Cyberpower CP900EPFCLCD - F03 Error

[fmiku]

Hi guys,

Anyone can help me out to repair the UPS ?

I need to know the value of the 3 resistors or at least the operating voltage of the power supply (at the green arrow).

Thanks,

[Per Hansson]

Re: Cyberpower CP900EPFCLCD - F03 Error

You seemed to have identified the transformers windings in your post #60.
Just measure the same way on the PCB, and see what you have.
An example: the primary winding needs to measure open on the board now.
Same for the secondary winding(s)

[Shinjinkun]

Re: Cyberpower CP900EPFCLCD - F03 Error

Those components will not cause a short.
I would not power up without the transformer.
But do some ohm checks where the transformer windings was previously and post back the results.

Where should I make the measures? I attached the pictures of the pcb after removing the transformer to point it out.

[Per Hansson]

Re: Cyberpower CP900EPFCLCD - F03 Error

Those components will not cause a short.
I would not power up without the transformer.
But do some ohm checks where the transformer windings was previously and post back the results.

[Shinjinkun]

Re: Cyberpower CP900EPFCLCD - F03 Error

Those readings do not sound completely out of the ordinary.
What about the PCB right now with the transformer taken out, what do you read?
Still got any low readings? If so that points to something else being in short.

Yes, that's what I thought. I thought maybe the transformer was responsible for the short, but it doesn't look like it.

I haven't connected the PCB after removing the transformer, as I wasn't sure if I could do it or not... should I?

I am still concerned with the two components which we didn't have the value, the capacitor and the zener diode... I am using a 470pF smd capacitor and a 39V zener... could it have some relation with the short, or shouldn't have really anything to do with it?

[Per Hansson]

Re: Cyberpower CP900EPFCLCD - F03 Error

Those readings do not sound completely out of the ordinary.
What about the PCB right now with the transformer taken out, what do you read?
Still got any low readings? If so that points to something else being in short.

[Shinjinkun]

Re: Cyberpower CP900EPFCLCD - F03 Error

Ok, forget about the previous message.
Adding some extra solder, and moving the iron left and right, I was able to pull the transformer bit by bit, and finally removed it.
I attached the pictures of the transformer.
Then, I used the component tester with it.
If I measured between the first pin and the last one in the primary winding, I got an inductance of 11.1 mH and a resistance of 5.11Ω.
Doing the same with the secondary winding, I got 0.07 mH and a resistance of 0.16Ω.
However, when I tried measuring between the first, and two of the central ones, I got a value of 43pF and another with 36pF, like if they were capacitors... not sure why.
What steps should I do to test the transformer? Any tips?
Thanks again!

[Shinjinkun]

Re: Cyberpower CP900EPFCLCD - F03 Error

You can buy low temp solder, it is called chip quik:
https://www.digikey.com/en/product-h...um-solder-wire

Or you can get a vacuum desoldering iron if you expect to do more work in the future.

Yes, I have seen those vacuum desoldering irons before, but the cheapo ones doesn't look much better than the manual I have. The ones with electric pump, obviously better, are also fairly more expensive

Regarding that low temp solder, how does it work? Have you got an Amazon or Aliexpress link I could buy from?

Thanks

[Per Hansson]

Re: Cyberpower CP900EPFCLCD - F03 Error

You can buy low temp solder, it is called chip quik:
https://www.digikey.com/en/product-h...um-solder-wire

Or you can get a vacuum desoldering iron if you expect to do more work in the future.

[Shinjinkun]

Re: Cyberpower CP900EPFCLCD - F03 Error

Guys, I tried removing the transformer, but somehow, I can't get all the solder out of the holes, and when I try to remove it, is still pretty hard to move. Do you have any tips to take it off? I only have a manual pump, and some solder wick.

[Shinjinkun]

Re: Cyberpower CP900EPFCLCD - F03 Error

Hi guys! Sorry, I was off-line waiting for the devices I ordered.
Finally, I received a component tester, and also an oscilloscope (probably it will be helpful for the repair?). It is the model DSO-TC2 (https://www.aliexpress.com/item/1005004216333435.html)
I also bought an electronics starter kit that contains several resistors, capacitors and other components.
Then, what should be my procedure to continue with the repair? Remove the transformer and check its inductance? How do I know that the values are what they are supposed to?

[Shinjinkun]

Re: Cyberpower CP900EPFCLCD - F03 Error

Well you probably will not find that on sites like eBay, what you need is some basic electronic components.
They could even be harvested from some old PC power supply for example.

But ST also makes evaluation boards for their whole range of Viper chips and others, see attached PDF: STMicroelectronics Demonstration Boards.pdf
Sadly most of them are now out of production so the LED driver board linked below on Digikey was all I could find that looked reasonable.
That would get you the circuit in the attached PDF: VIPER22-LED-EV.pdf (the one on Digikey is the wrong schematic).

Or you could go the DIY route, I found this really excellent description at the site Circuit Digest below.
It should give you some ideas, but of course you then need to source all components by yourself.
But they do build a transformer too so that is very useful...

