hybridfree/eevblog-posts huggingface dataset:
SORENSEN XPF60-20SP service problem - Page 1
Forum section: electronics / repair

author: teatime
author_rank: Contributor
timestamp: April 26, 2024, 04:08:28 am
content: Dear All,Right now I have a defective SORENSEN XPF60-20SP.I believe the problem at CPX400S/SP MAIN BOARD(PN:35555-5430-3C)But I cannot find the schematic of this board.I found some similar service blog as below:https://www.eevblog.com/forum/repair/sorensen-xpf-60-20dp/https://www.eevblog.com/forum/repair/tti-cpx400a-teardownrepair/but the CPX400S/SP MAIN BOARD(PN:35555-5430-3C) is different.I 'm not sure if there is a board install on TP1 position,I hope some one can find the right schematic of this board.Thank you very much!

author: coromonadalix
author_rank: Super Contributor
timestamp: April 26, 2024, 10:15:22 am
content: http://www.ko4bb.com/getsimple/index.php?id=manualsmay have the xpf series?put xantrex in the search box

author: teatime
author_rank: Contributor
timestamp: April 27, 2024, 01:15:13 am
content: Thank you.But I cannot find the schematics of XPF60-20 at this website.

author: Ugur
author_rank: Regular Contributor
timestamp: April 30, 2024, 10:35:20 am
content: This is actually a product produced by TTI, its counterpart is the CPX400.It is not possible to access the schematics.https://www.aimtti.com/product-category/dc-power-supplies/aim-cpxseries

author: teatime
author_rank: Contributor
timestamp: May 01, 2024, 01:42:39 am
content: Thank you for your attention.CPX series have some different model, like cpx400d and cpx400s,the schematic also different.I send the email to factory for the service manual, but the factory didnot reply me till today.

author: MathWizard
author_rank: Super Contributor
timestamp: May 01, 2024, 03:54:44 am
content: So whats the problem with it ?

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: August 31, 2024, 07:03:13 am
content: Hi teatime,Quote from: teatime on April 26, 2024, 04:08:28 amThe form factor is different but it is more or less the same schematic than for the CPX400D.It seems that the inrush current limitation (R1/RL1) has been removed for the CPX400S.Before fiddling/making mesurements on the main board (PFC), I strongly encourage you to use/buy someelectrical safety gloves, because of the high voltage/significant power present in this area.As far as I can remember, if everything's fine, you shoud find about 390 VDC at the output.Also check for any sparks damage : if the PFC controller goes bersek, the output voltage might raise up to 10 kVan arcing is inevitable.Quote from: teatime on May 01, 2024, 01:42:39 amSame situation here : I asked for buying the CPX400S SM about 1 year ago but got no response (1).AndKeith on hackadayseems to have made the same request quite recently.(1) Don't know why AIM-TTI currently keeps silent. Ten years ago, they sold me several SM for a realy fair price and I was able to successfully repair the defective equipement.

author: mk_
author_rank: Regular Contributor
timestamp: August 31, 2024, 11:42:22 am
content: Quote from: teatime on April 27, 2024, 01:15:13 amSchematics attached.Good Luck to all repairing this powersupply
Sorensen XT 7-6 Repair Help - Page 1
Forum section: electronics / repair

author: ar619
author_rank: Newbie
timestamp: March 19, 2021, 02:57:23 pm
content: Hey EEVblog readers -- I just purchased a used Sorensen XT 7-6 power supply in unknown condition. The physical condition of the unit looks great, but I have observed two issues upon powering up the unit and measuring the output:1) There is an audible buzz that come from the unit. In fact, you can feel vibrations if you touch the bottom of the unit. I'd assume it's coming from the transformer.2) The bigger problem: the output voltage is oscillating at about 130kHz (FYI, I'm in the US 120V/60Hz mains). The mean value of the voltage roughly matches the current voltage setting of the power supply with peak-to-peak oscillation of roughly the same magnitude (i.e. Vpp increases with the output voltage setting). See the attached image for an example with power supply set to 3V.Given these clues, does anyone have a suggestion as to where to start debugging?The following post is regarding a similar unit and has links to schematics and manuals.https://www.eevblog.com/forum/repair/sorensen-xantrex-xt-15-4-power-supply-repair-calibration/msg1415014/#msg1415014In that case faulty capacitors were suspected. Given the specific characteristics of the issues I'm seeing, I'm wondering if there are a few specific capacitors that I should look into first (instead of taking them all out)?Finally, (I know I'm asking a lot) is there any chance fixing problem (2) will resolve problem (1)? Or is it more likely that (1) is just due to an old transformer that needs to be dealt with seperately?Thanks for any help!

author: ar619
author_rank: Newbie
timestamp: March 22, 2021, 06:34:39 pm
content: Pinging this thread...let me know if there is other useful information I can provide. Haven't had a chance to actually open up the device and start probing yet.
Soshine S5 charger - Page 1
Forum section: electronics / repair

author: Gagili
author_rank: Newbie
timestamp: April 25, 2024, 10:17:33 am
content: Dear, in my first post I want to greet you.Don't mind the English, I use what I know and google translator for help.I hope I didn't post the topic in the wrong part of the forum.The problem I have is with the Soshina S5 charger. Instead of the ordered Soshine S5 LiFePO4, I received a Soshine S5 Li ion.There would be too many complications about returning, sending another one, etc.My question is if anyone has a schematic for the Soshine S5 li ion, or a way how or what elements to change to make it adequate for LiFePO4 batteries.I have posted a picture of the received charger in attacments.Thank you for your attention and help.
SOT-23-6 SMD Code identification - Page 1
Forum section: electronics / repair

