hybridfree/eevblog-posts huggingface dataset:
Samba mount on DHO804 Rigol Oscilloscope - Page 1
Forum section: electronics / beginners

author: SC
author_rank: Newbie
timestamp: May 09, 2025, 08:19:32 am
content: Hi everyone,I'm trying to use the samba option on the DHO804 oscilloscope.I created a smb mount on linux fedora, it is accessible for "smbuser" and is workingsmbclient //192.168.1.6/private -U smbuserallow to enter the private sharing.The oscilloscope is connected with a wifi dongle (N150), so I see the Connect State: Disconnected but it is connected (I use the the RIGOL Web Control from browser).It is wrong the format I add in the setup or I cannot connect with the wifi dongle just because the oscilloscope see the connect state?Any experience on this?Thanks

author: Valzu4
author_rank: Newbie
timestamp: May 24, 2025, 10:34:54 am
content: Hi,I am having the exact same problem with my DHO924S with a wired LAN connection. In utilities menu, the network status is "connected" but when trying to connect the SMB share a "connection terminated" notification pops up. Tried every combination of slashes for the server path option (even using the SCPI commands for "/" that is not visible in the on screen keyboard), and verified that my share is accessible on Windows PC:s and Android phones. So no luck.While doing research on this issue, I found that the DHO scopes run an FTP server, that you can mount to your PC using the IP of the scope and username:"admin", password:"rigol". Even tough this is not the same as saving your data to a network disk, for me, it helps a lot that I can manage and copy the files using my computer.I'll be on a lookout if someone has had success with the SMB feature (or if this is a bug or problem with my server settings), in the meantime I hope this helps.

author: Whales
author_rank: Super Contributor
timestamp: May 24, 2025, 11:29:24 am
content: There is a good chance the scope only supports SMB2 or (more likely) SMB1. I see this lots with old photocopiers/scanners.The older versions are considered insecure and are disabled by default on your samba server. You have to edit the conf to re-enable them.

author: SC
author_rank: Newbie
timestamp: May 24, 2025, 10:11:34 pm
content: Hi,thank you for your feedback, the FTP server is working perfectly and this is helpfulStill no luck with SMB mount.

author: LiftedTrace
author_rank: Regular Contributor
timestamp: July 24, 2025, 04:34:23 pm
content: Any success with getting smb to function?Using a Synology disk station, you are able to enable old insecure SMBv1, but even with this enabled I always get Connection Terminated.Its confusing too because the default text before you enter the share says "Format:\sharename"Is this "format" the share type? smb, cifs, nfs, etc?Or is it trying to tell us the format for entering the share path is "\sharename"?Trying to enter stuff into the field, the rigol auto formatted what I typed to look like a standard path "\\server\share" so I tried the norm and I still get Connection Terminated.Is there a way to get shell access to this scope and maybe get more info on what it failing?
Same button for two circuits - Page 1
Forum section: electronics / beginners

author: hotter
author_rank: Newbie
timestamp: February 06, 2019, 07:46:28 pm
content: Hi, I have car mp3 player which I would like to integrate to my car stereo player/steering wheel buttons. So basically I want to reuse same buttons from car to switch songs on mp3 player.So my question is can I wire different circuit to a button which is used by cars circuit? It could impact another circuit correct? what are my options here if I want to use same button for 2 circuits?

author: ataradov
author_rank: Super Contributor
timestamp: February 06, 2019, 10:28:13 pm
content: That depends on how everything is connected. In general you can't just share the button.But what you can do practically depends on what the button in the car is doing and what the button in the MP3 player is doing.

author: sokoloff
author_rank: Super Contributor
timestamp: February 06, 2019, 10:43:51 pm
content: Hope that the car steering wheel button is putting the data onto a CAN bus, where you can pick it off the bus easily in digital form and do whatever you want with it.Google your car model/year, aftermarket headunit control, MCP2515, and CAN bus.

author: Psi
author_rank: Super Contributor
timestamp: February 06, 2019, 11:14:20 pm
content: Some of those steering wheel buttons are just an analog signal with different value resistors put across it depending on the button pressed.So if you can find the signal you can tap onto it and read the voltage.Aftermarket car stereos often have a wire to connect to this, then you go into the options and click "learn" so it can learn what voltage means what button.

author: MavMitchell
author_rank: Contributor
timestamp: February 07, 2019, 12:06:17 am
content: As Psi indicated, the buttons will just be different value resistors connected to ground.You would have to switch the wire from its original location to your circuit when you want to use then switch it back for its original purpose, otherwise the original functions would occur.You might be able to find a function like a long push or something that has no effect on the original that you could detect then electronically disconnect the original for a period while you control your player.
Same resistor for pull up and down ? - Page 1
Forum section: electronics / beginners

author: DJLinux
author_rank: Newbie
timestamp: April 11, 2017, 08:44:22 pm
content: specs: 5V TTL max 100 KHz. signals on breadboard.Often I saw 10K for pull up and 470 ohms for pull down.If you would have only one value of resistors which value would be a good choice for both ?Or how to calculate pull up and down for 5V TTL stuff ?Does the frequency of the signals are a part of the calculation ?thank youDJ

author: cowana
author_rank: Frequent Contributor
timestamp: April 11, 2017, 08:56:20 pm
content: 10k is standard for a pullup or pulldown.470\$\Omega\$ sounds unusually low - are you sure that wasn't driving an LED in series to ground?

