Norsonic nor-121 - Page 1
Forum section: electronics / repair

author: Francofonico
author_rank: Contributor
timestamp: July 07, 2025, 10:57:31 am
content: Hi everybody,I haven't used my NORSONIC Nor-121 sound level meter for 6 months, and now after turning it on, it loads all the software, it tells me "starting" but immediately afterwards I get an error message: "tic_setbitmask : write err -3 (2)0".I saw that the sound level meter uses an Ibutton component model DS1994L-F5. I saw that it has its own 3Volt battery inside which should last about 10 years.the component has the internal functions of "Time Memory" and "Real-Time Clock/Calendar". so I thought that if it can no longer generate the "calendar" and the sound level meter goes to look for it because it has to insert it in the files it records, this could cause the error....I tried to buy a new one (even if Ibutton no longer produces that model) built in 2018 and therefore it should have the internal battery guaranteed until 2028. Once replaced in the sound level meter, it seems that the sound level meter doesn't see it. While with the old Ibutton after switching on, the start screen appears with a bargraph indicating the software loading level, with the new Ibutton the display remains black, sometimes the start screen appears for a second, but disappears immediately (as if it were trying to start but fails).Norsonic says they can't help me because the technicians who built this sound level meter have all retired. I am very sorry not to be able to repair it because it still works very well and I had it calibrated again a year ago.The latest message from Norsonic is this: "We have no longer parts or support for the Nor121, last unit delivered in 2011.I have asked one the R/D department, he thought there was a problem in communication between CPU and Tic.Unfortunately the original programmer of the firmware for the Nor121 has retired. There is no data to be transferred to the new DS1994LF5 (TIC, Time in can) other than the option codes.Each TIC has a unice serial number and option codes depends on this serial number, must be generated by us.The instrument should start normally without these codes, new codes must be entered in a menu in the instrument after startup".I know that there are electronics "Gurus" in the forum.... I hope someone can help me. As for diagnostic equipment I have a bit of everything from the "Textronics TDS 784D" oscilloscope to multimeters and bench power supplies as well as an LCR meter.I hope you can help me.... I thank you all in advance and look forward to your response.... Thanks again

author: beamformerXY
author_rank: Newbie
timestamp: July 28, 2025, 11:13:32 am
content: HelloI was searching for Norsonic 121 on Google when I saw your post and decided to register here specifically to respond, as I may be able to assist you since I am somewhat familiar with Norsonic devices.It is well known that Norsonic can no longer provide support. This is partly due to its age and partly because many old documents were simply deleted when the data was transferred from the server to a cloud solution, as they were no longer considered necessary due to their age. However, there are still many very old Norsonic devices in circulation, which speaks for their quality. Unfortunately, without support, one can only hope that there are no defects.I own some 121 myself and am now looking for one more again for spare parts, which is why I searched for it on Google, as mentioned.Basically, I don't see the fault here with the DS1994LF5 at first. The DS1994 has a battery, but should also work without a battery with parasitic power. This means that ROM and 64-bit ROM are always available even without a battery. Or to put it another way: if the battery is empty, the DS1994 still receives power via the 121, so that the 64-bit ROM can be read and the code/serial number (option code) can be read. Of course, since the battery is empty, the time is no longer kept. However, this should not prevent the device from starting up.Do you still have the old DS1994? If so, insert it again and check what the device does.However, when replacing the DS1994, the device should start up and you should then be able to enter a new option code using the new serial number. If you don't do this, the 121 can't communicate with the DS1994. However, I don't see any connection between the device not starting up and the DS1994. How do you want to enter the option code, when the device is not starting? Doesn't make sense.I never opened my 121 so far, but I did open its predecessor, the 110. I know that if you're not careful, you can break a lot of stuff. The devices are sturdy and durable, but the insides can be very fragile if you mess with them. The 110 had some plastic parts that connected things, which got brittle with age and broke when I took it apart and put it back together. I suppose the inside of the 121 looks probably quite the same.If it is indeed the DS1994 that is causing the error, I would guess that the error code “tic_setbitmask : write err -3 (2)0” could refer to bit 3,2 or 0 of the status register:Bit 0 would be RTF - Real-time clock alarm flagBit 1 would be ITF - Interval timer alarm flagBit 2 would be CCF - Cycle counter alarm flagBut these three bits are “read only.” However, the error says “write.” That would then refer more to the control register.There we have the following bits:Bit 0 would be WPR - Write protect real-time clock/alarms registersBit 1 would be WPI - Write protect interval timer/alarms registersBit 2 would be WPC - Write protect cycle counter/alarms registersThen my guess would be:Due to the changed serial code of the new DS1994, the control register cannot be accessed (which is powered by the battery and not by parasitic current), which sets the logic in the control register to 1, which would be permanent write protection. The “setbitmask” error would indicate that the 121 wants to write something to the DS1994 but cannot. Which is odd, because as long as the 121 doesn't know the serial number of the DS1994, it can't get past the ROM anyway and should not get the clearance to try to do anything to the control register. But that doesn't make sense either, since you couldn't enter the option code that way. So it wouldn't be possible to replace the DS1994 at all?So try reinserting the old DS1994 and see what happens.Also check inside the device to see if you can spot any defects or, as I suspect, a cable connector that is no longer properly connected.Then get back to me. I have some other ideas about what it could be. Pictures of the inside of the device could help and of the LCD Screen while starting.And: Before you dispose of the device at some point, if it cannot be repaired, please think of me. I am always looking for spare parts donors and would be willing to buy it from you.Best regards and thanks

author: Francofonico
author_rank: Contributor
timestamp: July 28, 2025, 05:31:54 pm
content: hello,thanks for replying to me. Yes, I reassembled the old DS1994. With the new DS the sound level meter does not boot the software while with the old one it loads the entire boot but gives the famous error code at the moment that the display should change to show the main screen... in the next few days I will make you a video where I will show you what happens, and I will also attach photos of the disassembled device. There are no communication cables between the three electronic boards (power supply, logic and display), they fit directly on top of each other through direct connections (like those from computers but without the flatcables... (direct male and female)... I also thought: could it be a power supply problem? Maybe a capacitor that no longer has its characteristics and therefore no longer provides the right voltage or current?I'll upload a video and some photos soon.... in the meantime,thank you very much!!!!

