?

 

Anybody ?

 

Without knowing the full circuit details of your device and the technical qualities of that liquid there is no way we can know the answers to any of your questions in post #4. So your guess is as good as ours.

 

post 1

 

post 2

 

I have one question. Where exactly to put back the pcb and the heat pad ?

https://drive.google.com/file/d/1PAfVNV4gN8Vnyc5aBR6m9zZbxPX4PO93/view?usp=sharing
https://drive.google.com/file/d/1Vthfutl9pPbpakIcEW8Usht1f9uyJzbw/view?usp=sharing
https://drive.google.com/file/d/1aW3UoeApghM3lnCeCUtZIz6h90zuJ65I/view?usp=sharing

thanks in advance

 

I have replaced the 2 dead mosfets with new ones. Have rebuild the tracks. Now when the device is in the mains it outputs Normal value voltage, but when take out the main voltage on the output there is nothing. The question is is the third one mosfet dead? I see no short G-D tested it with ESR meter out of the board and see no visible reason of failure.
I see advanced mosfet tester on http://www.4qdtec.com/mostest.html
but still don't have it. where I can normally find 10-100nF capacitors in devices because tomorrow is sunday and the market is not working?

I have tested all the basic diodes on the board without the zenners and all the NPN transistors. They are all fine. Can I test the LEG-12F somehow?

Thanks in advance

 

Now when the device is in the mains it outputs Normal value voltage, but when take out the main voltage on the output there is nothing.

Tell me all about the battery tests you have done.

 

JoeJester you want me to measure the battery voltage or?

what do you think about the version that this is from the ic with a lot pins?

https://forum.allaboutcircuits.com/attachments/20180822_124359-jpg.158495/

it`s cd4047be

 

Most of the times, when a UPS fails upon loss of power, it's because the battery is defective. I wanted to know the condition of the battery. I want you to measure the battery under a 0.1C load. If the battery is below it's 1.5V/cell limit, then recharge it or recondition it. More information about battery maintenance is found at Battery University.

If it isn't fully charged, per the manufacturer's specifications, then I don't know if the UPS was shut down due to low battery voltage or you have other problems.

What did you use for a load on your test of the UPS? I would recommend a 75W incandescent lamp, assuming you can find one.

 

Hi again. I am in the bus now. I just measured the output voltage with dmm.(output of the UPS!)
I dont know the reason of failure of device. I know the man is using it winter time. Maybe as backup for some heating devices

 

Measuring, for arguments sake, a 12V 7.5 ampere hour with a DMM having an input of 10M ohms isn't drawing much current (1.26 uA) from the battery. You need to load it down with a 0.75 A load. If the battery is bad, it will drop below 1.75V per cell very quickly. Your symptoms, after the replacement of components, acts like a bad battery. Once that is eliminated as the cause, then troubleshooting the circuit can once again begin.

The low element on a 1157 12V auto bulb will draw close to 0.7 amperes. That would make an ideal load to test a less than 10 AH battery. The high element will draw about 2 amperes and good for testing 20 AH batteries.

 

hi again.
i have nothing common with cars.
What is 1157? If i should borrow one bulb from someone known what to tell him for the bulb i need?
If i should buy something from the store i will of course.
The battery is "UL 7-12(12V 7.0AH/20hr)" if there are good and low quality pieces this is on "Ultracell"

I have here for Load 15W 1Ohm and 2.2Ohms and maybe someone other.

Thanks you lot.

I beleive that we will go to the truth/success.

 

7 AH / 20 hours is the current rating of the battery. your 1 ohm resistor would draw 12 Amps, your 2.2 would draw a little over 5 amperes. That is way more than a 0.1C load of 0.7 amperes. You could use either of those resistors, I would use the 2.2 ohms, as your test will only take a couple of seconds. Just monitor the voltage as you connect the resistor. If it drops below 10.5 V, you can recharge the battery and retest with the load. If it drops from the no load voltage of 12.6V to above 11.5, your good to try to see if the UPS works.

The best case is your battery is not defective but needs a recharge.

on edit ... I found the datasheet on the battery. It has the charging and discharging data.

 

it`s good to know that i have 3 LEDs indicators and only the red one(battery) is lighting.

I will measure the battery in minutes but am waiting for third and forth hand to appear near me

Ohh the battery has 10.800 without load

 

Recharge the battery in accordance with the datasheet.

Not with the UPS. Then test no load and loaded.

 

Can i just charge it in automobile