hybridfree/eevblog-posts huggingface dataset:
HP 8590 series CAL failed - Page 1
Forum section: electronics / repair

author: Daxxin
author_rank: Regular Contributor
timestamp: October 15, 2017, 07:52:53 am
content: While CAL FREQ is done without problems, with CAL AMPLTD attempting i get ''CAL: RES BW AMPL FAIL'' service manualsays require realignment of crystal and LC bandwidth filter at chapter 2 , boards A11 and A13but following the instruction look like there is errors . Wich is the correct sequence about jumper?

author: blackbird
author_rank: Regular Contributor
timestamp: October 15, 2017, 08:51:55 am
content: For which sa are these instructions? They differ between 8590a, 8590b and subsequent versions.

author: Daxxin
author_rank: Regular Contributor
timestamp: October 15, 2017, 09:50:00 am
content: it's about 8590E series , there no errors i didn't get that need to put all three jumpers at start of proceduresnot one per timethat's my fault , anyway i'm still having trouble with CAL OUT seems its not enabledwhen i switch on sa , and even if i try to CAL AMPLTD i get 'CAL SIGNAL NOT FOUND'If i start CAL FREQ fisrt then the CAL OUT signal appear ..why?anyway it look not good enough to complete the CAL AMPLTD.According with the manual settings for Crystal and LC alignment (freq 300Mhz , span 200Khz , BW 30Khz , AMPLIT. -20dBm)when jumpers inserted signal appear worst.

author: Daxxin
author_rank: Regular Contributor
timestamp: October 15, 2017, 04:16:01 pm
content: Following this steps found in another forum everything okCAL AMPLTD and FREQ completed and storedPresetFrequency -2001 HzAmplitude, More 1 of 2Input Z 75-ohm (50-ohm in my case)Amplitude, Scale Log Lin (Log), More 1 of 2 Amptd Units dBmVAmplitude, Scale Log Lin (Lin), More 1 of 2 Amptd Units dBmVCal, More 1 of 4, More 2 of 4Service Cal, Stor Pwr On UnitsI would then default the calibration data by doing the following:PresetFrequency -37HzCal, More 1 of 4, More 2 of 4Default Cal Datathen CAL routine.

author: analogRF
author_rank: Super Contributor
timestamp: April 03, 2018, 02:02:22 pm
content: Quote from: Daxxin on October 15, 2017, 07:52:53 amI am having the same problem with 8596E. How do you make those crystal short jumpers?
APC Smart-UPS 1500 always overload - Page 1
Forum section: electronics / repair

author: crazy_driver
author_rank: Contributor
timestamp: October 19, 2017, 08:53:49 pm
content: Hi,Can someone help with a suggestion?This ups was given to me in unkown condition, i put 4 batteries in and it's always on overload.I found a few videos talking aboud dead capacitors that would cause that on APC ups, so i removed all the caps and tested them with a Mtester.I only found two 330uF with a value around 300 all the others were close to spec.I tested the HRF3205 Mosfets all had similar values.The Mtester can't test the LM317T voltage regulator that i removed last or it's defective.So any ideas or just buy the new stuff and do the double power conversion while at it?https://www.eevblog.com/forum/projects/cool-tutorial-converting-an-apc-ups-into-a-powerful-sinewave-inverter/

author: LuisHertz
author_rank: Newbie
timestamp: March 30, 2018, 10:24:01 pm
content: Can you fix It?

author: coromonadalix
author_rank: Super Contributor
timestamp: March 31, 2018, 11:24:23 pm
content: apc in 1kw models had capacitors problems and some noise on op amps in the charging circuit ?? i think tantalum caps where at fault too ?

author: BradC
author_rank: Super Contributor
timestamp: April 01, 2018, 12:55:09 am
content: That's a late 3G unit. Have you checked the config to ensure it knows what it is? One peculiarity with the 3G units is they keep their config in an external serial eeprom, and it's not unheard of for it to lose its mind and default to believing it is a US 750VA unit. That screws all the configs and calibration constants and causes it to think it's overloaded, boil the batteries and other nasty things.Read up on how to config those units, put a serial cable on it and check before you go suspecting the hardware. Or of course you could just dive in and start ripping apart, shot gunning parts and making wild guesses

author: oldway
author_rank: Super Contributor
timestamp: April 02, 2018, 01:47:50 pm
content: I know nothing about APC ups, I worked with industrial UPS AEG / SVS from 10Kva's to 400Kva's.....So I don't know if what I'am writing can help.....I have had the same problem (indication of overload even without any load) and it was a faulty Hall effect current sensor LEM.Is there someting like this in APC ups ? I don't know but beter to check.....

author: BradC
author_rank: Super Contributor
timestamp: April 02, 2018, 02:06:43 pm
content: Quote from: oldway on April 02, 2018, 01:47:50 pmNo, the SmartUPS series use a current transformer which is conditioned and fed into the ADC.
Removing HP 3478A front bezel and panel - Page 1
Forum section: electronics / repair

author: rhb
author_rank: Super Contributor
timestamp: March 31, 2018, 12:57:06 am
content: I've looked at the service manual and the instrument. I can't tell if I don't understand it or it's just being stubborn.Does it come off towards the front or the back? I did a search and found two teardown videos, but neither removed the front panel or bezel.

