Anyone know how to repair a UPS?

taz420nj

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Ok so I ran into an issue today. The power flicked out a couple times then came back on (this has happened a few times in the past month, and according to the guy at the power company it was a breaker tripping out and resetting due to a fried critter).. When it finally stayed on, I could hear the constant buzzer from the UPS, and it was showing overload. I shut it off and turned it back on, things started up normally. It was only showing 280w load (it's a CyberPower OR1500LCDRM-2U, 1500VA/900W, so nowhere near the rated limit). I pulled the plug and it went into overload again. On utility power, it starts up and runs just fine with all loads. With no loads connected it will cold start off the batteries just fine, but plugging literally ANYTHING into it while on battery shuts it down. Even a wall wart.

My first thought was the batteries are getting some years on them and maybe starting to lose capacity, but I just did a runtime test a couple months ago and it went for about 65 minutes before the low battery warning with the same loads connected (the server which pulls about 200W shuts down at 90%, in order to maximize time for the network gear, but avoid shutdowns for blips and short outages since it has to be manually turned back on).

Then I thought I might've yanked a battery cable loose from the pack (4x batteries, 2x 24v series in parallel) when I moved it recently, but again it's not complaining about low battery, it's tripping into overload.

So now I'm thinking this quick set of on/off cycles might've surged it. I opened it up and don't see anything burnt up, no fuses blown, but it's been about 25 years since electronics class. Since I am able to cold start it with no load, I did that and let it run just to see what happens, if nothing else it'll recalibrate the runtime meter, and it has actually been running for over 5 hours now before the low battery warning just kicked on. It's still at 10% so it'll probably go at least another half hour or so before it shuts off.

I'm assuming there is something going on with the inverter circuit since it passes power on utility. Any ideas where to start? I have a multimeter and an oscilloscope if someone is familiar with the inner workings of these things and can offer guidance... I really don't want to have to toss it, because I don't want to have to spend hundreds of dollars on a new one.
 

myipcam

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This maybe a simple or complicated fix. From the incident you described, it could be n number of things. First thing I'd try is to get a known, working battery. Just read 24v (edit) get couple car batteries fully charged and hook it up and see if the behavior is same.
That's where I would start.
 

bp2008

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Man I feel your pain. Good UPS devices are expensive despite being very old tech now. I have one of the $180-ish Active PFC units that stopped working a couple years back and new batteries didn't help it. I already put more time into it than it is worth.
 

taz420nj

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This maybe a simple or complicated fix. From the incident you described, it could be n number of things. First thing I'd try is to get a known, working battery. Just read 24v (edit) get couple car batteries fully charged and hook it up and see if the behavior is same.
That's where I would start.
As I said that was my first thought, but at this point it's almost guaranteed not to be the batteries. It wouldn't even run with a couple hundred milliamps from a wall wart plugged into it - if the batteries were that bad, it wouldn't have run for 6 1/2 hours under its own inefficiency. I load tested them and they measured 25.5v on each set while it was running.

Man I feel your pain. Good UPS devices are expensive despite being very old tech now. I have one of the $180-ish Active PFC units that stopped working a couple years back and new batteries didn't help it. I already put more time into it than it is worth.
Considering I spent over $500 on it (granted 8 years ago), and it'll cost $400 to buy a new one of the current model, I'm definitely not there yet lol, especially if it turns out to be a simple bad component that costs a couple bucks and takes half an hour to replace. That I can do no problem, I just have no idea where to start as far as testing/diagnosing to figure out what is actually bad. So ideally I guess I'm hoping someone either has or knows where I can find the service manual. I know there are some Cyberpower ones out there, I just haven't found one that relates to this unit.
 
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myipcam

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I could only guess but usually, cheaper (as most of them are made nowadays) capacitors start to leak internally as they age. The windings enamel may give up but that's usually the last. Solid state should last if operating under parameters (again, quality)..
 

myipcam

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Well, first you start with 24v going in and start tracing to see what voltages are seen at different places. Usually, to get 110vac, it is either a square wave or sine wave oscillation. OTH, you could go backwards from the primary windings of the 110v output transformer and trace it to either switching power transistors or MOSFETs. You could google the parts and see which ones... lastly, without a schematic, it could be a bit difficult especially without strong electronics experience. Frankly I would be in about the same position as I am not that experienced either. Just some troubleshooting here and there...

Just be careful around the secondary side.. high voltage and all..
 

bob2701

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If you haven't replaced the batteries in 8 years look no further. They are only rated for about 3-5 years.
 
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but it's been about 25 years since electronics class
it could come back to you, but the challenge would be getting your hands on a schematic for that device. You could reach out to CyberPower, see if they offer out-of-warranty service options, or could hook you up with a schematic. Most companies don't have any good reason to help you work on these devices yourself (for many reasons including the legal risk of a faulty repair leading to something catastrophic), and schematics are usually tightly controlled. But if you can reach out to a tech there, my experience with electronic circuits is the failures typically fall in a few well known failure buckets, meaning a good component level tech could shotgun the right answer 80% of the time with just the symptom. There will always be a couple oddballs that are intermittent or you wouldn't ever figure out because they are one-offs, and component level repair isn't popular because of the cost of spending electronic technician time on the repair adds up quickly, so YMMV. (Meaning if they have "repair techs" that swap boards you are probably SOL).