author: edavid
author_rank: Super Contributor
timestamp: April 11, 2017, 09:26:03 pm
content: It depends on exactly what you mean by TTL.A standard TTL gate input, like on a 7400, has an 0.8V maximum input low level, and sources 1.6mA of current. So, the highest value pulldown you would want to use is 0.8/0.0016 = 500ohm.If it's a different TTL family, or an oddball part, check the datasheet and recalculate.P.S. This is why you try to avoid using pulldown resistors with TTL.

author: DJLinux
author_rank: Newbie
timestamp: April 12, 2017, 04:02:06 am
content: Quote from: cowana on April 11, 2017, 08:56:20 pmYou are right my fault :-)Quote from: edavid on April 11, 2017, 09:26:03 pmpulldown = U / Iand how to calculate pullup for example if high pegel of the IC starts at 2.8 V - 5.0V ?is it = 2.8V / I (max or min current from datatsheet of the part)Sorry for this stupid questions but it's a beginner forum section :-)DJ

author: edavid
author_rank: Super Contributor
timestamp: April 12, 2017, 04:18:22 am
content: Quote from: DJLinux on April 12, 2017, 04:02:06 amThe highest value pullup is: (minimum VCC- minimum VIH) / maximum IIHSo for a standard TTL gate input: (4.5V - 2.0V)/40uA = 62KI hope you were asking about input pullups rather than output pullups, because that's the question I answered

author: Zero999
author_rank: Super Contributor
timestamp: April 12, 2017, 07:41:45 am
content: Quote from: DJLinux on April 12, 2017, 04:02:06 amWhat's the part number of the IC?Can you post a link to the data sheet?If the part number is something like DM74xx or 74LSxx which are TTL then the answers are given above. If it's 74HCxx, 74HCTxx, or 74ACxx etc. then a much higher value can be used, limited by noise pick-up and the required speed.
Sampled signal spectrum ? - Page 1
Forum section: electronics / beginners

author: harrysmith
author_rank: Contributor
timestamp: January 06, 2021, 08:37:14 pm
content: Hi guys, someone knows the matlab program to plot a the spectrum of a sampled signal ; example : signal x(t) ? thanks

author: tggzzz
author_rank: Super Contributor
timestamp: January 06, 2021, 09:58:24 pm
content: The answer is in your other thread.
Samples in Europe? - Page 1
Forum section: electronics / beginners

author: anfang
author_rank: Regular Contributor
timestamp: August 24, 2016, 04:20:36 pm
content: Has anybody in Europe ordered samples from companies as a private person/Uni student and actually got them?I have read stories about TI samples being sent from the US to the EU and incurring in shipping and customs charges in the order of hundreds of euros.Do you have any successful experience with receiving samples in the EU? With which companies?

author: Jeroen3
author_rank: Super Contributor
timestamp: August 24, 2016, 04:36:12 pm
content: Samples from TI, Linear, AD and ST were no problem using my university mail.They ship express, no cost for you. Unless customs think otherwise, but they use courier like ups/dhl. They handle this internally.

author: pyroesp
author_rank: Regular Contributor
timestamp: August 24, 2016, 04:45:08 pm
content: I used to order samples from Microchip and never had trouble.I used my university e-mail, or my website's e-mail.

author: chris_leyson
author_rank: Super Contributor
timestamp: August 24, 2016, 04:52:22 pm
content: I've had connector samples from Harwin, Samtec and Binder but only if they were on long lead times or not stocked.

author: Srbel
author_rank: Frequent Contributor
timestamp: August 25, 2016, 10:04:43 am
content: I had received a couple of voltage regulators samples from Linear Technology, a few years ago. I registered with my private e-mail address. I was a student then, but did not have a student e-mail. The postman had just handed them to me, without any payments. It was written on the envelope that postage was payed.

author: Molenaar
author_rank: Regular Contributor
timestamp: August 25, 2016, 12:16:22 pm
content: No problems here with samples from ST, TI and AMS.

author: anfang
author_rank: Regular Contributor
timestamp: August 28, 2016, 09:53:38 pm
content: Thank you everybody for your answers.A last question: do manufacturers ship samples in boxes or in envelopes?

author: JPortici
author_rank: Super Contributor
timestamp: August 28, 2016, 10:54:29 pm
content: Quote from: anfang on August 24, 2016, 04:20:36 pmyep. many times. with microchip and ST though.i had an account with analog and TI too with institutional email but i never ordered from them

author: Srbel
author_rank: Frequent Contributor
timestamp: August 29, 2016, 10:22:07 am
content: Quote from: anfang on August 28, 2016, 09:53:38 pmMy 2 chips from Linear came in an envelope.

author: 128er
author_rank: Regular Contributor
timestamp: August 29, 2016, 07:45:53 pm
content: Ordered five pieces of the MC33880 from NXP a few month ago. They are 3-4€ each in low quantity at Mouser. Shipped with UPS, no costs for me. Had no problems. Very nice from NXP, thank youWill buy a few more of them, cause they worked very well for me.
Samplig rate and SNR - Page 1
Forum section: electronics / beginners

author: rakeshm55
author_rank: Regular Contributor
timestamp: November 09, 2015, 11:17:24 am
content: Hi,Recently i came across""Oscilloscope signal-to-noise ratio can best be improved by: Increasing the oscilloscope's sample rate ""in Friday Quiz published in eetimes....link as given belowhttp://www.eetimes.com/author.asp?doc_id=1328192&page_number=5How can sampling rate affect signal to noise ratio??"Can some one help me understand the concept.......My understanding is limited to SNR affected by adc resolution.....