author: marty
author_rank: Contributor
timestamp: March 31, 2018, 08:26:09 am
content: Page 5-2 n,o,p,qsays front, towards you. so basically free the tabs, push the board towards you until tabs cleared, squish the sides.If you have more problems I can disassemble mine with a video.

author: rhb
author_rank: Super Contributor
timestamp: March 31, 2018, 03:03:25 pm
content: Thank you. That's much better than the description in section 6. I was scanning from back to front when I came across the very terse description in section 6. It's also more involved than I want to do just to clean it, at least for now. I will likely want to add an LED backlight in some manner eventually.

author: Stray Electron
author_rank: Super Contributor
timestamp: April 01, 2018, 02:13:21 am
content: I haven't had a 3478 apart but I have taken other HP meters and power supplies with that type display apart and what I had to do was to take the case off then remove the screws that held the front panel section to the rest of the chassis. Unplug the cables and remove the FP section. Then look along the top and bottom edges and you'll see a couple of slots. Inside are plastic latches that stick straight back from the front bezel and that have hooks on the end. The hooks latch into the slots on the FP frame. You have to very carefully reach into the slots and press down from the top and up from the bottom, and release the hooks. The arms of the latches are easily broken and it's handful to get all four of them to release at the same time. But once you do, you can slide the bezel out from the front. On mine, once I had the bezel off I actually put the unit back together without a bezel and when I received the new bezel I just snapped it into place from the front.

author: rhb
author_rank: Super Contributor
timestamp: April 02, 2018, 01:53:00 am
content: On the 3478A you have to remove the board from the chassis. Then you separate the front panel. It's far more work than I thought. I opted to clean in place. It looks much nicer now.
Videologic DAB Tuner - station memory not retained long. - Page 1
Forum section: electronics / repair

author: FrankE
author_rank: Regular Contributor
timestamp: April 01, 2018, 06:36:02 pm
content: I've a standalone DAB tuner which I'm using until I an find my remote control for my Naim streamer.I only listen a couple of days a weeks so I power it down most of the time.There's a supercap stores the station settings a Panasonic SG 5.5V 1Fhttps://uk.rs-online.com/web/p/electric-double-layer-capacitors/8690771/I logged the voltage over 24 hours and it has gone from 3.12V down to 2.46V.Normal or worth swapping ut with a 1.5F supercap?https://uk.rs-online.com/web/p/electric-double-layer-capacitors/8690783/Hmm the 3.6V ones are 2000h, the 5.5V ones 1000h.
Fluke 73 Resistance issue over 50k.  - Page 1
Forum section: electronics / repair

author: ddwilson
author_rank: Contributor
timestamp: April 01, 2018, 07:47:38 pm
content: I have a fluke 73 series iii that when it was given to me R1 (fusible resistor) was blown. Replaced it and now the meter works great on voltage, current and lower resistances.But the highest resistance it will go to is just above 50k, will not go above that. Any suggestions?Thanks,Doug

author: coromonadalix
author_rank: Super Contributor
timestamp: April 01, 2018, 11:09:32 pm
content: please dont start multiple threads about the same unit

author: ddwilson
author_rank: Contributor
timestamp: April 02, 2018, 01:16:20 am
content: this is not about the same unit I am working on two separate meters. I know better than that

author: retiredcaps
author_rank: Super Contributor
timestamp: April 02, 2018, 02:24:54 am
content: Check to make sure the PTC is around 1k ohm and the MOVs are open circuit (resistance wise).

author: ddwilson
author_rank: Contributor
timestamp: April 05, 2018, 02:14:06 pm
content: Retiredcapsthanks for the help both of the MOVs were not shorted but one was 33k the other 90k replaced both of them. Checked the meter with my calibrated tester works perfect now.Doug
Need Schematic: Todd Engineering PC75 "Power Source"Power Supply/battery charger - Page 1
Forum section: electronics / repair

author: innkeeper
author_rank: Unknown
timestamp: March 23, 2018, 01:42:48 am
content: I Need Schematic for Todd Engineering PC75 "Power Source" Power Supply/battery chargersearched the web so far no joy...its likely that the schematic for other models would work like a pc40 or pc45 etc as it seems to be built modularly to increase the current capacity.thanks

author: innkeeper
author_rank: Unknown
timestamp: April 01, 2018, 01:49:33 am
content: Anyone have Schematics for any of the TODD Engineering power supplies?
VFD Display Dim At Power Up - Page 1
Forum section: electronics / repair

author: kiheiman
author_rank: Contributor
timestamp: March 22, 2018, 03:03:10 pm
content: I have a friend with a Kenwood TS-870 radio. The VFD display is dim at power up. The display gradually gets brighter. After about 10 minutes, the display is very bright. I am assuming that the VFD is OK. I have had HP test equipment where some segments on the VFD display were dim - due to long hours of use.I assume that something is heating up on the display board. Earlier models of this radio had problems with leaking electrolytic capacitors on the display board.Any recommendations on what I can check for VFD voltages?

author: texaspyro
author_rank: Super Contributor
timestamp: March 23, 2018, 03:25:55 am
content: It could be the cathode (filament) in the VFD has weak emission and is taking a while to warm up enough to throw off enough electrons to light the display. This is a common wear-out mechanism of VFDs.

