Cyberpower PR1500 won't charge battery

[budm]

Re: Cyberpower PR1500 won't charge battery

D23 should be Zener diode, as you can see, D25 is the rectifier for the converting AC of the AUX winding of the transformer to DC, the Cathode of D23 is connected to the VCC pin of that SMPS IC, the Anode of D23 is connected the hot side circuit GND, the Cathode is connected to the VCC pin of the SMPS ic. The circuit is working otherwise you will not be getting and DC on the cold side. D23 is just the protection diode to clamp the VCC in case the VCC goes higher than the the rating of VCC.
When you make Voltage measurement in the HOT side, you do use the negative leg of the main filter cap as the GND ref. for the meter.

"I suppose I could try firing up the circuit with the diode removed, as it is now and do some measuring. What do you all think?" I thought that is what you did to get the 30V reading on the cold side since your pictures show D23 is not installed.

[reberhar]

Re: Cyberpower 1350AVR won't charge battery

Hi All,

I borrowed my wife's Nikon. Here are a couple of hi definition fotos.
Because of what I see on the 1500 schematics I am thinking that the diode I need to replace D23 might be an HER305 or maybe a 1N4148.

The voltage to earth ground runs maybe 168 Volts after the choke, 1N4007 diodes and the caps. However in this case earth ground is not the real reference for these diodes. At the negative connection of the filter cap, to the shorted diode I got 0 volts, go figure. I suppose I could try firing up the circuit with the diode removed, as it is now and do some measuring. What do you all think?

Roy

[reberhar]

Re: Cyberpower 1350AVR won't charge battery

Hi Budm,

First I was wrong, the little 22uf cap does not feed D23. It connects directly to the transformer feedback winding as in the pdf I included.

And I hope you have open office or libre office. I annotated the photos with their draw program as I use Linux.

One more thing. I apologize for the fotos. I tremble. I spent an hour trying to get acceptable ones. I hope these are ok.

Roy

[jr219]

Re: Cyberpower PR1500 won't charge battery

The charger is always on without the need to turn on the power switch. So the charging output is steady at 35V without batteries instead of around 55V.
I would try changing that C42 first since it is easy to do. The problem can also be the due to faulty regulation feedback that keep the output Voltage to be that low. You did verify that the rectifier and the filter caps on the cold side are good, correct?

I can do that. I haven't tested anything further. Forgive me, but I'm more of a software and digital guy...

If you let me know what I would need to test (ie: look for chip x, which should run to cap X and measure the output, etc) I can do it and report back.

thanks,

-jr

[budm]

Re: Cyberpower PR1500 won't charge battery

The charger is always on without the need to turn on the power switch. So the charging output is steady at 35V without batteries instead of around 55V.
I would try changing that C42 first since it is easy to do. The problem can also be the due to faulty regulation feedback that keep the output Voltage to be that low. You did verify that the rectifier and the filter caps on the cold side are good, correct?

[jr219]

Re: Cyberpower PR1500 won't charge battery

Getting 35V where? What did you use for GND ref. for the meter?

This was between BAT+/BAT- with the UPS plugged in but not turned on. It will *not* turn on without batteries (but it will stay on if you remove batteries from it while in AC mode)

[jr219]

Re: Cyberpower PR1500 won't charge battery

BTW: "but is only outputting about 30V when plugged in." Is that WITHOUT the batteries connected?

Yes, that is with no batteries connected.

I'm getting about 35VDC on the BAT+/BAT- terminals. I am thinking that I need to be getting ~55V to charge them. 48V batteries.

-jr

[budm]

Re: Cyberpower PR1500 won't charge battery

BTW: "but is only outputting about 30V when plugged in." Is that WITHOUT the batteries connected?

[budm]

Re: Cyberpower PR1500 won't charge battery

Thanks. Bud!

For mine, I'm getting 35V.. I don't know if the others were getting 0V.

So I should replace C42? What about the others? In previous posts, you mentioned replacing a few others while the board was out?

I realize the schematic mentioned earlier doesn't line up exactly.

I have a scope and talking to another friend of mine who looked at the schematic, he had me look at pin6 of the 3845B and I did get a square wave out of that.

Thanks again for your help.

Getting 35V where? What did you use for GND ref. for the meter?

