On these PSU's it's usually good practice if you've had to replace the DAP053T to also replace all the optocouplers. If they aren't the issue then it's most likely something like CapLeaker mentioned. Without having one of my working (recently refurbished by me) ones in front of me or my notebook with what work I did to refurb them I couldn't give you much more details on exactly what it could be. My notes and working PSU's are on a shelf at work.
Side note about the opto's. They are a pain in the ass to remove sometimes because of the glue they use to hold them down. If you're using...
redbaron1007
Senior Member
Last Activity: Today, 05:22 PM
Joined: 06-13-2021
Location: Greenville, North Carolina
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I've had some more time using the FNIRSI component tester and I ran into my first major negative today when I was fixing an Atari 2600 with what I thought was a bulging 2200uf 16V cap. I tested it in the FNIRSI and it read at 700uf and thought ok that's to low so I grabbed a new kemet cap with the proper ratings. I decided to check it just out of habit and I got a reading of 62uf which I thought was a little weird. So I retested and got basically the same reading +- 3uf. I popped another one from my bin into the tester and got approximately the same reading again. I pulled out my old tester and...
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I got a chance to play around with it at work today and it works pretty well over all. It's accurate and unlike my other cheapo tester this one can tell identify a jfet (j111 in my case). It definitely takes longer to read things than the cheap one I pictured in my previous post though. That one is able to read in about 2 seconds for most components and maybe 5 if they are bad, but the LCR-P1 averages around 10 seconds per component and in some cases with some bad 47uf caps that were reading 2pf it took about 30 seconds.
Not sure what it tells you about the thing but if I put a bad...Leave a comment:
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What does the area look like? Could we get some pictures of where the usb port was ripped out or a before and after?
If the vias are ripped out it's possible something still isn't making a connection somewhere on the board. Usually if I have ripped vias I like to run some 34 gauge enameled wire through the via and flood it with solder to have the best chance of making the connection again.Leave a comment:
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It's technically possible the chip itself was shorted and the motherboard was detecting the short and keeping itself from turning on a potentially killing itself/catching on fire. You could try checking the IC for shorts to ground with it still on the board and then remove it and check again to see if anything changes. If there is still a short after it comes off then you'd have to either check other places on the board or inject voltage into a short to see what is getting hot on the motherboard. If you do go the route of injecting voltage though you should absolutely remove any CPU you have installed...Leave a comment:
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I saw that teardown/article in my initial looking and tried asking in a comment, but I guess WordPress never posted the comment. Plus at least in my opinion trying to figure it out like we are on here is fun/educational and generally helpful for anyone in the future looking for stuff like this or this exact thing. Educational benefits aside though would be super nice if the guy in that article reply's and is able to give me the exact value/code of the resistor.
Regardless I'm probably going to go with what CapLeaker suggested the value is based off how these types of circuits usually...Leave a comment:
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The other resistor between the gate of the mosfet and the gate of the pwm controller is a 33ohm resistor. The best I can make out on the marking to be 330, it has a small hole in it, but I'm pretty confident in that number. Looking at the blown one I'm trying to identify I'm an idiot it is connected to ground I was looking at the wrong cap when I made my original post about them being connected to the positive of the some capacitors it's connected to the negative.
So it would be safe to assume it would be a 33k resistor that has all it's markings blown off?...Leave a comment:
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I'll have to check in the morning. I've put everything away for the night. I'll report back in the morning with that info....Leave a comment:
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The more I look at the burnt resistor the more I swear it says something like 3 - 4/9, but I'm not really sure because none of the resistors on the board have 3's that are printed like that and a 9 makes more sense than a 4 given the font used on all of them. Also I've never heard of an smd resistor that ended in anything as high as a 9. Don't think this adds much to the discussion, but just seems like what I'm seeing even though I don't think it's there at all.Leave a comment:
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That's exactly the chip I was looking for. I love and hate how hard it is for me to find stuff sometimes, but other people make it so easy.