author: rs20
author_rank: Super Contributor
timestamp: November 09, 2015, 11:38:32 am
content: My guess is that they're referring to Hi-res sampling mode; where consecutive samples are averaged together to achieve noise reduction (see here). In principle, with a higher sampling rate, hi-res mode can do more averaging and thus reduce noise.

author: scatha
author_rank: Regular Contributor
timestamp: November 09, 2015, 12:00:25 pm
content: Oversampling then filtering reduces quantization noise, which could be what they are referring to.
Sampling PWM, how to estimate resulting waveform - Page 1
Forum section: electronics / beginners

author: NightMoth
author_rank: Contributor
timestamp: July 23, 2025, 01:58:59 pm
content: Hello allI have attached picture to illustrate my questionAs I understand question I'm asking for belongs to the field of sygnal analysis.Lets say I have pwm signal with period T = 100uS, t_high = 48uS, t_low = 52uS.And Im sampling this pwm signal with sampling period of 107uS.I want to derive what resulting sample waveform will looks like (I can see from sketch that new waveform will have much longer period).I'm interested in general formula/method.Can anybody tell me name of related formula or method or provide link were to read about it?I don't know how to google this question. When I'm googling "sampling of pwm formula" or "samplig of square wave fromula" all results i'm getting is about Fourier spectrum of square waves, but not the formula I'm looking for.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 27, 2025, 07:19:03 pm
content: https://en.wikipedia.org/wiki/Nyquist_frequencyhttps://en.wikipedia.org/wiki/Undersampling

author: Benta
author_rank: Super Contributor
timestamp: July 27, 2025, 07:22:22 pm
content: Andhttps://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem

author: radiolistener
author_rank: Super Contributor
timestamp: July 27, 2025, 08:56:35 pm
content: What you're looking for is the theory of discrete-time signals, which is a branch of signal theory that specifically deals with signals defined only at discrete points in time, as in the picture you provided.Unlike continuous-time signals, which are defined for every instant in time, discrete-time signals are sequences of values sampled at specific intervals. When you sample a periodic signal, like your PWM waveform, with a sampling period that is not an integer multiple of the signal's period, the resulting sampled signal exhibits aliasing and phase accumulation effects. These effects can lead to visually longer or distorted waveforms, usually described by beat frequencies or stroboscopic effects.To understand this behavior rigorously, I recommend studying the theory of discrete-time signals and systems, which provides the mathematical foundation for how sampling affects signal shape, periodicity, and perceived frequency.

author: MariuszD
author_rank: Regular Contributor
timestamp: July 28, 2025, 07:37:12 am
content: Quote from: NightMoth on July 23, 2025, 01:58:59 pmOnce, sampling oscilloscopes based on this principle were popular. In older digital oscilloscopes, there is a function for equivalent time sampling.Instead of sampling every 7us, you sample every n*T+7us.where n is an integer and T is the period of the sampled waveformFor it to work correctly, the frequency of the waveform being tested must be stable. With an RC generator powered by a noisy source, it will have high jitter and this method will work poorly.Search for "equivalent time sampling"
Sampling VGA signals - Page 1
Forum section: electronics / beginners

author: oryagev
author_rank: Newbie
timestamp: January 05, 2014, 08:46:08 pm
content: Hi,I have an old product with a unique VGA output connector, and i have lost its cable.I wonder what's the best way for me to reverse engineer the connector's pinout, so that i could make a new cable myself.Thanks,Or

author: Unknown
author_rank: Unknown
timestamp: January 05, 2014, 08:52:37 pm
content: Quote from: oryagev on January 05, 2014, 08:46:08 pmMentioning the device in question may yield some useful results for you, unless it's a secret? I'd probably start off tracing the pins in the device, may all become clear quite easily, certainly easier than random guessing on the pins.

author: sachleen
author_rank: Contributor
timestamp: January 05, 2014, 08:52:58 pm
content: Are there any markings on the connector that you can look up online to find a datasheet? Or maybe the driver chip?

author: andtfoot
author_rank: Unknown
timestamp: January 05, 2014, 10:39:36 pm
content: Not much info to work on, so this is a bit rambling...There's a good chance that the chassis or shell of the connector will be common with the ground pins. So you could start by checking for continuity between the shell and each of the pins.If you find the ground pins, then you can check for resistance between them and any other pins.If you have a scope, then you can try and see what is coming out of each pin that has some sort of connection through to ground. Square wave looking stuff would probably be DDC lines (I2C), regular pulses with big gaps may be sync lines, misc noise in-between dead spots might be the colour (+ sync maybe?) lines.You may have to put 75R resistors between the colour/sync lines and ground to get the device to output anything.Beyond that, more info is needed. Is it full VGA connection like on a computer (with DDC, +5V/detect, etc), RGBHV, RGBS, RGB, etc....?
Samsung fridge ice maker repair tray rotating issue - Page 1
Forum section: electronics / beginners

