Power-One solar Inverter driving me NUTS!!!

[petehall347]

from what i can make out its behaving correctly its only the "A" models that dont halt at this fault . unless yours is an "A" model

[mitsu2k]

The strange part is that the GFI LED comes on instantly before the unit has time to go through its checks. I have seen videos online where the LED did not come on until after the checks.

[CapLeaker]

You are on the wrong board.

[petehall347]

TUSB34101 USB
to Serial Port Controller

[mitsu2k]

Not sure which one is the MCU for this circuit. I do know the alarm relay is on this corner of the board. Do you think this might be the MCU? Sorry for the upside down pic. it’s the only way I can get it under my microscope.

edit: looks like that one is a USB to serial

[petehall347]

the lamp circuit will be fine i guess . what i am trying to see is what turns it on and then see what tells it to come on . there must be something that measures the resistance to earth ground from panel outputs and i suspect something there is amiss . datasheet for the mcu might help a bit .

[mitsu2k]

Yes you are probably correct. I will try and test all components in that area to the best of my ability. So far I did not see anything that was shorted. That silicone type coating all over the board makes it difficult.

[petehall347]

looks like maybe switched through negative then and using same positive as the optos .

[mitsu2k]

Wow, took me a while to sign back in also. Anyhow I traced one of the pins of the GFI LED directly to some optocouplers. Two of them. It seems like the VCC pins on each of the two optocouplers in the photo are connected directly to one of the LED pins that I traced. Not sure if this is normal or not. I have to wait for my daughter to help me because I need 4 hands to test these using two multimeters. Photo attached

[CapLeaker]

I agree... Well, now I am able to sign in with Fire Fox no problem. lol
Anyway... at this state I think it is almost impossible to figure out unless we have a working unit or schematics. Unless we get a lucky shot.

[sam_sam_sam]

It is going to take some time to get used to this new system for the BadCap forum but I do not which one is worse a website that was getting really hard get on or a new website that you have to get use to the format

[petehall347]

I can’t log in with FireFox period. It just rejects me, Used a different browser and all is good, besides I have to keep login back in once in a while, even so “remember me” is ticked off.

same here wont stay logged on . it was telling me wrong password entered for 24 hours and locked me out .
anyway the missing posts . one or 3 were mine and was looking at what actually drives the fault light on am guessing something like mcu and transistor etc . then was going to try and see what triggered the fault for the mcu to turn on the light . guessing it will be a high or low state trigger of some kind .

[CapLeaker]

I can’t log in with FireFox period. It just rejects me, Used a different browser and all is good, besides I have to keep login back in once in a while, even so “remember me” is ticked off.

[petehall347]

Hmm… are there a few posts missing? At least one of mine is.

yes posts are missing .. took me 24 hours to log back in .

[CapLeaker]

Hmm… are there a few posts missing? At least one of mine is.

[mitsu2k]

Re: Power-One solar Inverter driving me NUTS!!!

Here is what I am referring to as the computer board.

[mitsu2k]

Re: Power-One solar Inverter driving me NUTS!!!

CapLeaker, I agree. With you in that it is very strange that the LED comes on immediately before any tests are performed is strange. I saw some videos online where the red LED did not come on until after it performed. It’s RISO test. I do need to mention that there is actually a third board on the unit. I guess I assumed you guys already knew this from the pictures but that board appears to be the computer board and there is a ton of SMD components on there. I wouldn’t even know where to begin on that board, but my gut tells me that it is likely not the issue. However, anything is possible.

SAM, Thank you! You as well have been a great help. I think all of us are on the same page in feeling that it is erring out before it gets to its computer checks. I have tried my best to find bad components and clearly I am missing something or else it would be fixed by now. I will have to be more thorough. I wish I could identify those seven modules that are clamped to the heat sink. They have no markings on the top. I have lifted the clamp a little bit to look and could not see anything. If I can identify them then I could figure out how to test them.

By the way, all the black relays are new. As for carbon, yes that is suspicious as well but I could not see any small traces that might be shorted by this carbon. That’s why I was looking for other layers within the PCB. For good measure I will go back and read this entire thread again. I feel the answer may be right here and I am overlooking something. Wouldn’t be the first time. Lol

[mitsu2k]

Re: Power-One solar Inverter driving me NUTS!!!