Personally I would replace the batteries because of age, but it does sound like your problem is probably related to inverter (since that should be the circuit that's generating your AC when operating from battery). A local electronics repair shop might even be able to help troubleshoot without a schematic because so many electronic circuits are similar to one another. I had a tech showup to repair a big screen once (cant recall the brand), but anyway he said it was the first one (of that brand) he'd had to fix, which made me wonder how he could possibly know how to troubleshoot it, but turns out TV circuit boards are more alike than different in how they function (apparently). Maybe you get lucky and UPS is the same way.
 

myipcam

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Is there a way you can load test those batteries? You could take it over to Autozone etc., and see if they would hook up their load tester. OTH, you can (assuming it is two 12v batteries in series) hook up a 12v headlight (halogen type) to one battery at a time and see how long it runs and calculate run time based on amps drawn and the rated capacity of the battery... see if they match. You will know for sure if the battery is good this way.
 

taz420nj

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it could come back to you, but the challenge would be getting your hands on a schematic for that device. You could reach out to CyberPower, see if they offer out-of-warranty service options, or could hook you up with a schematic. Most companies don't have any good reason to help you work on these devices yourself (for many reasons including the legal risk of a faulty repair leading to something catastrophic), and schematics are usually tightly controlled. But if you can reach out to a tech there, my experience with electronic circuits is the failures typically fall in a few well known failure buckets, meaning a good component level tech could shotgun the right answer 80% of the time with just the symptom. There will always be a couple oddballs that are intermittent or you wouldn't ever figure out because they are one-offs, and component level repair isn't popular because of the cost of spending electronic technician time on the repair adds up quickly, so YMMV. (Meaning if they have "repair techs" that swap boards you are probably SOL).

Personally I would replace the batteries because of age, but it does sound like your problem is probably related to inverter (since that should be the circuit that's generating your AC when operating from battery). A local electronics repair shop might even be able to help troubleshoot without a schematic because so many electronic circuits are similar to one another. I had a tech showup to repair a big screen once (cant recall the brand), but anyway he said it was the first one (of that brand) he'd had to fix, which made me wonder how he could possibly know how to troubleshoot it, but turns out TV circuit boards are more alike than different in how they function (apparently). Maybe you get lucky and UPS is the same way.
Yeah I remember the basics, I know what components are and how to read a schematic, but I also know you need to know what values to expect at certain test points to find your faults. Without that you need deep theory knowledge to feel it out and make educated guesses, and that I don't have. Again as I said, I highly doubt this has anything to do with the batteries, given the runtime I achieved a couple months ago. They don't go from "like new" to "can't even power a phone charger" in that short of a time. We don't have any "local electronics shops" round these parts, there was a TV repair guy but he went out of business a few months ago.
 

taz420nj

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Is there a way you can load test those batteries? You could take it over to Autozone etc., and see if they would hook up their load tester. OTH, you can (assuming it is two 12v batteries in series) hook up a 12v headlight (halogen type) to one battery at a time and see how long it runs and calculate run time based on amps drawn and the rated capacity of the battery... see if they match. You will know for sure if the battery is good this way.
Since I was able to cold start it off the batteries, I did that, and with just its own internal inefficiency drain, it ran for 6 1/2 hours. I don't know what the internal drain is, but I'd imagine 2 amps at 24V sounds pretty reasonable for a 92% efficient 900W UPS. So if it is, almost 7 hours on a 14Ah battery pack is spot on.
 
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myipcam

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I also know you need to know what values to expect at certain test points to find your faults. Without that you need deep theory knowledge to feel it out and make educated guesses, and that I don't have. Again as I said, I highly doubt this has anything to do with the batteries
This is the main issue. You need a service manual or calibration guide + schematic. If schematic has voltage reference points and values, great. Otherwise, you are back to hunting everywhere.

There is usually a feedback circuitry as well to ensure output is consistent. The problem could with that section as well. Again, this is all Internet troubleshooting at best..

I was suggesting battery check to eliminate the easiest portion.
 

looney2ns

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It's not been made clear, are the battery's the originals or not?
If they are original, that is a very long time for a Sealed Lead Acid battery to last. It's way past it's prime.
 

taz420nj

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No they're not. They were replaced 3 years ago. They performed just fine 2 months ago. Can we please stop harping on the batteries? Because it's not the batteries. They dont just "go bad" all of a sudden. Even if they did, it would say low battery and shut down, restarting automatically when AC is restored, not trip into overload and lock out until a hard power off. Read what I've been telling you. Please?
 

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Have you called Cyberpower? It has been a couple of years since I spoke to their tech support, but they are US based and very friendly.

Did anyone mention the batteries?
 
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Without a schematic, and like I said I’d at least try calling Cyberpower to see if you can get a tech to point you towards a common failure, you could also do it with one of the same type (that works) as a reference.

The cost might be too much, but you might be able to get one minus the batteries or something, or worst case you buy one, use it to fix this one, and then you have two working UPS!
 

bp2008

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This thread has cursed me, apparently, as one of my cyberpower UPS just failed last night with the blue display in the front dim and blinking and making sad little noises, with no power output from the back of the unit.
 

taz420nj

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Mine just beeps continuously as soon as you pull the plug, the overload indicator is on, and it reads 0V output. It does not come back on when it's plugged back in, you have to turn the switch off, wait a few seconds, then turn it back on.
 
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