author: ChrisRich
author_rank: Newbie
timestamp: December 16, 2024, 01:50:08 pm
content: Hi, new to the forum but hoping you can help with a repair I am doing. The circuit board comes from the ice making machine in a Samsung fridge. There is a small motor that rotates the ice cube tray once they have been created so that they fall out, then rotates it back so it can be refilled with water. Problem is that the tray is rotating to drop the cubes, but then keeps going (eventually hitting the frame and jamming) and fails to rotate back.The board seems quite straightforward. There are 2 components on the board. The first is a switch (push to make, release to break). This is a test button, push it and it triggers the tray rotation.The second is a sensor of some description and it is the component that I think has failed. Looking at the plastic mechanism, there appears to be a small magnet on a plastic arm. That arm runs along a cam on the main shaft of the tray. When rotation is triggered the magnet is moved away from the sensor and the shaft rotates. The shaft continues to turn until the the arm passes the cam, then it moves back, bringing it back next to the sensor. The sensor has three legs. I’m guessing that when the magnet moves away from the sensor it switches one circuit to trigger the start of the rotation. Then when it comes back near it again it switches the other way triggering the counter rotation. I have added a few images.I tried using my meter set on 2k ohms to test any continuity between the 3 legs and there was none. I then tried again with the magnet present, but no change.Can anyone tell me if my thinking is accurate, how I could test the sensor to see if it’s working properly.I think it is a Hall effect sensor.Code on top line is difficult to see but looks like W50BBottom line is readable 12U3If anyone can tell me how I could test it or get an equivalent replacement that would be fantastic.

author: fzabkar
author_rank: Super Contributor
timestamp: December 16, 2024, 04:19:24 pm
content: EW-750B, Asahi Kasei Microdevices, Unipolar Hall Effect Switch, 3～26.4Ｖ, SIP:https://www.mouser.com/datasheet/2/1431/ew750b_en_datasheet-3010126.pdfhttps://es.aliexpress.com/w/wholesale-W50B-hall.html(photos)The output of the sensor should change state when the magnet moves past.

author: floobydust
author_rank: Super Contributor
timestamp: December 16, 2024, 06:02:39 pm
content: Welcome to the forumsLast time I fixed a Samsung icemaker, lying on my back my head in the freezer it felt a little chilly. Then I understood the recall and class action lawsuit. Some models have issues.You could power it up on the bench using a 9V battery and LED+resistor if you want to test it there. It's three wires to clip to.It looks like BLK is ground, YEL +DC power, BLUE is output (open-collector). I would double check in case I've got it wrong.Mouser has them as 412-EW750BYou can substitute the Hall Effect sensor if that part is too hard to find, but it's not easy matching the magnet strength.
samsung galaxy s4 active. - Page 1
Forum section: electronics / beginners

author: Aigars
author_rank: Regular Contributor
timestamp: April 26, 2014, 01:00:04 pm
content: hi gys. a have prooblem wif may phone. i get dowloaded update and after updates, may phone all time going to the restart. coming up logo and restart. like this all time. when i tray gou in wol up, power, home buton. its starting up, shoving recovery mode and agen gou restart. maby samone can help.

author: miguelvp
author_rank: Super Contributor
timestamp: April 27, 2014, 01:33:25 am
content: try any of the thousand android forums out there.http://androidforums.com/samsung-galaxy-s4/http://forums.androidcentral.com/samsung-galaxy-s4/http://www.droidforums.net/forum/samsung-galaxy-s4/Or:http://forum.xda-developers.com/galaxy-s4But on xda, search for the problem first, they don't like people that ask something that's already well known by doing a search.

author: IonizedGears
author_rank: Regular Contributor
timestamp: April 29, 2014, 09:48:01 am
content: Watch out though, people can get mad if the asker isn't the best at the forums native language as the asker can't convey their questions properly. I understood your post but I can definitely see room for a misinterpretation.~Ionized Gears

author: Narmaraktuk
author_rank: Contributor
timestamp: April 29, 2014, 10:24:03 am
content: Your battery may be on the way out. There is a known problem with galaxy s4 batteries of a certain manufacture date. If your battery shows any signs of bloating, contact Samsung for a replacement battery.
Samsung Galaxy S7 screen replacement project - Page 1
Forum section: electronics / beginners

author: bosikrisz
author_rank: Newbie
timestamp: June 20, 2019, 01:13:12 pm
content: Dear Forum members,At first, let me thank you that i can share my story with you. I hope you can help me with my little project.(I am Chris, a student from Hungary. My English needs a bit improvement so please sorry me for grammatical mistakes. I study Mechanical Engineering so I am not really in electronics. I know soldering, the basics usage of a multimeter and I have knowledge about basic electronic components. I work as an intern at a company with electronic manufacturing so if I need special soldering, X-raying any parts or any special tools I have a good place to look for help)Let me start at the beginning of the story. It all started 1 year ago, when I unfortunatelly broke my Galaxy S7's screen and it turned out that the touch screen broke as well (not only the glass on it). I decided to buy another phone and if I have the mood to replace the display, I will buy a new one and replace it. I put the broken display to the trash and the phone to the "waiting for time and energy" drawer. It has stayed there in the last few months, since the time I successfully bought my first car. The car had a basic radio in it, so I changed it to an amplifier and added a really old tablet as a dashboard screen with a nice 3D-printed frame around it. The problem with this tablet is, that it has no bluetooth connection in it and it is really really slow. I can hardly change between applications without frozing. I do not want to spend money on buying another tablet only to put into the car.I researched a lot about homemade media centers in cars and i had a "vision" one day that I have a working phone in my drawer which has strong hardwares and software in it and it needs "only" a screen with 7" size.I know that I should study more about LCDs and AMOLED screens and how they work and I could answer the question myself (and if there is a way to go on with the project, i will) but first I wanted to ask some professional guys who can make my research easier(before wasting hours on it):Is there way, to design (or order) a touch screen display (does not really matter what type) with 7" size which I could connect to my galaxy S7 motherboard and use it as a media center in my car?What have I checked?-Manufacturer's screen type: Super AMOLED capacitive touchscreen, 16M colors-Original size: 5.1"-Original resolution: 1440 x 2560 pixels-The display is connected to the phone with an FPC connector (attached a picture of it--> that's just a test cable with the connectors on it want ot show you to check displays before assemblying the phone)-on Ebay I could find special PCBs which I could use as an adapter if it's needed (from FPC to DIP) .That's all I know about this topic. If there is way to do it, what else should I check and what other components would I need to buy to finish it with success?Thank you guys for the help and I hope you can help me with the problem.Regards,Krisztián
Samsung Odyssey G9 (c49g95tssr) no picture or backlight. Power LED shows - Page 1
Forum section: electronics / beginners