author: Francofonico
author_rank: Contributor
timestamp: August 01, 2025, 03:09:52 pm
content: This is the rear of the powerboard

author: Francofonico
author_rank: Contributor
timestamp: August 01, 2025, 03:11:50 pm
content: this is the front of the power board

author: Francofonico
author_rank: Contributor
timestamp: August 01, 2025, 03:13:42 pm
content: front right of the power board

author: Francofonico
author_rank: Contributor
timestamp: August 01, 2025, 03:15:08 pm
content: detail of the power board

author: Francofonico
author_rank: Contributor
timestamp: August 01, 2025, 03:20:00 pm
content: this is the logic board where you can also see the IBUTTON. In the other side of the board there is only the hard-disc

author: Francofonico
author_rank: Contributor
timestamp: August 01, 2025, 03:21:25 pm
content: this is the display board

author: Francofonico
author_rank: Contributor
timestamp: August 02, 2025, 09:20:03 am
content: this is the link to see the Nor-121 boot video with the final error message.https://drive.google.com/file/d/1dfnZLXH1n_NMPpYlSvlPNieBvgLHCpsQ/view?usp=drive_link

author: beamformerXY
author_rank: Newbie
timestamp: August 24, 2025, 07:39:36 pm
content: Hello,Sorry for the late reply. I was away on vacation and taking a digital break.Thank you for the photos. And thank you for sharing the video.It's a shame that Norsonic can no longer provide any assistance. But I'm familiar with the problem myself with other devices. They claim that they deliberately deleted old device documentation when transferring data from the old server to the cloud. Personally, I don't quite understand this, as I know many companies that still have the 121 in operation and have it serviced regularly.Nevertheless, we will try to make progress here:Regarding the video: The error occurs after the start screen. For me, this means that the usual checks (memory, internal calibration, power etc.) are successful. The error only occurs after that. However, I don't quite understand what the device is trying to write.Regarding the photos: Everything looks fine visually. The possible errors that I am familiar with from the 110, for example, are not possible here because the internal connectors have been better designed. Visually, I don't see any problems, but that doesn't mean that some component might not be defective.Back to the error code:I did some more Googling and found some tips on how to program access to the DS1994.It is quite possible that C was used as the language here or a similar one. -3 is often an error code that indicates “no access, I/O error, write error.” I would therefore interpret the error as meaning that an attempt was made to write the value to location 0 in register 2 and a -3 access error occurred.Based on the available documentation for the DS1994, I would now make the following assumption:-3 => write error(2) => register 2 => real-time clock counter0 => byte 0 cannot be writtenOr it could mean:-3 => write error(2)0 => bit 2 in the byte cannot be written, value is 0If we assume that the error is really related to the DS1994, it is strange, as mentioned, that it does not start up with the new DS1994 and lets you enter the new serial code number. That would mean that there is some other error?What you can do now:1. You can install “OneWireViewersoftware” to check the iButton:https://www.analog.com/en/resources/evaluation-hardware-and-software/1-wire-sdks/viewer.htmlhttps://www.analog.com/media/en/technical-documentation/user-guides/onewireviewer-user-guide--maxim-integrated.pdfhttps://www.analog.com/en/resources/app-notes/onewireviewer-tips-and-tricks.html2. If we assume that it is the DS1994 that is causing the error, you can try replacing the battery in the old DS1994.The problem is that you only have one attempt to do this successfully. If you make a mistake, the DS1994 will be defective.In any case, you must prevent the circuit board from being damaged. You could use other iButtons as spare parts for everything else. But the circuit board must not be damaged under any circumstances.Here are some instructions and tips:https://www.researchgate.net/publication/270579725_Replacing_the_batteries_on_ibutton_Thermochron_Hygrochron_data_loggers/downloadhttps://murdoch.is/projects/ibutton/https://www.mfelabs.com/img/ibutton-explosion.jpgKeep me posted on what happens. I'm excited to hear about it!Or you can email me directly.Greetings!

author: beamformerXY
author_rank: Newbie
timestamp: August 24, 2025, 07:46:43 pm
content: Two more:3. Since you have an oscilloscope, you could try tapping into the iButton while it is installed and reading the onwire signal. From the 0s and 1s it outputs, we could narrow down what the communication looks like bitwise and where it might be leading to an error.4. I assume you have contacted Norsonic Norway. As a tip, although it's been a few years now: Norsonic Switzerland has extremely good support and often has old manuals and service documents that Norsonic Norway no longer has. They may be able to help you. norsonic@norsonic.ch

author: Francofonico
author_rank: Contributor
timestamp: August 30, 2025, 02:59:31 pm
content: Hi beamformerXYthanks for replying... next week I'll try to write to Norsonic.ch and see what they tell me. I'll also try to analyze the Ibutton with the oscilloscope and let you know....(What should I do, do I connect the oscilloscope directly to the Ibutton terminals during power-up? Or do I take the mass on the chassis and connect the tip to the upper part of the Ibutton?) I'm waiting to cut the Ibutton because I would first like to be sure that it is the cause since Norsonic Norway told me that in their opinion, the Ibutton is only used to read the unlock codes of the options. I'll let you know as soon as I have news.... Many thanks !!!!!