author: Glenn McKie
author_rank: Newbie
timestamp: August 17, 2025, 11:49:33 pm
content: Hi there, I'm after some help identifying a faulty SOT-23-6 flyback controller. the markings are UI1 & 31A in smaller text.Thanks

author: amyk
author_rank: Super Contributor
timestamp: August 18, 2025, 12:37:14 am
content: Try translating this page to English and see if it helps:https://www.elektroda.pl/rtvforum/topic4129707.html

author: Glenn McKie
author_rank: Newbie
timestamp: August 18, 2025, 01:56:26 am
content: Really helpful
SOT-23 Device Marking Help - Page 1
Forum section: electronics / repair

author: markmcn
author_rank: Newbie
timestamp: July 24, 2020, 02:46:42 pm
content: Hi All,I'm hoping someone can help.I'm working on repairing a SMPS,I've hit a device which is in SOT-23 package which I'm struggling to identify.Looking up the code gives me a few different devices depending on manufacturer.Does anyone it's marked as "N2 C" but the is backward and more like a horse shoe. Photo included.I'm hoping someone might be able to help identify the manufacturer so I can get a datasheet.Thank you for the help and time.CheersMark

author: markmcn
author_rank: Newbie
timestamp: July 24, 2020, 06:12:13 pm
content: So with some delicate desoldering work I managed to get it connected to a component analyser,for any future reference this turned out to be an N-Channel Mosfet not sure who the manufacturer is I would still like to know who's logo that is but this datasheet seems to be closehttp://www.s-manuals.com/pdf/datasheet/b/s/bsn20_r8-2_diodes.pdf

author: fzabkar
author_rank: Super Contributor
timestamp: July 24, 2020, 07:44:48 pm
content: It sometimes helps to identify other parts on the same PCB, just in case the designer has chosen the same manufacturer.

author: kripton2035
author_rank: Super Contributor
timestamp: July 24, 2020, 08:44:11 pm
content: could be a MGSF1N02LT1G

author: thm_w
author_rank: Super Contributor
timestamp: July 24, 2020, 10:53:20 pm
content: Few 20V FETs with the same code, for future reference google "SMD code list" and you'll see some sites/pdfs. Vishay or the ON one above look closest.http://www.s-manuals.com/smd/n2
SOT-23 identification - Page 1
Forum section: electronics / repair

author: OscarM
author_rank: Newbie
timestamp: November 12, 2021, 10:02:00 pm
content: I am trying to identify a SOT-23 used in an MRI coil of ~2006 vintage.I have tried online part marking databases and books.I have come up completely blank. No candidates at all.From the circuit around it I know that this is used to translate from -5/0V logic levels and +5/0V logic levels.Viable parts (in my mind) are N-JFET, some arrangement of prebiased BJTs or depletion mode N-MOSFET.I don't think there is any reason for it to be a custom part and the volumes are so small that custom is unlikely.There is no need for anything special with regard to permeability or magnetic field immunity and these thingsare typically full of standard parts like 74HC' and normal FETs and transistors. (Clearly connectors andcapacitors are a different matter.)I have two of these coils. One works and one doesn't. The pictures attached are of the parts on the two coils.The manufacturer of the coil is one of those that supplies multiple big MRI OEMs so I don't think there is aparticular likelihood of it being from a certain Dutch vendor.Any assistance appreciated.

author: t1d
author_rank: Super Contributor
timestamp: November 14, 2021, 10:27:00 am
content: This is way outside of my knowledge base, but... There is a YouTube guy who goes by the name of "xraytonyb." His channel is (mostly) about vintage stereo amplifier restoration. However, he owns a commercial x-ray machine repair company. Tony is a most excellent person (IMO) and is very gracious in sharing and teaching. He is likely a good source of information, for you.Here is his channel information.https://www.youtube.com/c/xraytonybMaybe you can dig around on his site and find out how to contact him with your question. However, keep in mind two things...- If this piece of equipment can hurt you and you are not a professional electronics person, he may not be willing to help you. And, that is fair enough.- Some professions do not share the tricks of their trade, because it effects their economic livelihood. And, that's fair enough, too.Hope that helps.

author: OscarM
author_rank: Newbie
timestamp: November 15, 2021, 04:59:14 pm
content: 1) Thank you for trying2) Thank you for your concern wrt safety. I take safety seriously.3) I will try to get in touch with xraytonyb. I will report back here if I manage it or learn anything else that is relevant.4) I have changed my mind about the type of device that is in question. It is a simple NPN. Also, it translates from -5/+12V to 0/+5V logic.5) I will also try the folks on reddit.
Sot-23 question - Page 1
Forum section: electronics / repair

author: salviador
author_rank: Regular Contributor
timestamp: March 18, 2025, 06:56:11 pm
content: what is it?

author: Kharn_the_Betrayer
author_rank: Contributor
timestamp: March 18, 2025, 07:12:59 pm
content: What is the board for? Or what kind of circuit is the transistor part of?
SOT23 help for identify unknown device. - Page 1
Forum section: electronics / repair

author: rauldm
author_rank: Regular Contributor
timestamp: May 07, 2020, 07:28:34 pm
content: Hi, I'm repairing a commuted power supply for charging 48 V Pb/acid batteries. it works with 2845B PWM current controller, for main power converter and works also with 2843B PWM current controller for circuit for boost converter. The problem is the 2843B it has connected output to little device in SOT23 format but I cant indentify, I think is a BJT switching transistor but, 2843B is controller for MOSTFET.I atacched a pic.Regards.

