mitsu2k
Senior Member
Last Activity: 01-06-2024, 08:12 PM
Joined: 08-21-2013
Location: Bakersfield, CA
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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... -
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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Confused when it comes to "I" and "1" when it comes to SMD marking codes
Hello folks, I seem to have a lot of trouble when it comes to distinguishing markings on SMD components especially when it comes to the question of whether it is a 1 or an I. for example, I see components marked NI. It looks just like that. However, I cannot tell if that "I" might be a number one instead. Is there a rule of thumb that manufacturers use when using these characters? Attached is an example. This is just one example out of many I come across but it's a good illustration of my point. I appreciate any input....
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Hello redwire, yes there are transformers. The polarity of D981 and D982 seem to be opposite but both do go directly to the base of the Q981 and Q982. Would this indicate that Q982 would possibly be PNP? Please see photos.
"I think D981-K should not go to the base?" Do you mean the Cathode of D981 should not go to the base of Q981? It does.
For D982, the Anode goes to the base of Q982
btw, I found D982 to be shorted so temporarily wired this 10v zener in....Last edited by mitsu2k; 12-24-2023, 01:21 AM.Leave a comment:
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Repairing Kenwood XR900-5 car audio amp. Can't identify missing part
Hello folks, I am trying to repair this Kenwood XR900-5 power amp. Someone else had previously worked on this amp and tore off a transistor (Q982, pad and all) and I cannot identify what it was without a schematic or service manual. The one near it is an 2SCR533 NPN. I am wondering if the missing one is likely to be the same or a PNP? Can anyone make a good guess based on the photo?...
Last edited by mitsu2k; 12-23-2023, 04:03 PM. -
It just helps reduce your electric bill....Leave a comment:
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Exactly...Leave a comment:
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Sam, I am not using any batteries. The solar panels were installed when the house was built. I believe the are SunPower but I don’t know what model they are or any info on them. They are the roof tile type panels that fit in place of regular concrete roof tiles. I have wanted to go up on my roof and remove one to get the model from the sticker on the back but I am afraid of heights and being on the roof might cause me to panic and have an accident. Lol...Leave a comment:
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Inverter still working and ticking away generating power. I walk out to the garage maybe 10 times a day just to look at it and listen to that sweet ticking sound. I guess it hasn't set in yet. I still am having a hard time believing it as I have been working on this thing every day since early September.Last edited by mitsu2k; 12-08-2023, 01:14 PM.Leave a comment:
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That's what I love about you guys and this site. I have been lurking around here for years just taking information and not really giving back. Mainly because my experience level is not as great as you guys and I really didn't have much to give back. Let me tell you it feels good to give back. I have so much respect for you guys that do it on a daily basis and are so generous with your knowledge and expertise. Good job gentleman and THANK YOU!!...Leave a comment:
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CapLeaker, funny that you mention "giving up too early", the day I discovered the burned components I had been making phone calls all day trying to shop a new inverter. I had pretty much given up and was looking at a Fronius inverter for upwards of $2,000. That same evening I decided to take one more look and that is when I discovered the faulty components. After replacing the components I mounted the inverter back and wired it up. Upon turning it on, I got the same dreaded GFI light. My heart sank. I was so disappointed. So I decided to turn on the grid breaker and see if maybe...Leave a comment:
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Thank you Sam, you are correct. This all comes with experience. I certainly learned a lot from this project and I take what I learned into the next project. So it’s all good. Another great thing is this matter has been well documented in this thread so that the next guy having this issue can hopefully find this site and this thread and get a jump start on the issue....Leave a comment:
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Yes the two burned components (one diode & one mosfet) were open. The rest of the components in the other side were shorted). I suspect something shorted and went down the line and fried everything else. It ran all day yesterday with no problems and still running good now....Leave a comment:
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Here are some photos. One is before removal of the components and the other is after I removed them and cleaned up the pads....
Last edited by mitsu2k; 12-06-2023, 12:01 AM.Leave a comment:
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Yes Pete you kept asking for the model of the controller. I should have paid more attention but honestly that board intimidated me and I was too lazy to scrape off all the silicone they coated the board with. I should have listened to you earlier but I had tunnel vision and did not think the problem was on that board. Obviously I was wrong and I learned a lot from you and the other gentlemen. Next time I need to keep an open mind, get over my fear, and be more thorough with visual inspection....Leave a comment:
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They were right next to the crystals. The parts I replaced were:
3 mosfets (SOT-23) One was burned and the other two were shorted.
4 shorted diodes (One was burned) (SOD-323)
3 zener diodes (should have been SOD-323 but I used through hole wire leads instead)
I had trouble with the zener diodes trying to figure out the marking whether it was "WI" or "W1". neither of these made any sense because my research showed the WI is 12v and W1 is 2.7v but when I found some good ones on the board and tested them, they measured 3.4v and 3.7v. So I...Last edited by mitsu2k; 12-05-2023, 10:06 PM.Leave a comment:
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SUCCESS!!! Replaced those burned components and a few more that were shorted on the logic board and this is the result. I want to give a big shout out and THANK YOU to CapLeaker, SAM_SAM_SAM and Petehall347 for all your help and dedication. You guys are absolutely amazing and I could not have done this without you. THANK YOU!!...
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What is this component? Anyone know? I think it is a zener but it measures 1v. I cannot make sense whether that is a WI or W1...
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Pete, I ordered both anyway one is 50v and the other is 30v. That's the biggest diff I can see.
Mouser order placed. Will arrive Tuesday. Never been so nervous. LolLast edited by mitsu2k; 12-01-2023, 04:07 PM.Leave a comment:
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