author: shakalnokturn
author_rank: Super Contributor
timestamp: March 23, 2018, 12:34:38 pm
content: In the case of a VFD check filament voltage of course, however most of the time this is a symptom of bad small (22-100µF / 50-100V) electrolytics on the cathode-anode drive voltage (usually 20-30V).Looking at the TS-870Sservice manual the display is an LCD with CCFL backlight (or electroluminescent sheet) in that case I'd suspect a weak CCFL, but it is also worth checking capacitors around the inverter.

author: texaspyro
author_rank: Super Contributor
timestamp: March 23, 2018, 04:16:26 pm
content: EL backlights are very well known for their finite (and usually rather short) lifetimes. But, they don't have a warmup change in intensity.

author: james_s
author_rank: Super Contributor
timestamp: April 01, 2018, 12:31:02 am
content: CCFL backlights certainly do get dim with age though and require some time to warm up. The first step here is to determine exactly what sort of display this is and if it has a backlight what type.
Sony trinitron kv-27fs100 issues - Page 1
Forum section: electronics / repair

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: March 31, 2018, 01:04:02 am
content: I have a kv-27fs100 flatscreen sdtv crt. I have had it since the beginning of time (built in 2002).There have been some issues regarding it.A geometry error seen towards the bottom.There is a convergence issue towards the top.I have tried degaussing by unplugging, turning on and off, and repeating (I tried a few times). Anything else that can be done?

author: Shock
author_rank: Super Contributor
timestamp: March 31, 2018, 03:32:02 am
content: What is the exact source and specs of the input signal and what other signal sources does it occur on?

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: March 31, 2018, 03:40:26 am
content: These were captured on two signals, one an intellivison flashback 240p composite, and the other component 480i ps2. Both had the same effects.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 31, 2018, 04:05:59 am
content: I had one of these. This is the "funhouse mirror" effect. The dynamic convergence circuits required to keep the beam focused on a flat screen need to be tuned manually. You do this from the remote control with secret service codes.Good luck finding them, I no longer have the TV or the information!I think this is it:http://www.neo-geo.com/forums/showthread.php?248996-Sony-WEGA-Trinitron-CRT-TV-service-menu-Tips-Tricks-and-settings-suggestionsIt was no fun adjusting this gigantic mess of interacting and mutually defeating adjustments....

author: floobydust
author_rank: Super Contributor
timestamp: March 31, 2018, 05:11:49 am
content: I'd adjust the focus voltage first, and see if the screen voltages need adjusting.I vaguely recall the convergence is dependent on electron velocity.

author: drussell
author_rank: Super Contributor
timestamp: March 31, 2018, 05:45:12 am
content: I don't think you can adjust the convergence on most of the 27 inch models. It is supposed to just be pre-adjusted physically during assembly (maybe magnets?) and never require adjustment if everything else is working properly. Did this issue come on slowly over time or did it just suddenly appear without warning?So, yes, I agree with the above suggestion to check voltages and check the operation of absolutely everything else first because otherwise it may actually be a physical tube problem.

author: mzacharias
author_rank: Frequent Contributor
timestamp: March 31, 2018, 10:26:35 am
content: Most of these had rubber wedges between the yoke and the tube itself, on which the glue dried up or they shrank a bit with age - whatever. The result is the wedge(s) fall down to the board below and the yoke tilts slightly. If you can find them and re-insert them as they were, should clear up your problem.Seems likely to me this is your problem.

author: james_s
author_rank: Super Contributor
timestamp: April 01, 2018, 12:27:16 am
content: That looks similar to the effect you can get when capacitors in the vertical output section start to fail. Does the symptom improve as the TV warms up?
Data recovery from an in-situ eMMC chip - Page 1
Forum section: electronics / repair

author: rasteri
author_rank: Contributor
timestamp: March 29, 2018, 10:55:48 pm
content: Hi! I'm a long time lurker first time poster who wants some advice on analogue circuit design, but I thought it's only fair to contribute something firstHere's my video showing a practical and (most importantly) cheap approach to recovering data from an eMMC chip without desoldering it, in this case while it's attached to a crappy laptop. The same approach could be used for smartphones and tablets I suspect, if you can find boardview files for them.There's no new ideas here at all really, the basic approach comes from the "Hacking Hardware with a $10 SD Card Reader" talk by exploitee.rs at Blackhat 2017 and it's something data recovery companies often do but charge a lot of money for.I'll post my questions in another topic

author: JeffreyLatter
author_rank: Contributor
timestamp: March 31, 2018, 12:35:55 pm
content: Great video - Not sure, what the best part, the technical stuff or the great musical part in the end...Definitely something, I'll keep in my mind, if never needed.
Help me please with this smd IC? - Page 1
Forum section: electronics / repair

author: engavi
author_rank: Newbie
timestamp: March 29, 2018, 03:46:35 pm
content: HiCan someone help me to identify this smd 10 pins MSOP ?I can not find any accurate information..Thanks

author: Chriss
author_rank: Frequent Contributor
timestamp: March 29, 2018, 03:48:54 pm
content: In what device is this ic?Sent from my GT-I8260 using Tapatalk

author: engavi
author_rank: Newbie
timestamp: March 29, 2018, 03:57:23 pm
content: hi Chriss,thanks for your interest.It is a preamp and polarization module of a microphone.I suppose that is a double linear voltage regulator, but i am no sure wicht of them.Regards

author: gamalot
author_rank: Super Contributor
timestamp: March 29, 2018, 03:59:24 pm
content: max1556https://datasheets.maximintegrated.com/en/ds/MAX1556-MAX1557.pdf

author: mbless
author_rank: Regular Contributor
timestamp: March 29, 2018, 05:40:50 pm
content: Quote from: gamalot on March 29, 2018, 03:59:24 pmHow are you finding these so readily?