12V 1A Power Supply Circuit Design using VIPer22A by Circuit Digest:
https://circuitdigest.com/electronic...using-viper22a


Viper22A Isolated Outputs LED Driver Evaluation Board:
https://www.digikey.com/en/products/...-LED-EV/806368

Wow, that's a lot of info. Give me some time to digest this, please.
I just received the components kit I ordered a few days ago. I will see if I can try to replicate some of these example circuits.
It seems that there is still a long way to go... and I thought just changing the battery would fix the issue with the UPS

[Per Hansson]

Re: Cyberpower CP900EPFCLCD - F03 Error

Well you probably will not find that on sites like eBay, what you need is some basic electronic components.
They could even be harvested from some old PC power supply for example.

But ST also makes evaluation boards for their whole range of Viper chips and others, see attached PDF: STMicroelectronics Demonstration Boards.pdf
Sadly most of them are now out of production so the LED driver board linked below on Digikey was all I could find that looked reasonable.
That would get you the circuit in the attached PDF: VIPER22-LED-EV.pdf (the one on Digikey is the wrong schematic).

Or you could go the DIY route, I found this really excellent description at the site Circuit Digest below.
It should give you some ideas, but of course you then need to source all components by yourself.
But they do build a transformer too so that is very useful...

12V 1A Power Supply Circuit Design using VIPer22A by Circuit Digest:
https://circuitdigest.com/electronic...using-viper22a


Viper22A Isolated Outputs LED Driver Evaluation Board:
https://www.digikey.com/en/products/...-LED-EV/806368

[Shinjinkun]

Re: Cyberpower CP900EPFCLCD - F03 Error

There is not much use to test it without the transformer, the issue likely lies in or after it.
But sure, I don't think it would hurt, especially if you use the light bulb for current limit...


I meant that the tester can only accept 5v on its pins, so you need to be careful with it and discharge capacitors before testing, a rule that applies to all ESR testers really.

In order to build the circuit, can you recommend a starter kit with base components to do all these, please? I have been checking some arduino starter kits, but it seems that the breadboard that comes with is only up to 12V, so probably it won't be useful to do those tests, right?

[Per Hansson]

Re: Cyberpower CP900EPFCLCD - F03 Error

One question, if I removed the transformer, could I also reconnect the circuit and check if the short is still there, or should I try to avoid connecting it without all components? If I were to remove also the optocoupler and the capacitor between hot and cold sections, could I check the values? Or the circuit would be totally wasted?

There is not much use to test it without the transformer, the issue likely lies in or after it.
But sure, I don't think it would hurt, especially if you use the light bulb for current limit...

Yes, I didn't know such tester existed... in the end, I bought a new one that is a mix between tester and oscilloscope (that I didnd't have too).
What do you mean with the 5V? That the viper only handles 5V or you meant capacitors?

I meant that the tester can only accept 5v on its pins, so you need to be careful with it and discharge capacitors before testing, a rule that applies to all ESR testers really.

[Shinjinkun]

Re: Cyberpower CP900EPFCLCD - F03 Error

Well one thing you could do then is desolder the transformer and build a circuit from the Viper datasheet using it:
They do provide an example circuit in there for a charger...

Oh, I will try that. I think I am going to need a a starter kit of components, or disassemble a broken UPS I have in the garage. One question, if I removed the transformer, could I also reconnect the circuit and check if the short is still there, or should I try to avoid connecting it without all components? If I were to remove also the optocoupler and the capacitor between hot and cold sections, could I check the values? Or the circuit would be totally wasted?

And yes I meant to use the component tester for that, it is anyway a very useful tool to have.
Just remember to discharge capacitors before testing, maximum voltage it can handle is 5v!

Yes, I didn't know such tester existed... in the end, I bought a new one that is a mix between tester and oscilloscope (that I didnd't have too).
What do you mean with the 5V? That the viper only handles 5V or you meant capacitors?

[Per Hansson]

Re: Cyberpower CP900EPFCLCD - F03 Error

Well one thing you could do then is desolder the transformer and build a circuit from the Viper datasheet using it:
They do provide an example circuit in there for a charger...

And yes I meant to use the component tester for that, it is anyway a very useful tool to have.
Just remember to discharge capacitors before testing, maximum voltage it can handle is 5v!

[Shinjinkun]

Re: Cyberpower CP900EPFCLCD - F03 Error

Ok, I have been reading some info, and understand that those component testers are meant to check which type of components they are and their values. However, even if I were to check the transformer inductance, how do I know that the value is correct? Or just getting a value means it is fine?
So, in the end I found a component tester and ordered it from aliexp. I should get it in few weeks I hope.
By the way, I have been doing again another search for the service manual of the ups, but so far, I was only able to find a few cyberpower ups's, but different models, so they are not very useful (imho). Let me know if you get a hold of the service manual, please.

[Shinjinkun]

Re: Cyberpower CP900EPFCLCD - F03 Error

Do you have some way to measure the high frequency transformer?
I never tried but I guess even the cheap "component tester" project could get an approximate Henry reading from such a transformer.

No, I am not sure about how to measure the transformer... I checked the link you provided, but I am not sure about what to do with this... Am I supposed to buy these components? Or is is something that can be bough as is?
I get more and more confused by the moment... T_T

[Per Hansson]

Re: Cyberpower CP900EPFCLCD - F03 Error

Do you have some way to measure the high frequency transformer?
I never tried but I guess even the cheap "component tester" project could get an approximate Henry reading from such a transformer.