author: Yansi
author_rank: Super Contributor
timestamp: May 07, 2020, 07:47:59 pm
content: Likely a 2SA2065. Check your circuit if it fits the purpose and circuit.http://pdf.datasheetcatalog.com/datasheet/toshiba/3087.pdf

author: rauldm
author_rank: Regular Contributor
timestamp: May 07, 2020, 09:23:04 pm
content: Thanks, I think is near to application and circuit type, is a boost converter.

author: rauldm
author_rank: Regular Contributor
timestamp: May 07, 2020, 09:27:28 pm
content: How you found the device?

author: Yansi
author_rank: Super Contributor
timestamp: May 07, 2020, 09:39:27 pm
content: Just by googling "SOT23 marking WK".Not sure about the "4" suffix though, but I could not find any single device with marking of "WK4".You need to understand your circuit first to be able to assess if the part number you have come up with matches the desired circuit it is used in.
SOT23 with marking code A2SHB - Page 1
Forum section: electronics / repair

author: 4cx10000
author_rank: Regular Contributor
timestamp: December 11, 2022, 09:25:01 pm
content: What would you do if you are searching for a SOT23 transistor with marking code A2SHB and by using alltransistors.com you get 11 possible to choose from?Which one would you pick? It probably needs some circuit investigation but still ...

author: gamalot
author_rank: Super Contributor
timestamp: December 11, 2022, 10:00:44 pm
content: It’s Si2303DS

author: fzabkar
author_rank: Super Contributor
timestamp: December 11, 2022, 10:49:33 pm
content: I try to find an image:https://www.google.com/search?q=Si2303DS&tbs=isz:m,itp:photo&tbm=isch

author: amyk
author_rank: Super Contributor
timestamp: December 12, 2022, 04:39:18 am
content: P-channel version of theverycommon Si2302DS (A2SHB).

author: 4cx10000
author_rank: Regular Contributor
timestamp: December 12, 2022, 07:13:13 am
content: Thank you all! My apologies for the typing error in the marking code!It should beA2SHB. Take a moment to check out all the hits for theA2SHBat alltransistors.com and as you see there are in total 11 and 7 with all capital letters. So ... there are 7 possible choices.

author: sleemanj
author_rank: Super Contributor
timestamp: December 12, 2022, 08:25:20 am
content: There is no real way to know exactly which part it is, they are all various manufacturer variants of the "2302" and mark the package the same.Unrealistically you could characterise the part, and see if it meets the specification of some specific manufacturer's part more closely.You could decap the part and see if the die has any clues under microscopy, it proabably doesn't though.The only real way to know, is if you purchased a whole unopened labelled reel of them yourelf, and even then... you got to trust the vendor.

author: 4cx10000
author_rank: Regular Contributor
timestamp: December 14, 2022, 12:54:19 pm
content: Thank you sleemanj!Vice words! It is not that easy to find the original transistor or an equivalent with the help of a marking code with five characters which are the same for a number of other with same package. This Mosfet is in a high power portable rechargeable led work light and on a small bord containing components for charging a 7,4 volts 8800 mAh Li-ion battery as well as some stuff for a USB connector.I have one working board though where I was able to see the transistor, which probably was wiped off the other pcb from a previous repair attempt, and the marking code. So … I guess I will have to take some measurements on the working board and that will hopefully reveal in more understanding in which Mosfet to chose. However, I may give it a go with a SK2302AA or Si2302DS as amyk suggested.
SOT353 SMD identification - Page 1
Forum section: electronics / repair

author: TheMG
author_rank: Frequent Contributor
timestamp: October 25, 2020, 04:55:48 pm
content: I'm trying to identify these components but I'm coming up empty.All 3 are SOT353 package, and on all 3 of them pin 5 is VCC (3.3V) and pin 3 is GND.These are in a part of the circuit associated with RS232 and RS422/485 line drivers/receivers. On the properly working channels, all pins read either 0V or 3.3V. So my best guess is they are some sort of logic gates or something, possibly something to do with switching between RS232 and RS422/485 depending on configuration I would assume.I'm hoping to avoid having to resort to de-soldering known working ones and doing trial-and-error to figure out what type of gates they are. Anyone able to identify these?

author: fzabkar
author_rank: Super Contributor
timestamp: October 25, 2020, 06:08:06 pm
content: SN74AHC1G86DCKT, Texas Instruments, Single 2-Input Exclusive-OR Gate, 2 V to 5.5 Vin, marking AHG, SOT-23-5:https://www.ti.com/lit/gpn/sn74ahc1g86Could the S08D component be a "single 2-Input AND Gate", eg MC74HC1G08, 74V1G08 ?https://www.onsemi.com/pub/Collateral/MC74HC1G08-D.PDFhttps://media.digikey.com/pdf/Data%20Sheets/ST%20Microelectronics%20PDFS/74V1G08.pdf... and could S00B be a "single 2-Input NAND Gate", eg MC74HC1G00, 74LVC1G00?https://www.onsemi.com/pub/Collateral/MC74HC1G00-D.PDFhttps://assets.nexperia.com/documents/data-sheet/74LVC1G00.pdfEdit:NC7S00P5X, On Semi, TinyLogic HS 2-Input NAND Gate, marking S00, SC-88A:https://www.onsemi.com/pub/Collateral/NC7S00-D.PDFNC7S08, On Semi, TinyLogic HS 2-Input AND Gate, marking S08, SC-88A:https://www.onsemi.com/pub/Collateral/NC7S08-D.PDF