author: gamalot
author_rank: Super Contributor
timestamp: March 29, 2018, 05:46:01 pm
content: Quote from: mbless on March 29, 2018, 05:40:50 pmSearch in taobao.com by using silk screen as keyword, learn some if you don't know any Chinese.??

author: engavi
author_rank: Newbie
timestamp: March 30, 2018, 12:28:58 pm
content: Gamalot, thousands thanks for your help.Yes, it is that!!. The encapsulation is effectively 10-TDFN, I thought it was 10-MSOP.It is a pity do not know Chinese. Do you know if there is something similar to taobao.com in English? It is a very useful informationI only know t turuta.md and you have to become a member.Regards

author: gamalot
author_rank: Super Contributor
timestamp: March 30, 2018, 01:17:31 pm
content: Quote from: engavi on March 30, 2018, 12:28:58 pmI was just kidding, actually you don't have to know Chinese.https://www.eevblog.com/forum/chat/(tips)-how-to-identify-smd-devices-from-the-marking-codes/

author: engavi
author_rank: Newbie
timestamp: March 31, 2018, 11:53:45 am
content: Thanks again for the inconvenience that you have taken.Now I understand how it works!!It's amazing the information you can get..Best greetings
Sony ICF-C270 alarm clock wireless set - significant water damage. - Page 1
Forum section: electronics / repair

author: FrankE
author_rank: Regular Contributor
timestamp: April 03, 2018, 11:40:55 pm
content: I have a water/ humidity damaged clock wireless on the bench.Much of the tinning is gone on some passives most notably on disc caps and resistors (if there was any). Solder side is fine.The LCD doesn't illuminate.The wireless works on AM & FM, so I assume the CXA1019S is fine.The shaft from the volume dial which inserts into the volume pot (marked "503") sheared off. A plastic flosser is just about the right size to cement on to it.There's a glass diode near to the input from the transformer secondary which only has one (k) leg it's orange on the inside and has a blue band on the outside, k side. I suspect this is where the LED d7 segment driver takes it's supply from.What is the colour coding in use on glass diodes?

author: coromonadalix
author_rank: Super Contributor
timestamp: April 04, 2018, 12:40:52 am
content: some google fuu will help:https://servicemanuals.us/sony/audio/icf-c270-icf-c270l-sm2/download.htmlhttps://elektrotanya.com/sony_icf-c270_c270l_sm.pdf/download.html-------------- works best try this one first

author: FrankE
author_rank: Regular Contributor
timestamp: April 04, 2018, 01:29:45 pm
content: Thanks, I saw a bunch of manuals but registration required.Electro tanya one is accessible, cheers.Got 50 1SS119 diodes cheap on ebay

author: johnkenyon
author_rank: Regular Contributor
timestamp: April 05, 2018, 10:04:31 am
content: Quote from: FrankE on April 03, 2018, 11:40:55 pmThe resistor colour code is always a good place to start./John

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: April 07, 2018, 09:06:44 am
content: John, Can you elaborate on this, please?BT

author: Chris56000
author_rank: Frequent Contributor
timestamp: April 07, 2018, 10:03:45 am
content: Hi!Diodes are sometimes colour–coded to denote their type as it's slightly more durable than coding with numbers – for example, a 1N4148 general purpose diode is coded yellow (first band much wider to Indicate cathode,), then brown, yellow, grey = wide yellow = 4, brown = 1, yellow = 4, grey = 8.Another commonly found example is the Philips BAW62, with a light blue body and a thin blue band and thin red band close together at the cathode end to denote the '62'.Colour–coded 1SS119s would be coded two brown and one white band, and so on.However some Japanese diodes (typically "Rohm") used ONE colour band at one end to denote cathode, and also the type of diode, one scheme in use being:–BLUE cathode band – standard recovery. GREEN cathode band – fast recovery, RED (sometimes WHITE) cathode band – Schottky rectifier, ORANGE cathode band – zener plus a marking to indicate Vz, data sheets need to be referred to for these types of devices as there's many variations!If youy'e stuck, show us.a picture and any of us on this Forum'll be glad to help!Chris Williams
Hitachi V-1085 oscilloscope spare parts available - Page 1
Forum section: electronics / repair

author: g3
author_rank: Newbie
timestamp: February 01, 2018, 06:35:52 pm
content: Hello,I recently disassembled a Hitachi V-1085 oscilloscope. No chance to repair, CRT has a crack and possibly the high-voltage transformer is also defective.So I thought I'll announce that I have some spare parts. Tell me if you need anything.