CapLeaker, I agree. With you in that it is very strange that the LED comes on immediately before any tests are performed is strange. I saw some videos online where the red LED did not come on until after it performed. It’s RISO test. I do need to mention that there is actually a third board on the unit. I guess I assumed you guys already knew this from the pictures but that board appears to be the computer board and there is a ton of SMD components on there. I wouldn’t even know where to begin on that board, but my gut tells me that it is likely not the issue. However, anything is possible.

Thank you SAM. You as well have been a great help. I think all of us are on the same page in feeling that it is erring out before it gets to its computer checks. I have tried my best to find bad components and clearly I am missing something or else it would be fixed by now. I will have to be more thorough. I wish I could identify those seven modules that are clamped to the heat sink. They have no markings on the top. I have lifted the clamp a little bit to look and could not see anything. If I can identify them then I could figure out how to test them.

[sam_sam_sam]

Re: Power-One solar Inverter driving me NUTS!!!

CapLeaker

You might have something hear me hear me out what if you have a relay or more than one relay that has carbon tracking inside of it but it not enough to test for but enough for the micro computer to see because we do not know exactly how it doing it’s self test and where it is getting it test data from ( you might just have to replace them )

You could also have a situation where if there is an issue with the IGBT module or ic chips are having internal issues and like I said we do not have any idea what the self test is looking for unless you find a testing procedure that is this particular IGBT ic chip the only thing you can do is replace them

As far as the capacitors are concerned how to check them for leakages under load situation I am not sure exactly how you would do this without just replacing them because we do not know exactly what the self testing is looking for

*****
I once had a machine that that had an IO module fault and even technically support had not seen this issue before so they were not sure exactly what to replace except for the fact that a secondary Servo monitoring module had no interface indicator lighting up and the main Servo main switching power supply was showing all systems were functioning correctly
Well not exactly this micro controller had different levels of fault tolerance and the main Servo controller switching power supply system interface was not reporting properly the fault issues because it was that system fault and once I replaced the Servo switching power system the secondary monitoring system came back on line and finally did the complete self testing procedure and the machine came back on line *****

I posted this about the machine that I had to repair and how a self testing process can be derailed because of something else that really is not the issue and what it thinks is wrong and I have wondered if this is what might be happening here with this inverter ( the machine case issue I disabled the “ enable signal to the Servo switching power supply and forced it recognize a different set of faults because the self testing process hauled and it could not reset it properly to start from the beginning and do the self testing properly ) now how do this on this inverter I have no clue what and how to proceed with next I wish I did because I have been following this post from the beginning I wish I could tell what should be next to try

[CapLeaker]

Re: Power-One solar Inverter driving me NUTS!!!

On another thought, I recall reading in the manual about the Riso low GFI error. I read that this error of the GFI LED will come on at below 1 megaohm. This would indicate a leakage to ground on the PV side. The way, I understand this, is that the inverter is made to work on 1 megaOhm or above. When I power it on, and it does the RISO check, it comes back at 20 megaohms which is good and normal. So I guess what my point is, the 1 megaOhm that I am reading with the megger when the second board is connected may be normal.

I am not so sure about this. There is no real guideline one fits all approach. To me anything that’s 1 MOhm or below inside the inverter, is garbage in my book, but then I don’t know your inverter either.. If you look for a specific value, you find these are all over the place. But generally speaking the 1 MOhm is what most people go by unless they only deal with one unit or know it well enough to know the exact threshold, ins and outs, etc.

What really gets me is that the GFI error comes on right away, but yet no error codes. That leads me to believe it may be something the computer doesn’t monitor. Some older units have a 1A fuse installed between neutral and earth ground, but I don’t see it in your unit. Next on the list are the MOV’s and they all measureing fully open, no resistance at all. Could be leaking caps, IGBT, diodes, a bad relay, but so far nothing.
So all I can come up now with is this: these charcoal burnt spots. Is there maybe a via or trace where the black goes from the hv part of the relay to somewhere as carbon is conductive. Just very little moisture on the exposed black PCB can give you a reading on the DMM or better the Megger. Try it with 99%IPA and you will be surprised.