author: TheMG
author_rank: Frequent Contributor
timestamp: October 27, 2020, 12:09:38 am
content: Wow! Awesome. I guess what caused my searches to return nothing I incorrectly assumed that the "B" in S00B and S08B was also part of the part code/marking.What I measure steady-state on each of these parts in the working channels does fit the truth table for each one, so I'm fairly certain you have correctly identified them.Now to order the replacement ICs and see if I can get this fried channel (transient/lightning damage) working again.Thanks!
Sound digital 8000.1D repair - Page 1
Forum section: electronics / repair

author: _Emil
author_rank: Contributor
timestamp: July 15, 2022, 03:43:02 pm
content: Hello,I have a SD 8000.1D which a capacitor came loose on. It seems to have broken a mosfet, resistor and a diode. Can i replace just one single mosfet with a new? And i need some help identifying the diode, it's marked H5 and 6 or 9 lying down.Thanks!

author: m k
author_rank: Super Contributor
timestamp: July 19, 2022, 01:53:07 pm
content: Some components are selected, paired and so on.In that case you have to select again and change the whole set.Diode seems to be a 15V zener.
Sound Technology 1000A  no rf output - Page 1
Forum section: electronics / repair

author: Bargainhunter
author_rank: Regular Contributor
timestamp: July 18, 2022, 01:35:10 am
content: My ST1000A stopped working. I do not have any RF output. The meter is working. The voltages on Q30 are 30v collector and 3.5v base and emitter.My curve tracer shows CR20 and CR21 okay. My scope does not show any frequency anywhere in the RF osc.I have attached a schematic.Any help would be appreciated.Thank you.
soundboks 3 - Page 1
Forum section: electronics / repair

author: u666sa
author_rank: Frequent Contributor
timestamp: June 06, 2025, 08:49:25 pm
content: I have soundboks 3 in for repair.Basically it does not turn on, and signs of live. Guy said he bought it used and it worked, but then he went to update firmware and battery died on him.It takes 21 milliamps in completely dead state. 3.3V and 5V rails are present.Shorting reset pins underneath SN sticker on the mainboard drops power consumption to 0 milliamps and then it goes back to 21 milliamps. I'm guessing it boots to some prompt and there is no firmware.I need a firmware dump for this thing. Where to get one? I searched internet and didn't find any.
Soundcraft spirit powerstation, new vs old transistor - Page 1
Forum section: electronics / repair

author: Vicus
author_rank: Regular Contributor
timestamp: July 27, 2022, 02:35:27 pm
content: Hi folks, I have to repair one channel of the power amplifier inside the Spirit powerstation and I want to share with you something that drive me nut for too much time.It's came in with intermittent problem at one channel, low output and in distortion. I restrict the problem to TR204, a MPSA92 pnp transistor. When the proble occur simply probing on his leg solve the problem. So I did think to a dry solder joint but redoing properly the solder didn't solve the problem. So I did think to maybe some sort of corrosion that the transistor suffer. I did replace it with a modern Diotec semiconductor MPSA92 and until it don't burn the power amplifier did work. Now I have some experience and some basis of electronics but this things take to to a rubbit hole that never end. At the beginng I did think that TR204 overheat it's due to some other problem with the load of this stage, I did think that because the Vce it' quite stable, it may vary some tenth of volt in a almost 60V region, and because while heating up the ddp across FR202 increase. I did test almost every single component downstream with no luck untill I decided to swap TR201 with TR204 and problem solved. The trasistor is still burning hot but the ddp acress FR202 is stable and equal to the other channel and that means that also the Ic is stable. So with some electronic basics theory is TR201 and TR204 two current source? So does everything downstram TR204 (under some boundary) not inflencing Ic in TR204?but the main question is why the old motorola work great and the new Diotec doesn't? (In did try more than one transistor)This is the link of the SM.https://elektrotanya.com/soundcraft_spirit_powerstation_mix.pdf/download.html

author: fzabkar
author_rank: Super Contributor
timestamp: July 27, 2022, 05:27:33 pm
content: Quote from: Vicus on July 27, 2022, 02:35:27 pmYes, both transistors are configured as current sources. TR201 is set at 3mA (0.6V / 220R) while TR204 is set at around 10mA.The datasheet for the MPSA92 specifies a max power dissipation of 625mW. However, your circuit could easily dissipate 600mW in the transistor. It seems to me that this transistor is underrated for the intended application.https://www.mouser.com/datasheet/2/115/mpsa92-1164747.pdf
soundtracks PC midi mixer problem - Page 1
Forum section: electronics / repair

author: newtronica
author_rank: Newbie
timestamp: May 07, 2024, 08:07:44 pm
content: Hello Everyone,I've got an old soundtracks PC midi mixer which works fine for all the analogue bits but I'm having a strange problem with the Z80 controlled midi mute automation. I don't know anything about this side of electronics but tried some basic fault finding and doing things like changing all the electrolytic and the shitty ic holders. The weird thing is that after working on the board and say replacing an ic holder when I power it up it works fine and will continue to do so but if I turn the mixer off and on again it doesn't work. I know it uses a few inverter logic chips that start things on low so thought that this may be the cause. I'm sort of just replacing things until it works but no luck so far! It uses a z80 processor with a 4mhz crystal. I just find it weird that after I change/replace things and any residual power is reset it works but next time it doesn't. Any general ideas?ThanksJoe

author: m k
author_rank: Super Contributor
timestamp: May 12, 2024, 07:32:59 pm
content: So input is not dropping or output rising.Missing discharging load can be one, maybe a single small resistor.
Source for 5mm round silicone pushbutton  - Page 1
Forum section: electronics / repair