author: TonyLangley
author_rank: Newbie
timestamp: March 30, 2018, 07:33:59 pm
content: Hello EEV Forum member:I have an Hitachi V-1060 Scope, The LOPT ( Fly-back high voltage transformer ) has shorted turns. I believe the V-1085 uses the same transformer. Can you give me any details on why you believe your transformer is faulty. Any other members who have such a transformer please join in.Thank you,Tony
Unknown element - Page 1
Forum section: electronics / repair

author: iceman
author_rank: Newbie
timestamp: March 29, 2018, 09:06:52 pm
content: Hello. This is my first post, so I hope I'm doing everything rightMy daughter has inline skates with LEDs that flash when she moves. There is a circuit in each one of the skates. On one skate LEDs work as expected, on another one - no light. I've inspected the circuits and found that an "element" is connected to PCB using one leg and one very thin wire. On the non-working circuit this wire is broken. There are absolutely no marks on the element nor on the PCB. I'd like to replace this element, but I have no clue what that is. Hence the question, does anyone know what that element is? It is a black cylinder, which looks like capacitor. I've attached the pictures of the working PCB and market the broken wire (broken on another PCB) with the red circle.

author: ataradov
author_rank: Super Contributor
timestamp: March 29, 2018, 09:34:48 pm
content: That may be a vibration/orientation switch. I guess the thin wire is to make the sensor have only one rigid support.

author: iceman
author_rank: Newbie
timestamp: March 29, 2018, 09:45:40 pm
content: This is an interesting idea. This element is fixed with the hot glue on the other side though. I thought that vibrations are detected using gyro on the other side of the PCB. Of course, I'm not sure that this is gyro, there are no marks on it.

author: ataradov
author_rank: Super Contributor
timestamp: March 29, 2018, 09:49:32 pm
content: Try to measure continuity of that element while rotating the board in space (on a working unit). Whatever it is, I assume it just has a dry contact.

author: doktor pyta
author_rank: Frequent Contributor
timestamp: March 29, 2018, 10:16:55 pm
content: a tilt switch?https://www.funduinoshop.com/Tilt-switch-SW-520D

author: ataradov
author_rank: Super Contributor
timestamp: March 29, 2018, 10:18:40 pm
content: Quote from: doktor pyta on March 29, 2018, 10:16:55 pmThat's what I was thinking. But why would it have one pin made of what seems to be an enameled wire? That just seems strange.Although this one has asymmetric legs as well:https://www.adafruit.com/product/173This looks like a replacement part.

author: Andy Watson
author_rank: Super Contributor
timestamp: March 29, 2018, 10:27:34 pm
content: Prise-off the broken device and look for a part number. If you cannot find a part number try searching for SW 18010 on ebay - it should return something that looks very similar.

author: iceman
author_rank: Newbie
timestamp: March 30, 2018, 04:14:15 pm
content: I cannot find the part number on the outside of that element, but indeed, when I search for SW 18010 - I get very similar parts. I'll order some of those and give them a try. Thanks!And thanks everyone for help! As I mentioned, this was the first time I write on this forum, and I'm impressed on how fast I got help.

author: PA0PBZ
author_rank: Super Contributor
timestamp: March 30, 2018, 05:50:43 pm
content: This is why there is one very thin wire:
New DIY STC T12 Soldering Station - Works but got a small issue - Page 1
Forum section: electronics / repair

author: RayRay
author_rank: Frequent Contributor
timestamp: March 29, 2018, 10:22:55 pm
content: Hey guys.I've built a new soldering station from parts (STC T12 based), and it works fine for the most part, but from some odd reason, the display temperature keeps constantly jumping up and down! (The temperature itself however is very stable and accurate, according to my tip thermometer), so it's just a display issue. I've tried playing with the different settings (P00-P11) and made some research about what each of em does, but was unable to resolve it. If it helps, the main parts are these:https://www.banggood.com/STC-T12-Digital-Soldering-Iron-Station-Temperature-Controller-DIY-Kits-for-HAKKO-T12-Soldering-Iron-p-1146578.htmlhttps://www.banggood.com/4A-To-6A-24V-Switching-Power-Supply-Board-AC-DC-Power-Module-p-969204.htmlI've followed the instructions fully, and double checked that everything is wired correctly.I've also tried two different tips (just in case it was a faulty one) but that didn't help either.But yeah, so to sum it up, almost everything works properly (except for the display temperature erratically jumping up and down)Any ideas what the issue could be? I'm thinking it could be a faulty T12 controller, but any help would be appreciated.I'm hoping I could get this resolved without replacing it, but we shall see.

author: thm_w
author_rank: Super Contributor
timestamp: March 29, 2018, 11:09:31 pm
content: For some reason the thermocouple in the T12 tips takes time to "burn-in". So you will have to use it for maybe 1-2hr before it stabilizes.Its possible the official hakko tips are either pre burned in, or use a different manufacturing process.Seller explanation:QuoteMentioned here also:http://dangerousprototypes.com/forum/viewtopic.php?f=56&t=5264&start=450

author: RayRay
author_rank: Frequent Contributor
timestamp: March 30, 2018, 12:18:37 am
content: I appreciate your help thm_w, but that's definitely not the case (and for the record, it's not true either, as I've seen plenty of youtube videos with T12 diy's and this was never an issue, the temperature display remained stable in all cases). My controller is definitely faulty.It seems to be a grounding issue with it too. If I disconnect the grounding from the iron plug, the temperature display is stable, with it, it's erratic.Guess I'll have no choice but ordering a new one.