[jr219]

Re: Cyberpower PR1500 won't charge battery

C42 in the hot side is the startup running cap.

Thanks. Bud!

For mine, I'm getting 35V.. I don't know if the others were getting 0V.

So I should replace C42? What about the others? In previous posts, you mentioned replacing a few others while the board was out?

I realize the schematic mentioned earlier doesn't line up exactly.

I have a scope and talking to another friend of mine who looked at the schematic, he had me look at pin6 of the 3845B and I did get a square wave out of that.

Thanks again for your help.

[budm]

Re: Cyberpower PR1500 won't charge battery

C42 in the hot side is the startup running cap.

[jr219]

Re: Cyberpower PR1500 won't charge battery

I need straight shot looking down to the left of the transformer, the pictures you show is in the cold side, I need the pictures of the hot side.
Straight shot of the whole board will help.

Let me know if these or you need additional ones.

C40 on mine is not axial?

[budm]

Re: Cyberpower PR1500 won't charge battery

I need straight shot looking down to the left of the transformer, the pictures you show is in the cold side, I need the pictures of the hot side.
Straight shot of the whole board will help.

[jr219]

Re: Cyberpower PR1500 won't charge battery

Here are some photos of the board I am working with. I'm trying to identify the charging circuit, I believe it is in this area. I assume that the component numbers (C40) might not be the same, but the components are, or I can trace them from another component somehow?

Thanks for any advice!

[jr219]

Re: Cyberpower PR1500 won't charge battery

Thanks for this thread. I have a PR1500LCDRT2U, which is no longer outputting high enough voltage to charge the batteries. Has 4 batteries in series, but is only outputting about 30V when plugged in. This results in the batteries discharging over time and the unit failing to turn back on.

I've been reading through this thread and found many discussions about a replacement of some caps (C40?). My board seems to be a bit different than the ones discussed here.

I'll likely be back with some photos and seek advice on replacement parts?

-jr

[budm]

Re: Cyberpower PR1500 won't charge battery

Better pictures needed.

[budm]

Re: Cyberpower PR1500 won't charge battery

https://www.badcaps.net/forum/attach...3&d=1524864384
The picture is not in focus.
Looking at your pictures this is what I see:
1) D3 in the spec sheet is D25 in your board which is the rectifier for converting AC from AUX winding of the transformer to run the IC once the circuit started.
2) D23 on your board looks to be connected between VCC pin of the IC and GND, please verify. If that is the case then it will be Zener Diode for Over Voltage protection (OVP).

[budm]

Re: Cyberpower PR1500 won't charge battery

Can we see the whole top and trace side of the board?
I cannot tell using your pictures in your post 69 to figure out the circuit where D23 is actually used in the circuit.

[reberhar]

Re: Cyberpower 1350AVR won't charge battery

Hi Guys,

Although I don't have schematics for my CyberPower 1350AVR I have found a diagram that approximates the circuit I am working on. I need to understand the VIP22A which really handles the charging. Like the 1500 units my batteries are not charging either. I have replaced the VIP22A which was burned and a burned out fuse but still no joy.

There is a link to the document with the diagram that has been helpful to me.

https://cdn.badcaps-static.com/pdfs/...4d8ae765c7.pdf

On operations 4, 4.1 of that document the corresponding diode to my unit is D3. It is shorted. It is D23 on my attached pictures. I have attached some photos of the diode too. It is fed by a 22uf 50V cap that I have ordered.

This diode is a really tiny glass case unit. I am going to try to get a powerful magnifying glass to augment my shop one which is indeed powerful. So my problem is that I can't read the part number. I am studying the 1500 schematics for an idea.

Many of you are much much better techs than I will ever be. Your suggestions are desired and welcomed. What do you think it might be?

Thanks so much,

Roy

[budm]

Re: Cyberpower PR1500 won't charge battery

@13.5mA means it is not being charged at all, it may mean that the charging is not working at this point, it can put out 27.8V with no load but not with load (Batteries) connected.
9Ah will have longer run time than the lower AH.
You can try connecting 40W lamp (it will have cold resistance about 24 Ohms, hot resistance of 360 Ohms) in place of batteries to draw about 1A and see if the output Voltage of the charger will be around 27V or not.