author: grimreaper
author_rank: Newbie
timestamp: September 03, 2024, 09:49:57 am
content: hey guys,i bought 2 samsung odyssey g9's for a decent price. they both have the exact same fault. when plugged into a power source, the blue led powerlight shows, but when turned on there is no picture, no backlight, no menu, nothing. when plugged into a laptop the laptop recognises the monitor, but keeps disconnecting and reconnecting.The power supply connects to the main board. There is like a checkpoint on the mainboard that says 20v, and i tested that with a multimeter and i can confirm that I'm getting 20v in. There are a few ribbon cables coming off from the mainboard to the T-CON. I tested those voltages, and those are really low. Less than 1v.I attached a picture of the main board.1 - 20v power cable directly from PSU2 - ribbon cable going to TCON - LOOKS LIKE CORRECT VOLTAGE IS OUTPUT3 - another ribbon cable going to TCON - DOESNT LOOK LIKE CORRECT VOLTAGE IS OUTPUT (<1V)4 - cable leading to power button and LED backlight (BACKLIGHT DOES NOT WORK, BUT POWER LED DOES) (DOESNT LOOK LIKE CORRET VOLTAGE IS OUTPUT (<1V))5 & 6 - labelled LED, not exactly sure where this goesdont have any schematics or diagrams unfortunately. any ideas?thanks

author: indeterminate
author_rank: Regular Contributor
timestamp: September 03, 2024, 11:04:07 am
content: Start with the power supplyit sounds like the standby supply is working but the main power supply is not starting up.be careful there will be 400v on the board for a long time after it is disconnected from mains.

author: grimreaper
author_rank: Newbie
timestamp: September 03, 2024, 02:28:21 pm
content: The power supply connects to the main board. There is like a checkpoint on the mainboard that says 20v, and i tested that with a multimeter and i can confirm that I'm getting 20v in. There are a few ribbon cables coming off from the mainboard to the T-CON. I tested those voltages, and those are really low. Less than 1v.I attached a photo and a bit more information in my original post. from my beginner knowledge of electronics () after testing the power supply, i think its fine.

author: jzx
author_rank: Regular Contributor
timestamp: September 03, 2024, 06:44:22 pm
content: Check if you have 20 Vwhen the monitor tries to start (connected to a pc). Sometimes the power supply can give the voltage unloaded, but not loaded, then the main circuit goes off again and the cycle repeats. The power suply cannot give enough current, often due to bad electrolytic capacitors.

author: Rookie_Worker
author_rank: Newbie
timestamp: April 28, 2025, 12:36:26 am
content: I am having the same exact problem with the same exact monitor. Any chance you ever figured out what was going on or any ideas?
SamSung Odyssey G9 Black Screen - Page 1
Forum section: electronics / beginners

author: Rookie_Worker
author_rank: Newbie
timestamp: April 27, 2025, 11:36:13 pm
content: Hey everyone, I am definitely a rookie in this field, but I can usually learn just about anything with a little guidance. With that being said I have a 2022 Samsung Odyssey G9 49inch Model:C49G95TSSNTHE PROBLEM: I have a black screen. No backlight on the screen. Complete black. Except for the little blue light that flashes every about 10 seconds on the power button.INFORMATION: I can connect to a PC by HDMI and i can duplicate the screen but no picture on the G9 still just black. It also disconnects and reconnects every 10 seconds. I tested the power coming into the motherboard and TCON. getting over 19V on both except for when it resets it will drop to about 13V and then restore to 19v. This will happen whether it is connected to a PC or disconnected. I am leaning towards the PSU either being stuck in standby mode or just the PSU being bad. Like I said this is not my field of expertise whatsoever. So, this is where I get lost. Could it possibly be something like a bad driver or software causing the black screen or possibly that my screen just died randomly with no warning scenes. I can find another one of these on marketplace for probably $300 which is a lot of money for me right now. Which makes it hard to justify fixing this thing. Unless I can diagnose enough to be a little more sure buying a PSU has a good chance of paying off and working.Thanks for any help and if you need any more information just let me know. I am new to this so I wasn't sure how detailed i needed to get with the information.UPDATE: (I just realized this would probably be better in the repair section. If someone thinks it would be better to have there and tells me how to move it. I'll move it over there. I Don't want to make a second post there. I know most forums don't like that.)