author: AllenB
author_rank: Contributor
timestamp: October 14, 2019, 08:17:41 pm
content: Hi All,I’ve got a bad pushbutton switch in a Kikusui bench power supply. It’s caused by a tear in the springy silicone “cone” with the black contact in the center. Looks more or less like what’s shown here:https://sc02.alicdn.com/kf/HTB1v3J0LpXXXXc3XVXXq6xXFXXXe/Customized-silicone-rubber-push-button-Switch-Silicone.jpg_350x350.jpgAny guess at what sort of switch I could pull one of these out of? It’s got to be 5mm diameter or very close. Suspect a lot of small, momentary switches have them but hoping to avoid buying a bunch of different ones trying to find the right size piece.Any suggestions appreciated!Thanks,Allen

author: Gyro
author_rank: Super Contributor
timestamp: October 14, 2019, 08:33:32 pm
content: WelcomeYou might want to look around the house for an old TV remote. The ones with soft buttons often have the same sort of silicone cones moulded into a sheet. With some scissors, a craft knife and a bit of ingenuity you might be able to come up with a free replacement plus spares. Just a thought.Otherwise try ebay or equivalent, the magic term is 'conductive rubber contact'.

author: andy3055
author_rank: Super Contributor
timestamp: October 14, 2019, 09:58:53 pm
content: Some old PC keyboards used to come with those as well.

author: jdragoset
author_rank: Frequent Contributor
timestamp: October 14, 2019, 10:20:01 pm
content: Look at Walmart's imported kitchen timers

author: AllenB
author_rank: Contributor
timestamp: October 17, 2019, 09:35:35 pm
content: Thanks for your suggestions. I’ll try pursuing some or all of them!Allen
Source for capacitive touch panel (Navigon 8410/8450 car GPS) or fix? - Page 1
Forum section: electronics / repair

author: Greybeard
author_rank: Frequent Contributor
timestamp: February 17, 2023, 09:23:50 am
content: I've got 2 Navigon 8410 car navigation systems with non/bad responding touch panels.The devices are old, but have very nice GUI, so I'd like to repair them.One touch panel does not respond at all, the other one has a small in-responsive area about in the middle.Problem:I could not find a source to buy these capacitive touch panels:Maybe there's just an open solder joint or similar...Maybe some touch screen expert can help?What's the usual failure causes?
Source for Fluke 867 part - Page 1
Forum section: electronics / repair

author: jsantoro
author_rank: Regular Contributor
timestamp: April 29, 2020, 01:42:14 pm
content: Hi,This is a long shot. Anyone know of a source for the external power jack assembly for a Fluke 867? It's a funky proprietary little thing and Fluke says NLA. It works if I jiggle the plug and I've gone through it Deoxit, bending contacts etc. Last resort is buying a dead unit but they are still not cheap.Thanks, Jim
Source for Logitech camera schematics? - Page 1
Forum section: electronics / repair

author: 0xPIT
author_rank: Regular Contributor
timestamp: April 08, 2020, 02:58:40 pm
content: Hullo,I'm trying to repair another Logitech conference camera (Model V-R0004) and I'm looking for a schematic. It has a power issue, starts up briefly, then shuts down.I know there are tons of laptop schematics available, but is there also a source for peripherals like cameras?Thankspit

author: David60639
author_rank: Newbie
timestamp: April 20, 2020, 03:17:01 am
content: Hey Pit,That looks like a nice camera, one thing I would check first put a multi-meter on the power supply.otherwiseTry and locate the FCCID and check it on the fcc database, They have manuals and other things like that.Hope it helpsDavid
Source for RT9403 - Page 1
Forum section: electronics / repair

author: Traceless
author_rank: Frequent Contributor
timestamp: April 16, 2023, 06:23:03 pm
content: Does anyone know a source where I can order a small quantity ofRichtek RT9403EGV8 (I2C Programmable High Precision Reference Voltage Generator)or any suitable drop-in replacment for those?
source for vintage 2-prong, non-polarized, AC receptacle - Page 1
Forum section: electronics / repair

author: NRE_jwarren
author_rank: Newbie
timestamp: August 15, 2024, 12:00:17 pm
content: looking for a source to obtain the receptacle below from vintage tube amp.1.125" center to center spacing, #6 clearance holes, chassis opening 0.75x0.43".These were everywhere in the 60 and 70s.If you have a supplier that has vintage electronics for sale please provide link. Thanks!
Sourcing long shaft potentiometer - Page 1
Forum section: electronics / repair

author: peetDup
author_rank: Newbie
timestamp: July 15, 2020, 10:46:21 am
content: Hi,I need to replace one of the potentiometer on my scope. It's a 4.7kOhm potentiometer with mounting brackets (I'm not sure this is the correct term) and a 60mm hollow shaft.There is a metal rod which goes from the front panel into the shaft.I've been searching for hours with no success.Thank you

author: bdivi
author_rank: Regular Contributor
timestamp: July 15, 2020, 11:01:02 am
content: Take a standard pot with the suitable value, footprint and shaft diameter and extend the rod as needed.

author: peetDup
author_rank: Newbie
timestamp: July 15, 2020, 11:22:18 am
content: bvidiYes, I can manage a solution for the shaft and use a shaft coupler.But I still can't find a potentiometer with those brackets.Thank you

author: jdragoset
author_rank: Frequent Contributor
timestamp: July 15, 2020, 12:21:05 pm
content: If you can determine the make of the pot, purchase that in the correct value and build the new element/rotor into the existing frame, cover, shaft, etc.