author: RayRay
author_rank: Frequent Contributor
timestamp: March 30, 2018, 01:23:08 am
content: Update: figured it out.Seems I've accidentally created a grounding loop.I've previously used some files to slightly expand the encoder hole (as it didn't align proper with the display)But in the process of doing this, I've removed some of the non-conductive paint in that area, which subjected it to a grounding issue.I've wrapped a small portion of the encoder with kapton tape, and it's all good now.
Need help to indentify this coax-connector... - Page 1
Forum section: electronics / repair

author: carl_lab
author_rank: Frequent Contributor
timestamp: January 26, 2018, 01:51:01 pm
content: Outer diameter of the male connector is 3.0mm:(sorry for poor image quality...)

author: David Hess
author_rank: Super Contributor
timestamp: January 26, 2018, 03:59:48 pm
content: They look like reversed sexPeltola connectorsbut they are not.I can see that that is a relatively modern design from the small outline surface mount. Is it audio or RF?

author: carl_lab
author_rank: Frequent Contributor
timestamp: February 07, 2018, 06:34:03 pm
content: It is RF, 10MHz.(sorry for my late reply...)

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: February 08, 2018, 01:29:54 am
content: From what I can discern on the photographs, I believe that there is no retaining mechanism. Is that correct?

author: carl_lab
author_rank: Frequent Contributor
timestamp: February 28, 2018, 07:23:45 pm
content: Quote from: Neomys Sapiens on February 08, 2018, 01:29:54 amYou are correct, it is just plugged together.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: February 28, 2018, 09:43:16 pm
content: Ok, from the picture I assume that the PCB-mounted part has a pin contact, but I cannot make it out really good! Does it intermate with some known series? It looks like the cable-mounted part goes INTO the pcb-mounted part completely. If the PCB jack had a female center contact, it could be a slide-on variant of MCX of 1.0/2.3. But the isolator on the cable-mounted 'plug' says female center contact.Most closely it resembles the inner parts of a SMB. Without the shell, so to say.Did you already try the Pasternack Identifier?What market segment is it?

author: carl_lab
author_rank: Frequent Contributor
timestamp: March 01, 2018, 02:55:58 am
content: Quote from: Neomys Sapiens on February 28, 2018, 09:43:16 pm

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: March 29, 2018, 02:30:00 am
content: Sorry, I'm officially giving up on this one. Did not find anything.
Wavetek 4808 Unstable DC Voltage - Page 1
Forum section: electronics / repair

author: Kenny Powers
author_rank: Contributor
timestamp: March 28, 2018, 05:14:41 pm
content: Hello,Posted this in the wrong settion earlier,I have a 4808 which is exhibiting intermittent misbehavior details below, has anyone else come across this and found a cure? I opened the unit and its spotless inside.For example, when set for 10VDC, it outputs 10V - but then the voltage (sometimes) slowly drift upwardsto, say, 12.6V.When this happens:-- the 1V and 100V ranges are seen to behave similarly- there is no output on the lower ranges- the 1000V range seems OK.The problem can be resolved, at least temporarily, by cycling the power or going up and down through the ranges a couple of times.(All other functions – ACV, Ohms etc. seem ok)

author: Samogon
author_rank: Frequent Contributor
timestamp: March 28, 2018, 09:57:10 pm
content: Looks like devider board has issues. But reference is ok

author: Kenny Powers
author_rank: Contributor
timestamp: March 29, 2018, 12:07:14 am
content: Any idea where this board is located or part number?

author: KhronX
author_rank: Frequent Contributor
timestamp: March 29, 2018, 12:19:03 am
content: Depending on the age of the unit, there's a chance some of the electrolytic caps might've started to kick the bucket.
Help to identify connector - Page 1
Forum section: electronics / repair

author: rodd
author_rank: Regular Contributor
timestamp: March 28, 2018, 04:33:08 pm
content: Hi,I bought a Global Specialty GS3600 logic analyzer at a very low price.The unit is like new but, unfortunately it came without the probes.I intend to build them myself, but I can’t figure out what is the female connector used in these ports.Any help would be appreciatedEnviado do meu iPhone usando Tapatalk

author: Kjelt
author_rank: Super Contributor
timestamp: March 28, 2018, 05:21:17 pm
content: Not 100% sure but they Look like a Mini D50 HPDB50 connector also used for scsi3I know these from NI testequipment (dac cards , dio etc).
Help SMD identification for newbie - Page 1
Forum section: electronics / repair

author: rednex
author_rank: Newbie
timestamp: March 28, 2018, 09:18:46 am
content: Hi all, Im a newbie, maybe someone can help to identify that SMDUnfortunatelly that smd has burnt, the picture was made from another SMDso I can not measure

author: KhronX
author_rank: Frequent Contributor
timestamp: March 28, 2018, 12:59:04 pm
content: The "U" prefix for component designators usually means it's some sort of integrated circuit (as opposed to a single or dual diode / transistor).I don't suppose you have any idea what the role of this is/was, in the circuit it's in?