author: indeterminate
author_rank: Regular Contributor
timestamp: April 27, 2025, 11:59:38 pm
content: Shine a torch into the screen when there should be an image there and have a look to se if you can see an image.if you can see a faint image then it is a back light failurechances are that it is a single LED that has failedits a cheep fix just mechanically complicated to do on most screens.

author: Rookie_Worker
author_rank: Newbie
timestamp: April 28, 2025, 12:13:51 am
content: @indeterminate Hey are you the one that bought two of these screens and had the same problem. I actually joined this forum because of that post. because this is the only place i could find giving out actually information on how to fix it and not just unplug it and plug it back in. But yeah, I'll give that a try and even with the power drops you think that could be the case?

author: Rookie_Worker
author_rank: Newbie
timestamp: April 28, 2025, 12:23:50 am
content: Quote from: indeterminate on April 27, 2025, 11:59:38 pmI didn't see anything with the torch, but it was a good idea? Any more ideas?
Samsung Plasma PN64H5000 blowing fuses - Page 1
Forum section: electronics / beginners

author: CEV
author_rank: Newbie
timestamp: July 26, 2019, 09:54:16 pm
content: My Samsung Plasma PN64H5000 blew a fuse. The one right next to where the power cable plugs into. I originally thought the BN44-00690A Power Supply Board was bad, so searched where I could buy a new one. ShopJimmy show they sell them for $85, but do not have any in stock. Couldn't find anywhere else either.So did some research and found out how to test a ceramic fuse. I know seems pretty simple, but I did not know. Tested bad, so ordered some. Finally got it desoldered and a new one put in, and that one blew as well.I am now at a loss. I do have a multimeter, but had to watch a Youtube video on how to use it to test a fuse. Looking for suggestions on what to do next. I did find a couple of places online where you can ship them your power supply board, they will fix it for about $65, and then ship it back to you. But not sure if any of these places are trustworthy. If someone has a suggestion on what I could try next, or even know of a reputable place to send the board for repair at a decent price, I would appreciate it. That's assuming it's the powerboard that is bad, if I am correct.Thanks,Chad
samsung smart/fast charger - Page 1
Forum section: electronics / beginners

author: M6YRU
author_rank: Contributor
timestamp: November 03, 2018, 07:27:33 am
content: Hi de hi happy campersjust got a galaxy s7 and found out you can have a fast charger that uses 9vnow i have searched google and youtube for fast charger etc etc and got loads of useless videos of how these chargers work sooo, if someone can enlighten me how they work please...are they a 9v psu and the phone is happy with it but a none supported phone will fry?are these chargers output normally 5v with a communication line to make the dc-dc converter push more voltage so any other 5v device will be safe unless it communicates?inevitably my idea is if i can is make one into my battery bank box for high speed charging, currently im using a 4s10p 18650's going to a 5a buck converter which sits at 5.2v feeding usb sockets and the center data pins are shorted for 1amp charging on normal phonesmany thanks for your ideas and help

author: kjr18
author_rank: Regular Contributor
timestamp: November 03, 2018, 09:51:39 am
content: Almost all of chargers use data lines to regulate charge current. Simple chargers use voltage dividers or shorted data lines to tell phone how much current they can deliver. Quick charge phones use similar method, with one exception: voltage on data lines is set not by a charger (voltage dividers) but by phone. That way if you connect a normal phone to a quick charge charger nothing bad will happen, because phone will not request higher voltage. Some quick charge technologies even use data lines for more complex communication with a charger.You can read more on this subject on this site.

author: firehopper
author_rank: Frequent Contributor
timestamp: November 03, 2018, 01:42:27 pm
content: you want to look for a QC2.0 or 3.0 charger, that is what the samsung phones are compatable with for quickcharge the phone tells the charger what it wants. and the charger responds.
Sanity check - is there something wrong with this RS232 receiver design - Page 1
Forum section: electronics / beginners

author: daqq
author_rank: Super Contributor
timestamp: January 08, 2014, 08:44:15 am
content: Hi guys,There's a device/system that is just a passive receiver for RS232 signals coming out of a remote device (1 to 10 meter cable, baud rate 9600). The schematic for the Rx part is in the attachment.Apparently, there is the occasional problem with these devices that they go dead for reasons unknown. The rest of the system works well. Is there any way this input setup could kill the system or allow a spike from something to kill the rest of the system or the Rx part?Edit: The zener is actually a 3.9V, LTSpice does not have its model.Thanks,David

author: SeanB
author_rank: Super Contributor
timestamp: January 08, 2014, 09:40:35 am
content: I would suggest another 10k resistor between the zener anode and the base of the transistor, so that you get more overload protection, as in the current diagram the zener is not really doing anything but acting as a diode. Most likely the transistor fails from reverse base current if the zener goes open circuit. You could replace the zener with a regular diode as well, will make no difference but the capacitance will be lower.
sanity check on cascaded gain amplifier (temp co gain error) - Page 1
Forum section: electronics / beginners

author: SArepairman
author_rank: Frequent Contributor
timestamp: April 26, 2014, 04:50:34 pm
content: Before I buy some parts I want to check something with you guysif I had a two gain stages in a row. each gain stage has a gain of 10.000004 (assuming 1k/10k with 0.2ppm drift, drift in opposite directions over 1C)so the total error is 10.000004*10.000004=100.00008error is 0.0000799% / degree celciusif i instead had a single stage, with 0.2 ppm resistors, of 1000 and 100000 ohm1000*(0.2/10^6) = 0.0002 = 999.9998 ohm100000*(0.2/10^6) = 0.02 = 100000.02 ohmgain = 100.00004, gain error = 0.000039%so, if i split my gain over 2 stages rather then 1 stage my temperature coefficient error doubles?these prices got me so anxious i need my hand held lol* I don't care about offset error, only gain error