author: Ian.M
author_rank: Super Contributor
timestamp: July 15, 2020, 12:31:48 pm
content: Matching the bracket footprint and height may well be difficult. If you don't get lucky quickly, the easy option if the pot doesn't have a high bandwidth signal on it would be to cannibalize the old pot for the bracket, to mount a new pot pins up, and jumper it down to the board, crossing the track end wires to maintain the same rotation direction.I wouldn't go as far as jdragoset's suggestion unless you are an experienced 'pot butcher'!

author: peetDup
author_rank: Newbie
timestamp: July 16, 2020, 10:26:48 am
content: Found this on ebay.I'm going to give it a tryThank you all

author: jdragoset
author_rank: Frequent Contributor
timestamp: July 16, 2020, 12:12:00 pm
content: Good findTry to preserve some length of the dielectric shaft from the new pot shaft to the front panel shaft, as the new pot shaft may be at an elevated voltage from ground.(intensity/focus)
Sourcing Obsolete Parts - Page 1
Forum section: electronics / repair

author: Yetanother_HAMenthusiest
author_rank: Newbie
timestamp: September 30, 2019, 08:03:10 pm
content: STL, FTP here, so sorry if this is the wrong topic.I'm in the process of repairing a US Interface (Timewave) Navigator soundcard modem that suffered lightning damage to the USB input. I've replaced the fuse and power management chip, but have run into my first obsolete chip in the USB 1.1 hub controller (ATMEL/Microchip AT43301-SU), which doesn't doesn't have a pin-compatible replacement.None of the main US distributors (Arrow, Digikey, Mouser) carry this part, but I was able to find one supplier in China called SICSTOCK.COM that carries this chip.There was one other mention of this supplier, but I've never dealt with them and was wondering if they're a trustworthy source for NOS parts, or if these are cheap clones.Thanks in advance

author: oPossum
author_rank: Super Contributor
timestamp: October 01, 2019, 06:22:51 am
content: https://octopart.com/search?q=AT43301-SU
Sourcing SMD solder flux in Australia - Page 1
Forum section: electronics / repair

author: JoeyG
author_rank: Regular Contributor
timestamp: July 09, 2025, 01:38:40 am
content: What are you using and where are you getting it from?Any good?

author: Kean
author_rank: Unknown
timestamp: July 09, 2025, 02:03:55 am
content: I am currently using ChipQuik SMD491-10M from Digikey, and I like it.Previously I have used ChipQuik SMD4300-10M which I got from Mektronics or Digikey.Mektronics also have SMD291 which I think I used in the past. I didn't see SMD491 on their site.SMD291/491 are "no clean", and SMD4300 is water washable.For rework you will generally have to clean up afterwards, and I tend to spot clean with IPA most of the time instead of a full wash in the ultrasonic.Submersion in the ultrasonic is a problem with buzzers and some other sensitive parts.

author: Kean
author_rank: Unknown
timestamp: July 09, 2025, 03:29:36 am
content: Forgot to mention... as this is in the repair section, I assumed you are working on various random PCBs that you didn't assemble and thus could have used any solder/flux type.If you are doing repairs on your own PCBs that you are assembling, then you might want to get a flux that is compatible with your solder paste.I used to use GC10 paste, but now I'm using ChipQuik TS391SNL which has ROL0 no-clean flux, and the SMD491 flux is also ROL0 no-clean for leaded and lead-free.SMD291 is REL0 no-clean, and intended for lead free. SMD4300 is also REL0 no-clean, but for both leaded and lead-free and water or IPA washable.All of the ones I've used are tacky flux. I'm not a fan of liquid flux for rework.
Sous Vide Thermostat protection - Page 1
Forum section: electronics / repair

author: riccardo.pittini
author_rank: Regular Contributor
timestamp: May 30, 2019, 08:22:50 pm
content: Hi AllI'm repairing a sous vide (immersion water cooker) it has a thermostat that is used for limiting the temperature of the resistive element in case of low water level.Similar to the protection of a water boiler.The thermostat failed, so I need to replace it, there are no codes on the old one so i cannot get the right tripping temperature. What temperature would you select for the protection thermostat?I was thinking 120C or 140C (considering that the temperature of the resistive element will be a bit warmer than the maximum water temperature).https://www.aliexpress.com/item/5pcs-Thermostat-10C-240C-KSD9700-40C-45C-50C-55C-60C-65C-Bimetal-Disc-Temperature-Switch-Thermal/32991291161.html?spm=2114.search0104.3.163.5d4c41f6UGzSwx&ws_ab_test=searchweb0_0,searchweb201602_7_10065_10068_319_10059_10884_317_10887_10696_321_322_10084_453_10083_454_10103_10618_10304_10307_10820_10821_537_10302_536,searchweb201603_52,ppcSwitch_0&algo_expid=3f9a4085-4203-4c37-ab41-d0141dbfcb61-24&algo_pvid=3f9a4085-4203-4c37-ab41-d0141dbfcb61&transAbTest=ae803_5What do you suggest?Thanks

author: soldar
author_rank: Super Contributor
timestamp: May 30, 2019, 10:42:41 pm
content: Quote from: riccardo.pittini on May 30, 2019, 08:22:50 pmDepends on how close thermally speaking it will be to the resistive element. If very close 140, if farther 120, if in doubt 140, if there are plastic parts which can melt 120, etc.Maybe you can measure the temperature under normal consditions at the spot where it goes?