author: rednex
author_rank: Newbie
timestamp: March 28, 2018, 01:40:12 pm
content: Thanks!the 6 pin smd is placed after 12V input connector and goes to AZ1117C low dropout three-terminal regulator

author: gamalot
author_rank: Super Contributor
timestamp: March 28, 2018, 01:51:24 pm
content: TPS562200http://www.ti.com/lit/ds/symlink/tps563200.pdf

author: rednex
author_rank: Newbie
timestamp: March 28, 2018, 02:17:47 pm
content: OMG! THANKS!
Keyboard Repair after spillage - Page 1
Forum section: electronics / repair

author: ZedRedLed
author_rank: Contributor
timestamp: March 27, 2018, 04:57:41 pm
content: Hi, I am trying to fix a Madcatz V7 Keyboard after a tea spillage and so far I was relatively successful.I replaced some diodes and redid some of the traces with conductive silver ink. After that it worked fine, however, after a couple days I started having strange crosstalk between some of the keys, with some not even working at all anymore.I thought this could be due to me having slightly bent the membrane or it shifting around so I tried securing it, but this only made a small difference. Also, it sometimes works for a couple seconds before the problems occur and briefly unplugging the keyboard seems to 'reset' the issue.Any idea what this could be?Thanks in advance!

author: Chriss
author_rank: Frequent Contributor
timestamp: March 27, 2018, 05:38:38 pm
content: Hi!From my experience that type of problem when some device is spilled with conducting fluid like in your case the water, that is in high percentage not repairable.Tha major problem is with the micro dirt in this case the water what is leftover on the whole pcb, board, unit whatever.Even of deep cleaning will not help.After a while there will build up some crossing area and that will brake traces, connect traces with each other where the corrosion act as a resistor....So. I realli wish you will come over your problem and I hope you will luckily repair your keyboard, but I don't have to much faith in...Try to clean the best you can.Tray to identify corrosion points, most of time between legs of ic's.Check for jumper corrosion between traces etc...My best wish!Sent from my GT-I8260 using Tapatalk

author: ZedRedLed
author_rank: Contributor
timestamp: March 27, 2018, 06:26:27 pm
content: Hi, thanks for the kind response!I'll give cleaning it another try, but I wonder, Is this something that I can measure with a multimeter? Because I tried to locate crossovers with the continuity tester and I couldn't find any, apart from actual traces on the membrane. This is why I thought that maybe the membrane is bent in a way that makes multiple buttons be pressed at the same timeAlso, I found another component that looks slightly corroded, but what is it? I don't have so much experience yet, I think it's a diode but I'm not familiar with what type looks like this. (Sorry for the bad picture quality)https://imgur.com/a/R5qMH

author: ZedRedLed
author_rank: Contributor
timestamp: March 28, 2018, 01:54:38 pm
content: Ok nevermind, I did some googling and I'm pretty sure it is a ferrite bead.How can I test if it is broken?On one side there was a little bit of corrosion, but does this mean the bead is damaged and could a damaged bead be causing my problems?It is located near the diodes coming from the top membrane traces
What materials are required to replace a DFN chip, with no visible pads? - Page 1
Forum section: electronics / repair

author: extraextra
author_rank: Newbie
timestamp: March 26, 2018, 09:25:10 pm
content: I have a board with a fried DFN chip and I'd like to replace it. It's a MOSFET in a DFN package and all of the pads are underneath it. This is the chip:http://www.ubiq-semi.com/en-article-upi-663-1875I've never done work on SMD components much less DFN and I'm not 100% sure where to start. I know I'll need a heat gun and tweezers for sure, and I saw somewhere that I can use foil to prevent me from blowing away the surrounding components, along with a note sheet recording what components were where so when I do accidentally blow them away I can put 'em back. What else do I need to have on hand? Flux, solder paste, some applicator(s), luck?I searched around and found a lot of information on what is required for general SMD rework -- what I saw (including the EEVBlog videos) made sense but it all relies on having access to the pins (or at least it seems to).Related: Is there a video by Dave about this specific subject? I couldn't find one with the term "DFN" in it. There's this video (QFN, close enough):but it demonstrates a way to install the chip with visible pads.

author: ataradov
author_rank: Super Contributor
timestamp: March 26, 2018, 09:32:22 pm
content: I do this kind of stuff by lightly pre-tinning both PCB pads and chip pads. Very lightly. Then put some flux and roughly position the chip. Apply heat. No need to cover anything, unless you have some plastic components nearby. If your air blows away surrounding components, you've got too much air, it will also blow away the chip you are trying to solder. Once solder is molten, poke the component slightly on the side, it should return to is right place with surface tension of the solder.Look at Louis Rossmann channel, he soldered plenty of chips with invisible pads.

author: extraextra
author_rank: Newbie
timestamp: March 26, 2018, 11:24:28 pm
content: Thank you, that makes sense. Solder paste and flux it is!

author: ataradov
author_rank: Super Contributor
timestamp: March 26, 2018, 11:30:54 pm
content: You don't even need solder paste. The combined amount of solder on the pads and the board after pre-tinning should be sufficient for reflow.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 26, 2018, 11:50:46 pm
content: for this puppy i use paste solder and hakko hot air station, the center pad is sometime used as dissipation surface

author: KhronX
author_rank: Frequent Contributor
timestamp: March 28, 2018, 01:10:02 pm
content: Check out some of Luis Rossmann's Macbook repairs on Youtube, plenty of QFN chip replacements to be seen (same style of package, but with pads on all four sides, hence the "Q" for quad, as opposed to "D" for dual).Hot air, flux and solder (no paste required)
Extron ADA 6 300 HV PSU Repair - Page 1
Forum section: electronics / repair