author: IonizedGears
author_rank: Regular Contributor
timestamp: April 29, 2014, 10:03:18 am
content: Well, yeah, you now have double the temp sensitive parts so there is twice as much deviance. Also, make sure that one stage could go that fast to give to a gain of 100 rather than two with each a gain of 10. Essentially by using one stage rather than two gives the one stage 10 times the work.~Ionized Gears
Sanity check on mini molex connector data sheet - Page 1
Forum section: electronics / beginners

author: Ammar
author_rank: Regular Contributor
timestamp: November 19, 2018, 11:43:03 pm
content: I am using the molex connectors in the attached data sheet. I have FPC feeding into them and I need to know whether the copper is on the top or bottom on the FPC. I hope the diagram is clear. Is it option A or option B?
Sanity check on panel mount deutsch style connectors - Page 1
Forum section: electronics / beginners

author: ColoradoEngineer
author_rank: Newbie
timestamp: September 29, 2023, 10:09:45 pm
content: Hi,I have started using deutsch style connectors (specifically Amphenol's AT version) for a DIY project. The connectors are working great for my project, however I am looking for a panel mount version of the connectors. After a lot of googling, the only panel mount version I have been able to find is a receptacle which has exposed pins. In my application, the panel mount would be the hot side, with the exposed pins I wouldn't think this would be appropriate to use.Wanted to see if I was missing something or if these connectors are just not used for this application. Are another style of connectors used for panel mounts?Thanks!

author: m k
author_rank: Super Contributor
timestamp: October 09, 2023, 03:04:18 pm
content: Card edge used be a standard once.The problem with pins is that the orientation must be accurate or thickness high.Eurocard has quite thin pins but slide-in distance is also quite long.

author: Terry Bites
author_rank: Super Contributor
timestamp: October 09, 2023, 03:51:17 pm
content: PanelMate AT?
Santity check units. Is 10uW a plausible drive-level for mcu crystal? - Page 1
Forum section: electronics / beginners

author: julian1
author_rank: Frequent Contributor
timestamp: January 16, 2021, 11:27:44 pm
content: I have a stm32 board, using a HC49 crystal for HSE. I want to confirm the drive level does not exceed the crystal manufacturer's power limit (0.5mW).Following the approach in 4.4.2, p13.http://www.emcu.it/DOC-Digitale-Generale/AN2867%20Oscillator%20design%20guide%20for%20ST%20microcontrollers%20rev5.2.pdfWith,F=8MHz xtal datasheet.ESR=60ohm xtal datasheet.CL1=CL2=15pFCs=8.5pF (implied from CL1=CL2=15pF)Cprobe=9.5pF "A typical 10Mohm probe is 9.5 pF"Vpp=0.8V measured with scope at drive pin of crystal.I calculate,> var square = x => x * x;> 60 * square(3.14 * (8*1e+6) * ((15 + (8.5 / 2) + 9.5)* 1e-12)) * square(0.8 ) / 20.000010014198528== 10uW.The crystal is rated at 0.5mW, which is a big margin (50x). As long as I haven't made any mistakes with formula, values or units.My gut says this detailed calculation is overcomplicated and unnecessary, and if common parts are used, and it starts oscillating then it's probably good enough.On the other-hand most schematics show an optional current-limit resistor to reduce power.Does 10uW sound reasonable for a mcu crystal drive-level with typical ESR and cap and Vpp values?Is there a better (simpler) approach?- other than taking measurements with a current-probe which I don't have.

author: Manul
author_rank: Super Contributor
timestamp: January 17, 2021, 11:23:01 am
content: In practice, measuring crystal voltages will result in somewhat unreliable results. It is easier if oscillator has one crystal pin grounded, for eg. colpitts. But normally current probe should be used. You may try to DIY and calibrate by using signal generator at the frequency of interest.10uW seems ok to me. Practically speaking, if you are worried about startup reliability, you may try adding extra ESR to the crystal (series resistor), to find out at what point it stops working. Then you may estimate how far from "not starting" the circuit is. It should not be "on the edge of working", because part variations would make your design unreliable.
Sanwa YX360TRF analogue  multimeter  / Canadian or U.S. Dealer??? - Page 1
Forum section: electronics / beginners

author: whitte
author_rank: Contributor
timestamp: January 30, 2011, 06:32:44 pm
content: This popular inexpensive analogue meter commonly used in other parts of the world does not seem to have any dealers in Canada or the U.S.....only Asia......Anyone aware of a domestic retailer for this meter ?Or perhaps a comparable one ?W.W.

