mitsu2k
Badcaps Veteran
Last Activity: 11-06-2025, 06:27 PM
Joined: 08-21-2013
Location: Bakersfield, CA
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Hi Lotas, would you trust this one from AliExpress? -
The IGBT is fried. Big hole on the underside. Problem is I cannot find a replacement unless I want to get what is likely a fake one from eBay. I have had bad luck with that in the past
Also I should mention that I ordered a new board on Aliexpress. After ordering it, The seller wanted me to upload photos of my old board for compatibility confirmation. After doing so, they said that the board I purchased will not work for me. However, they said they had a used board that would work. Well, after waiting 3 days for them to ship, They messaged me this morning saying that I need to...Last edited by mitsu2k; 07-13-2025, 12:10 PM.Leave a comment:
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I could not find anything with those specific numbers. Only the numbers on the PCB itself...
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Thank you R_J. That datasheet was helpful in getting an idea of how it works....Leave a comment:
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Lotas, I want to thank you so much for your kind help. You spent A lot of time with me and spared me a huge headache. I am going to take your suggestion and find one on Ali Express. Thank you again. You are a boss!Leave a comment:
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Lotas, I removed the current sense resistor. I had assumed it was 100% open because of how badly it was burned but apparently it was not. After removing it, I measured 280 ohms between these pins in the photo as you explained. Is this better news?
btw, the motor it drives seems ok. I have two of these mini split units so I took the board out of the good unit and put it in the unit that had this bad board, and it seems to be working normal....Last edited by mitsu2k; 07-07-2025, 07:18 PM.Leave a comment:
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I think I’m understanding now. So likely the IGBT module shorted, causing the current sense resistor to burn. Also this IGBT shorting also may have possibly caused the processor to go out....Leave a comment:
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What should I expect to see between them under normal conditions?...Last edited by mitsu2k; 07-07-2025, 06:24 PM.Leave a comment:
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Ok measured between the pins you specified on the IGBT module and there is no short. I am reading exactly 135ohms between the one leg and to each of the 3 othersLeave a comment:
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I would love to unsolder the metal film cap however the pins are directly underneath the processor chip. I would have to remove that first and it looks like it would be a nightmareLeave a comment:
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Also I noticed on the processor one of the legs must have gotten really hot. There is some solder that looks to have melted out of the through hole and onto the leg. See photos...
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Ok I checked between (+ P) and the 3 common terminals and there was no short or low resistance between them. I also did the same between the (-N) and there also was no short or low resistance.
the only short seems to be between the +P and the -N.
is this normal?
hold on. I think I did it wrong. There is a short from P to one side of the resistor pad and also a short between the N and the same resistor pad...Last edited by mitsu2k; 07-07-2025, 05:19 PM.Leave a comment:
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I cannot find any other shorts on the top side of the board. There is a large chip on the bottom side however. I have no idea what it is or how to test it. See photo....
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Thank you Lotas, I did check as you mentioned. I did not find any short circuit or low resistance across those terminals. However there are a bunch of bloated caps. I will be replacing them.
Edit: sorry, I take that back. There is a short between the “P” and “N” see last photo terminals. Any ideas?...Last edited by mitsu2k; 07-07-2025, 04:49 PM.Leave a comment:
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Yay I think I found it. Part# WSR5R0150FEALeave a comment:
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Thank you @truclacicr
I was able to find that info. Just having trouble finding the part number to order on MouserLeave a comment:
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Can someone please help me identify this resistor?
This is out of a Pridiom mini split unit. It is the power board. This component is completely charred however I was able to get a photo from a good board.
I know it is .015 ohms and 1% tolerance but that’s about it.
Thank you!!...Last edited by mitsu2k; 07-07-2025, 02:27 PM. -
Yes you are correct. It is a crapshoot. Best way is to have a working device that you can compare. Markings are often times duplicated by different manufacturers for different parts...Leave a comment:
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Ok in the example of “WI”, you are correct it is a zener but it is not 13v. I know that is what all the SMD databases say but in this case it is a 3.6v zener. I know this because I removed a few other good ones from the board and tested them....Leave a comment:
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Yes that is another good example. There are a lot of smart folks on these forums. I hope someone here can shed some light on this.
What I normally try and do is go through the SMD database and do a process of elimination using the package type of the devices and rule things either in or out. That doesn’t always work though as there can be multiple that fit the criteria....Last edited by mitsu2k; 12-29-2023, 06:55 PM.Leave a comment:
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