Cyberpower cps1500avr not charging batteries

[carrzkiss]

Make and Model
Weepro vpro850L

Bought from Amazon about 6+ years ago.

[redwire]

At this point, I would say snubber capacitor C61 shorted which burnt up the resistor R42, which melted the relays. R42 would be like R48/C20, 680R flameproof.
The charging problem is not the burnt resistor, that is just to lower arcing on the relays when they switch. So I think there might be a charging problem despite the R42/C61/two relays. Hard to guess.
C29 top looks a but bulging compared to C26 right next to it, Su'scon 47uF 100V - which could mean the electrolytic capacitors are long in the tooth.

[carrzkiss]

These are two of the batteries that were last on the unit.
As you can see, they are right wrapped.

[carrzkiss]

I think the first image I sent was a trick of the light. They look the same.



The back of the board, in the red circled area, looks blackened. It does go over the area that has soot on it.


I'm not sure if this is anything or not, it looks like it was like this from the factory; the glue melted down.



Here is a better look at the back of the board. I brought the board over to my desk, where my studio light is, and was able to get a good solid picture.


This is the top of the right side of the front.

[harp]

Make and Model
Weepro vpro850L

Bought from Amazon about 6+ years ago.

Yes it is ok. I first time see dmm with positive lead on center, and negative on left side. That trigger me off.

I also shall add one things in my "honest" opinion: I was express myself regardless to your current input here; your conclusions, your question, your pictures and my base of experiance... but I want to notice that this count for that moment (start point) only, so it is up to you if you want continue with progress in that field or not.
Just that you come here to ask is good start point to collect various information about issue that help you in future to do some job done.

The "ink" on bottom is residue leakage from dissolved PCB compound cooked in high temperature (arcing), probably not from heating resistor only. This type of board repair I classified as advanced repair, because you have to completly rid off arc plague and rebuild any affected connection. But actual damage you cant see before desolder all arround that resistor.

I am interesting to see what type of soldering iron you have, what power, regulation, and with what tips (soldering tips various shape) you have for it?

And, have you familiar with measurement with dmm for sure, to can confirm or investigate where some track go, resistance etc...? Redwire have posted some information that should be confirmed by direct measurement.


EDIT
Yes, C29 is slightly bolged.

[carrzkiss]

redwire were you wanting the number for the three pins on the back that you wanted DC V from?
If so. This is what is on it

A VO VI (or) A V0 VI (hard to tell if it is an o or 0 zero)

[carrzkiss]

To answer your question, Harp, NO.
I never learned or had a need to learn much past battery testing and working on cars.
I sometimes break out my multimeter for my servers or within my network, but I have never sat down and learned hands-on with anything like what this thread is about.

[harp]

Ok, to start it is very usefull continuity mode, beeping mode. This is on oposite side from OFF position, like small WIFI simbol.

Be absolutely sure that the device under test is not powered on by any power source and discharged completly. This measurement is provided by dmm power only.

When you are in this mode dmm it will beep on any lower resistance, say any lower from 50 ohm or so, but on display you can see if it is direct line (all nulls 0.000 displayed), or it is something between probes, like 0.012... beep in both case, but in first is directed connection, and in second is ommited by something between.

You are interested in direct connection now.
So if you connect bare probes together, red and black, you will see 0.000 on displey, that means, that if you put one probe on leg of components, say resistor R42, you can pinpoint and trace where is this point else connected in circuit, just must see 0.000 simple as that.
Please try practice a bit and confirm if I am explain good?

[redwire]

redwire were you wanting the number for the three pins on the back that you wanted DC V from?
If so. This is what is on it

A VO VI (or) A V0 VI (hard to tell if it is an o or 0 zero)

Yes, that is the battery charger control IC and DC voltage readings on the 3 pins would tell if it's working or not. It's just an LM317 I figure.

When a gel-cell gets old, a cell will short out due to corrosion happening inside. So instead of a 12V battery, you have a 10V battery. This causes a big drain on the charger (i.e. because a 22V battery pack looks really dead) and it overcharges all the other cells trying to get it up to 28V.
So you get bulging, melted batteries, and a cooked charger circuit.


HEY based on the new pics, it is snubber capacitor C16 (not C61) in series with the burnt resistor R42. So I say this cap has shorted. But not the no-charging problem though.

[carrzkiss]

C16, OK.
I was trying to find the C61 and was having a hard time finding it.

I am going to send the pictures and information over to a local computer repair. He and his team are going to take a look at what I have and get back to me on whether it is something they can do or not.

I have been watching a lot of Video Game machine repairs and have a general idea of how to do certain things, but my issue is that I don't have the equipment to troubleshoot and test, so that kind of puts me out of trying to repair this unit on my own.

[redwire]

You have to figure out how much you want to spend to get it going again. Almost all of a UPS value is in its batteries. There's many dead at Eco centers, you could go fishin' but do the math they are rarely worth salvaging as all will need new batteries.

I think yours is repairable for under $20 in parts (plus new batteries). Desoldering parts is not easy, big through-hole parts can be no fun to desolder. It's really the labour costs and tools. Worst is there is no service manual or schematic for it, that complicates troubleshooting so many people would not be interested in fixing it.
How much is a new UPS 1,500VA with AVR?

I have recapped my old UPS and it still works. 99.9% of the time it just sits there and does nothing but the usual power glitch and it keeps my PC running. Needs new batteries every 5 years or so.

[carrzkiss]

I am going to send them over the information I have and go from there. I might just sit aside and wait on it until I have someone who knows how to work with these units.

I really wish I knew how to do it properly and had the equipment to work with them.
I will post back after I find out something.

[valvashon]

Look up the relays and see how they should be connected inside when they are not powered (in other words, what contacts are NO and what are NC. Measure with your ohmmeter before you unsolder any from the circuit. This is how I tracked down a bad/welded relay in a MiddleAtlantic 2200 (very similar device). It had different symptoms but you should search out my thread for tips on how to diagnose. When I unsoldered the relay the welded contacts let go and it measured continuity as it should but of course it was burnt up inside and couldn't be used again. This is why you measure before unsoldering. I ordered extra relays (I think that there are two different types in there) so if you find a bad one let me know and I will send you one if I have it.

Val