author: vr2whf
author_rank: Contributor
timestamp: February 03, 2011, 04:35:00 pm
content: Sanwa is quite a popular analogus multimeter here in Asia. I once met a sales lady at the Sanwa's booth during the half yearly electronics show in Hong Kong, giving me some gift but unforunately no multimeter for free.According to the Sanwa website, the only "official" distributor for N.A. is in Canada.http://www.bhumika.ca/and, I spot a few seller from Hong Kong and Taiwan are shipping 360TRF worldwide. I notice the price is almost double than the street price in Hong Kong.http://cgi.ebay.com/SANWA-Linear-Multitester-YX-360TRF-Multimeters-Japan-/140315578793?pt=LH_DefaultDomain_0&hash=item20ab75d1a9http://cgi.ebay.com/SANWA-Analog-Multitester-YX-360TRF-Multimeters-Japan-/120675732895?pt=LH_DefaultDomain_0&hash=item1c18d58d9f

author: grenert
author_rank: Frequent Contributor
timestamp: February 04, 2011, 04:47:11 pm
content: Is "Made in Japan" for real? All of the sales from China lead me to believe otherwise...

author: saturation
author_rank: Super Contributor
timestamp: February 04, 2011, 06:29:42 pm
content: You have to be very careful about buying Sanwa brands in Asia, many counterfeits are there; still the case when I was there 3 months ago. Best bet is always through an authorized Sanwa dealer, its about $25 anyway only, in local currency.

author: stan001
author_rank: Contributor
timestamp: February 16, 2011, 07:43:49 am
content: Read the brand carefully.. there is a popular clone called Sunwa from China with similar font, colour and model names too.. cheapest ones cost less than USD10.00Interestingly, I find most of local electronic stores in Malaysia seems to use the Sunwa analog meter brand for their own use... even one of the testing electronic component site even recommended it for testing electronic components for repair technicians because it have x10k ohm range that can output 12V.They are good for testing components but I wouldn't rely on them for accuracy measurements or using quality parts inside.

author: Unknown
author_rank: Unknown
timestamp: February 16, 2011, 10:40:30 am
content: Quote from: stan001 on February 16, 2011, 07:43:49 amWhich is nice for working with modern components which are often designed for 5V or less.
Sapphire GPRO X080 (RX 6700) I attempting to add video output - Page 1
Forum section: electronics / beginners

author: Rabit0
author_rank: Newbie
timestamp: March 31, 2023, 01:12:36 pm
content: I think add top 2 display ports due schematic that I have from Rx 5700 full info and RX 6700 only info about resistors and capacitors, but they they have different values for capacitors on bottom display port and one of smd needed for HDMI is no longer available to buy, values of capacitors, resistors I getting from schematics.Sapphire GPRO X080I manage borrow Rx 6700xt from a friend to make some photos and measurements.Close upFor this one I plug my old m-tester.I identified this SMD:K27E 7 - 2n7002dw - Sot363 - Panjit On schematics from Rx 5700 show 2n7002dwMA 76 6 - MBT3904DW1T1G - Sot363 - On schematics from Rx 5700 show mmdt3904-7WCM 13 - NX7002AK - SOT23 - On schematics from Rx 5700 show 2n7002e1N - SOT-416 - BC847T no longer available to buy On schematics from Rx 5700 show mmbt3904 and is different size Sot363GH15E - AZ1117CH-5.0TRG1 - SOT-223 On schematics from Rx 5700 show az1117ch-5.0FuseB - 0.125AP2 - 2A ? - PPTC Resettable Fuse on Rx 5700 show 1.5ACaps100uF 080522uF 06031uF 04020.1uF 0201Resistors all 04020hm100Ohm * r100 on schematics500Ohm1.1kOhm2.2kOhm10kohm1mohm5mohmCan you check if my identification was correct ?

author: Rabit0
author_rank: Newbie
timestamp: June 29, 2023, 10:42:02 pm
content: EditGPU chip have laser off sense pin for detection if monitors is plugged on all ports, I know because I put all smd *( even freaking 0201) and display ports on board and not worked and only after this I notice it I been fooled due all data signal pins are still connected and have correct resistance values :/But I manage find alternative solution using iGPU on CPU to output image via motherboard HDMI.https://community.amd.com/t5/drivers...11/td-p/593745This register tweak add switchable GPU option that is present in laptops to desktop now my mining GPU work in all games.Some OC I change bios to standard Rx 6700 and UV 1.07V OC +15%TDPhttps://www.3dmark.com/fs/30292816https://www.3dmark.com/pr/2408611https://www.3dmark.com/spy/39352650

author: R_YiDe
author_rank: Newbie
timestamp: April 22, 2025, 01:43:38 pm
content: Thank you, blogger. Through the information you provided, I successfully lit up the display screen
Samsung, QN70Q6DTAFXZA, BOOT LOOP, please help! - Page 1
Forum section: electronics / beginners

author: firepaint
author_rank: Newbie
timestamp: December 12, 2022, 01:55:03 am
content: Please help me solve this mystery! I feel like it could even be a firmware update issue but no way to see a screen yet to navigate to the update menu.I have replaced everything you can find on Ebay, someone said its the panel but the led obviously are working. I think its these driver boards which I did find you can get replacements (maybe)... Here is a video of the issue:View:https://youtu.be/JswMuvDtIR4Thank you so much for any help!-MJ
SATA 5V Power What Commonn to Use? - Page 1
Forum section: electronics / beginners

author: DW1961
author_rank: Frequent Contributor
timestamp: October 07, 2021, 10:03:13 pm
content: Does it matter what common/ground I use on either side of the 5V wire, or should I use the common on the 3V side?After testing, they are all shared grounds/commons, so it doesn't matter what common I use?

author: james_s
author_rank: Super Contributor
timestamp: October 08, 2021, 12:53:27 am
content: They all go to the same place, it makes no difference.