Unfortunately it is exactly what I'm looking for and not at the same time I can see it outputs to an external power mosfet that I'm assuming is the Q11 (4N65SFA1K) on my board with that resistor in between, but unless I missed it in the document it didn't have a value for that resistor. The value of that resistor is the main thing I'm looking for a the moment. If I can find the value though this datasheet is going to be extremely helpful if the...Leave a comment:
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I don't know that I follow very well, Are you saying you have a short between those two points are are they both shorted to ground?
What is the system doing when you press the power button? Do you get any beeps at all or is there nothing? Have you checked all the voltage rails for shorts and do you have the 5v/3.3v (can't remember which voltage it is off the top of my head) standby voltage on the power button?...Leave a comment:
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High Power HP1-J600GD-F12S
I got a High Power HP1-J600GD-F12S on the bench today that was killed by roaches judging by the dead roaches and large brown spots in the housing next to said roaches.
I was able to identify all the blown smd resistors on the board aside from the one located at R69. I wasn't able to figure out what any of the marking on the resistor was supposed to be and with how little of the marking was left I wasn't able to really make any guesses about what it could be from the surrounding components. It is connected to pin 1 of Q11 (4N65SFA1K) which looks like it is the gate .In the sample... -
I've got one coming in the mail on the 23rd so I can let you know when it gets here. I'm only going to be able to compare it to my cheapo component tester that cost nothing 5 years ago.
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I needed a second one and the LCR-P1 looks nicer at least. I'll report back on Monday or Tuesday when I've had a chance to try out the LCR-P1.I've got one coming in the mail on the 23rd so I can let you know when it gets...Leave a comment:
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I second this one it's worth the cost if you are programming chips more than once a year. Even then it's worth it because you'll know if it doesn't work its the code you're programming or the chip itself and not the programmer not doing its job right. Fought the cheap ones for way to long before I upgraded and it was worth it on the first chip I programmed. The software with the T48/T56 is also just so much nicer than the stuff that comes with the CH341's.
This being said I do still use a modified CH341 like the usb on in the picture with an X in the original post. I modified it to...Leave a comment:
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Yamaha HTR-3065 No power/No Standby
I got a Yamaha HTR-3065 on the bench currently that's got a no power/ no standby issue.When I plug it in it draws 0.01A from the wall, the relay for the ac transformer never clicks, there are no standby lights on the front, and pressing the power button does nothing. The fuse was not blown but upon measuring the voltages on the power low voltage power supply board (labeled operation 3 pg 89 in the schematic) they do not match what the schematic says they should be.
S9 13.7V
Pwr Ry 0V
AC Det 9.1V
Mgnd 0V GND
The two pins on the transformer for the operation... -
Update on the blown resistor. I replaced it and then a short appeared on the main DM1106EN IC. I removed the shorted cap and the short was still there. I removed the IC and the short went away. Looks like I killed the main IC unfortunately.
This DMM had a good decently long life for what I paid for it 8ish years ago ($30 on an amazon sale) so unfortunately it gets to be retired after a good working life of daily use.Leave a comment:
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That was the plan tomorrow morning just to see if I can get it to spring back to life in any way. Be very interested to see if anything is still alive, but I'll try to report back tomorrow with the results. Luckily I've got tons of surface mount resistors so sourcing it will be easy.
It was absolutely more than that thing could take and despite it having a built in bleeder resistor it most assuredly was not working. I wouldn't have thought it would blow the fuses, but both of them are definitely blown used two other meters to test them and both of them were testing open so they're...Leave a comment:
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Thank you for the photos I wasn't able to find that video when I was checking youtube for teardown videos or any repair videos for my model. That's exactly what I need. Fingers crossed that resistor is all that is wrong with it.
Whole story is simple was checking a capacitor in a microwave like I've done several times with this meter it sparked and then the meter stopped working. I was checking to make sure there wasn't any voltage left in the cap since it had been sitting around for about a week before I decided to work on it and didn't want to have a very unpleasant...Leave a comment:
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Klein MM400 resistor identification
I managed to blow the fuses in my Klein MM400 multimeter and when I replaced them I was still getting a cal and error0 message. I started looking around the board and found one resistor that was testing OL and has a visible burn mark on the top of it so I can't tell what the value is anymore. Its marked as R19 on the board and I included a picture below of what it looks like.
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The file worked great. Thank you....Leave a comment:
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