author: timelessbeing
author_rank: Frequent Contributor
timestamp: May 30, 2019, 10:57:05 pm
content: Unless it is under pressure, liquid water does not exceed 100C. Obviously, it would turn into a gas if it did.The whole idea behind sous vide cookers is that you use a lower cooking temps (50-70C). If you wanted to boil the water you would use an ordinary pot.With those two things in mind, I would choose a thermostat that was very close to 100C.
SPA POWER9, Power supply repair - Successfull repair - Page 1
Forum section: electronics / repair

author: David97
author_rank: Contributor
timestamp: August 06, 2021, 10:51:16 am
content: Not a question. Thought I should post a successful repair, in case someone else has this issue, hopefully it will help them out if they stumble on this post online. Just leaving a document of my repair online. I found several documents of people trying to repair this unit. But they could not due to part numbers being scrubbed off, or components destroyed to a point where they could not read the numbers.Disclaimer - Messing about with power supply is dangerous. Capacitors can hold charges hours. Even with the device unplugged, there is the potential for a nasty, or fatal shock if you don't take precautions. If you don't feel comfortable with this disclaimer, then just spend the $ to buy a new unit.After any test, leave it disconnected for several hours, and make sure you short out the caps to discharge them before working on the unit. If you don't know what you are doing with electronics, then this is not a thing you should be messing with. There is a lot that can go wrong.A easier and safer option would be to just install a equivalent rated PSU in the box.During the testing, I was sure to never touch the board. I had a light wired in series, as a ballast. So if the unit went dead short, it would not trip the breaker or blow a fuse.This PSU was dropped into my hands after one of my mates spa pool stopped working.The first thing I noticed was the SMPSU IC was blown. The IC had a crack in it, and a obvious skid mark. The part numbers were scrubbed off. I reverse engineered it, and replaced with a TOP247YNhttps://www.digikey.co.nz/product-detail/en/power-integrations/TOP247YN/596-1078-5-ND/865354The output rectifier diodes were shorted. Part number MBR25100CT. I replaced with a higher rating, using MBR30100CT. Since these diodes blew, there is the potential that the capacitors on the output have seen some AC, and should be replaced too.https://nz.element14.com/taiwan-semiconductor/mbr30100ct-c0g/schottky-rectifier-100v-30a-to/dp/3519354?st=schottky%20rect%20100v%2030aAt this point, the PSU powered up, but the voltage was way too high. I adjusted the pot, but it fell apart when adjusting. So I replaced with another 1K trim pot.The voltage was still not being regulated properly, so I tested the voltage reference TL431 and it tested fine. I tested the optocoupler EL 817, and it was faulty. I replaced with a equivalent opto, and the PSU was now regulating, and operating properly.As a final thing, I ultrasonically cleaned the board, calibrated the voltage. And then applied conformal coating. Since there was some minor signs of water ingress on the bottom of the board, wanted to seal and protect against future failures. I sealed up the unit. And hopefully it will be good for the future.
Spare HP LogicDart for parts?  LCD - Page 1
Forum section: electronics / repair

author: bitslip
author_rank: Contributor
timestamp: October 24, 2021, 11:47:47 pm
content: Hey all,I suspect it's super unlikely but I'm hoping to find someone who might have a non-functional or donor HP LogicDart that I can salvage the LCD from. If you have a fully working LogicDart and you're willing to sell it (I won't cannibalize it), let me know as well.I took mine out of its protected storage case only to find the LCD seems to have broken. Surprisingly it still "works" but the display is very hard to read with the purple blob syndrome.I'm 99% it's a custom LCD that's 131x64 resolution, derived from the one used in the HP48 calculators but a different display without the calculator's annunicators. I could reverse engineer the display controller, create an FPGA design to drive a modern LCD (128x64?) but that'd be a huge time investment on this. This unit actually means a lot to me, I was fortunate to get it almost 20 years ago and I'm really saddened to see it in its current state.

author: jchw4
author_rank: Regular Contributor
timestamp: October 25, 2021, 01:49:54 pm
content: I guess the LCD is fine. Just replace the LCD polarizer.Search how people have done it with Tektronix THS 710/720/730 scopes on this forum.Upd: you can also google for "nintendo lcd polarizer replacement", there are many repair videos for the old Gameboys with exactly the same issue.

author: Kean
author_rank: Unknown
timestamp: March 21, 2022, 10:43:12 pm
content: I have a similar display issue on my Logic Dart, although not as bad.I removed the polarizing filter layer and put a new one on, but it didn't really help. Well in fact I cracked the top layer glass, so it made things slightly worse along the right edge.As I had a dead HP48GX and a HP38G in pieces, so I tried an LCD swap but it didn't work. No display at all.There is almost certainly a different connection layout due to the annunciators.

author: free_electron
author_rank: Super Contributor
timestamp: March 21, 2022, 11:59:16 pm
content: oohhh. i have one of those too. no i'm not selling it... they only made that for a short time. i got mine through a giveaway. buy 34401 multimeters and have a chance to win one...

author: Kean
author_rank: Unknown
timestamp: March 22, 2022, 12:54:27 am
content: Forgot to attach pics. These are before and after polarizing film change.I was quite careful, but the damage I caused is pretty obvious. And the damaged area actually now has better contrast than the rest of the display.
Speaker cracking on high vol - Page 1
Forum section: electronics / repair

author: hpibmx
author_rank: Regular Contributor
timestamp: May 19, 2023, 10:41:04 am
content: Hi,I’ve got Logitech speakers z906, after not using for about 6 month 2 of the small speakers have this cracky sound when it’s increased, I opened one up and saw this is there anyway to get this fixed? Or not at all?Thank you.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 19, 2023, 11:28:14 am
content: Google speaker repair kits and you will find replacements available for many speaker sizes and models. I have had good luck repairing large speakers (woofers) using these kits, but have never tried anything smaller than about six inch (15 cm).The process is tedious and fiddly, and I suspect more critical dimensionally on small speakers. I would also suspect more impact on sound in speakers used for higher frequency sounds.

