APC BackUPS LS-500 Schematics?

[cook]

Re: APC BackUPS LS-500 Schematics?

I know that this schematic I posted above isn't the exact match, but it should be good enough to give an idea what is going on.

For me, I'd ESR the sh*t out of them caps and replace them. I've had a run in with my small SMT a few years back, it turned itself off all the time.
https://www.badcaps.net/forum/showthread.php?t=66277

I'd change the two brown caps, the 2 black caps next to it and C51 and retest.

Got it, I will be replacing larger brown and black caps. I may do some more trouble shooting on the board first just to see if I can find other bad caps too.

[CapLeaker]

Re: APC BackUPS LS-500 Schematics?

if you see a regulator, change the caps surrounding it too.

[cook]

Re: APC BackUPS LS-500 Schematics?

if you see a regulator, change the caps surrounding it too.

I may need some help in identifying if the board has a regulator. Would that be one of the IC chips that I listed in an earlier post? Or is it something else on the board? I have pictures of the board in an earlier post.

[sam_sam_sam]

Re: APC BackUPS LS-500 Schematics?

I would definitely recommend doing the ones right next to these chip but ones you get working correctly I would highly recommend that you recap the hole board

As far as the regulator ic chip you would have to look up each part to what kind a chip it is

[cook]

Re: APC BackUPS LS-500 Schematics?

I found a regulator. It is a LM2575T. I will be tracing down the caps that are next to it.

It may be next week sometime before I have any results, but I will post what I find.

[cook]

Re: APC BackUPS LS-500 Schematics?

I finally replaced all ten of the various aluminum radial electrolytic capacitors on the board. The only ones that seemed out of spec. were the smallest ones - 22uF 16V ones, which were blue and made by JiangHai. There are 6 of these on the board. Some of them had very high ESR values. I have been running it for a few days now with the new caps and it is no longer beeping. So I am thinking that they were the cause of the intermittent beeping I experienced. Thank you to everyone who helped me with this fix.

[CapLeaker]

Re: APC BackUPS LS-500 Schematics?

good to hear that you had success!

[sam_sam_sam]

Re: APC BackUPS LS-500 Schematics?

I am glad you got it back up and running

On this voltage regulator what was on the next line was it a 5 or was it 12 this tell you what what voltage is
Now if it not have anything then it adjustable type

[cook]

Re: APC BackUPS LS-500 Schematics?

Sorry Sam_sam_sam,
I don't know what was printed on the next line on the regulator. It is all back together now, and I can't see that part. And it is not easy to get it apart.