author: Gyro
author_rank: Super Contributor
timestamp: May 19, 2023, 01:01:38 pm
content: On the upside, having the 'bullets' on the centre pole pieces rather than dust caps would make it easier to shim to centre the voice coils. Something that small is going to be tricky though. The first thing is to get rid of all the dust that's collected in the gaps.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 19, 2023, 01:21:44 pm
content: your speaker suspension is damaged ?? the foam is cracked or cut .... if i read pictures correctlyif you push slowly the speaker cardboard equally down and you hear gritch, physical noise meansyour voice coil is touching the frame = damaged speaker

author: jonpaul
author_rank: Super Contributor
timestamp: May 19, 2023, 02:12:07 pm
content: old foam if new you got scammed if old/used/epay they are many years oldj

author: Coordonnée_chromatique
author_rank: Frequent Contributor
timestamp: May 19, 2023, 03:09:49 pm
content: Hello,Most foam surrounds last only around ten years since the rice kellogg's loudspeaker loudspakers had been equipped with and no one is talking oubout the "planned obsolescence"You can find some replacement loudspeakers driver units here :https://www.visaton.de/en/products/drivers-accessories/fullrange-systems

author: AzGuy
author_rank: Newbie
timestamp: May 20, 2023, 08:01:25 pm
content: I'm sure by now you've had a lot of good replies.I've been fixing the foam on my speakers for a while. They are a few years old and the foam is cracking on them. There are several places to get new foam replacements to do the task yourself. It's messy and tedious, but you can do it. I went towww.simplyspeakers.com. They have an assortment of sizes of replacement foam, adhesive, and instructions. They have measurements to help also. If you run into an issue, email the company. I did and got a guy that was really helpful. Good luck.
speaker problem - Page 1
Forum section: electronics / repair

author: hummerjanne
author_rank: Regular Contributor
timestamp: November 14, 2023, 03:50:43 pm
content: speaker problem I don't understand. The issue is this: When you press on the speaker, you hear a sound and after a few minutes it disappears. There are 2 speakers. When you press on it, the sound comes and then it disappears by itself. What causes this problem?Let me explain in short, so that you can understand, the computer has speakers, but the sound disappears. There are speakers under the plastic. When you press, the sound comes from the plastic, then it disappears.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: November 14, 2023, 04:08:47 pm
content: Could be a loose or broken wire, or dirty connector. When you press on it a connection is made, which goes away as the material relaxes back to its rest state. Another possibility is a twisted frame on the actual speaker inside the speaker boxes pictured. The twisted frame prevents the voice coil from moving, but it is temporarily freed when you push on it. Motion from the sound works it back into the stuck position.There are other possibilities, but thinking of these types of things will guide you in doing tests to narrow it down.
Speakercraft MZC-66  - Page 1
Forum section: electronics / repair

author: Watcher
author_rank: Contributor
timestamp: October 22, 2022, 02:31:48 pm
content: I have a speakercraft MZC-66 multiroom amplifier since 2012.Recently when turned on by the main front switch, all zones get activated and source one gets selected for all zones.The keypads are unresponsive and no control is possible.I did tried to connect to the system via RS232 for settings / firmware check but no connection is possible either.It seems to me that the problem is micro-controller related since all the amplifiers themselves work but I have no idea how to troubleshoot any further.Anybody has any experience or advice for this unit?Thanks!

author: Grandchuck
author_rank: Super Contributor
timestamp: October 22, 2022, 08:36:22 pm
content: I have no experience with this unit but will ask if you have checked the power supply voltages?

author: Watcher
author_rank: Contributor
timestamp: October 23, 2022, 06:12:49 am
content: HiThanks for your message.No. I haven't opened up the unit inside.As I said, all amplifier stages seem to work fine (source 1 plays in all zones)and in addition the selected Zone 1 is illuminated in all keypads.It is as if there was a programmed command to turn on all zones and select Source 1 at startup.I wonder if the firmware was somehow corrupted. However the only documented method for firmware upgrade is through the RS232 port which doesn't work either..I have also emailed the manufacturer hoping for guidance...

author: David_AVD
author_rank: Super Contributor
timestamp: October 23, 2022, 09:04:49 am
content: I'd be opening it up and casting an eye over the power supply first.What type of serial connection did you try? Did you have to make up a cable for it?

author: Watcher
author_rank: Contributor
timestamp: October 23, 2022, 01:51:54 pm
content: I am waiting for the response of the manufacturer and if i get no help from them, I will then open it up as you said.The unit has at the back a respectable for 3.5mm 4-way (the type usually used for headphones) connector giving access to an RS232 port. I made a cable for this when I first installed it in order to program it and it worked fine.I used the same cable now. So I don't think the problem is related to the cable.
Spectra Physecs Quanta Ray  - Page 1
Forum section: electronics / repair

author: davedrosen
author_rank: Newbie
timestamp: October 21, 2024, 01:07:51 am
content: Greetings, I have a quanta ray power supply and head for a DCR series yag. I also have a lab version gcr head. I had to cut the umbilical cord for the DCR to get it and the supply into my verhicle. I am going to hook back up the umbiical cable but want to put connectors on them. My problem is I can't find the pinout of the GCR head--which is already connectorized. If anyone had the schematic of the head or supply it would save me a boat load of time. Thanks in advance.