author: don.r
author_rank: Frequent Contributor
timestamp: March 28, 2018, 01:28:42 am
content: Just thought I would note a repair I did of an Extron ADA 6 300 HV Video Distribution Amplifier power supply. The PSU itself is made by Skynet and has an SK-8085 PWM controller. The common-mode choke shorted on the live side and let the magic smoke out. The corresponding leg of the following bridge rectifier was shorted. After replacing these and testing the major caps and the output diodes I was beginning to suspect the SK-8085 since it wasn't pulsing the switching MOSFET. As it turned out, the timing capacitor for this controller, a tiny 1uF electrolytic, was measuring 900pf and >100 ohms of ESR. Swapped that out and she is up and running.I know lots of people use the Extron ADA series as 10MHz distribution amps in their labs so I thought I would point out a rather obscure failure point.
Help identifying the manufacturer of a slide potentiometer? - Page 1
Forum section: electronics / repair

author: Metatronic_Mods
author_rank: Contributor
timestamp: March 09, 2018, 03:22:54 am
content: I'm just hoping someone will recognize the logo on this slide pot and can tell me who made it. Maybe that will help me locate one (1). It's a dual gang, 45mm long, 30mm travel, so far the only close match I've found had a minimum order quantity of 2000. And you know ...repair.

author: amspire
author_rank: Super Contributor
timestamp: March 09, 2018, 04:05:33 am
content: I do not know the brand, but ALPS slider pots are usually relatively easy to get and they look very similar:http://www.alps.com/prod/info/E/HTML/Potentiometer/SlidePotentiometers/RS__1/RS30112AC00J.htmlSeem to be available from Mouser and a few other suppliers.

author: Rog520
author_rank: Regular Contributor
timestamp: March 09, 2018, 04:19:28 pm
content: Looks like a company called "Favor Union" out of China. If you can identify the particular model number you might be able to request a sample from them. The standard route would be to go through the equipment manufacturer or their authorized parts distributor and order a replacement part.http://www.polyshine.cn/

author: Testtech
author_rank: Regular Contributor
timestamp: March 09, 2018, 10:19:46 pm
content: Futaba perhaps?

author: Metatronic_Mods
author_rank: Contributor
timestamp: March 27, 2018, 03:12:11 pm
content: Quote from: Rog520 on March 09, 2018, 04:19:28 pmYeah, if the company wasn't some fly-by-night shakedown run by what I can only assume are two guys under thirty, a dog and two cats. Or maybe it's one guy over 30 and a factory in China which he visited once during the late nineties and now receives a check from every so often just as a token gesture for all the "loaned" IP.Thanks for the idea, though, I'm not sure if they came up when last I looked. I'll give them a try here in a bit.
HP8751a repair - Page 1
Forum section: electronics / repair

author: medical-nerd
author_rank: Regular Contributor
timestamp: March 30, 2018, 07:57:38 pm
content: HiyaI have a HP8751a network analyzer in very good condition. On first power up it booted successfully and ran for about 15 mins then turned off. No escape of smoke.The power supply has 2 diagnostic LEDS on the back - the bias present LED is on as should be but the shutdown LED is flashing with a short click somewhere in the internals.Taking off the lower cover, what appears to be a large regulator board has a few LEDs flashing with the power shutdown LED - no external evidence of damage.I want to remove the power supply to check it but can see no way how without dismantling the entire machine.Any advice please, or a service manual? I have searched but only found a maintenance and user manual so far.Cheers

author: TAMHAN
author_rank: Frequent Contributor
timestamp: March 31, 2018, 03:42:40 pm
content: Hello,I took apart a 8753C recently. All of the covers need to go, and then the back can be "flipped out". I can send you pics if you want...Tam

author: medical-nerd
author_rank: Regular Contributor
timestamp: April 01, 2018, 02:55:13 pm
content: HiyaThanks - I'll attack the beastie again after the weekend.Cheers

author: TAMHAN
author_rank: Frequent Contributor
timestamp: April 02, 2018, 01:58:48 am
content: Email me at tamhan aht tamoggemon roundthing com, so that I can forward the pics. Posting them here is such a hassle...
Lacrosse BC900 Battery Charger -- Bad display after opening it? - Page 1
Forum section: electronics / repair

author: hpmaxim
author_rank: Regular Contributor
timestamp: March 26, 2018, 03:47:27 am
content: I have a pretty old BC900, whose buttons didn't work well. So based on advice I've seen on the net, I decided to open it and clean it. I use a combo of acetone and ESD mat cleaner (don't ask). When I opened it and removed the board the display came out with the board, and was stuck to the board. I accidentally knocked it off the board. Also, fluid went everywhere, including onto the display (I think it was all on the exterior but its hard to tell). I dried everything off with a hot air gun (low heat, high flow)... and put it back together again.I just put the display back in the case and then put the board in and screwed it down. When I did, the charger seemed to be totally dead. I took it apart, cleaned and dried it again, and re-assembled, a couple times, and invariably it'd either appear completely dead OR the display would act funky (i.e. very low contrast, and most of the segments were turned on). However, it was distinctive enough to lead me to believe the board is actually working. I.e. when you first power it on only the segments in the 4th battery position turn on (where it displays the firmware number) and then that goes off, and all of them come on (like if it were displaying "null") on all batteries. The board is no longer attached to the display -- as in when I remove the board now the display doesn't come with it, it just sits in its cavity in the case.Any ideas?

author: hpmaxim
author_rank: Regular Contributor
timestamp: March 26, 2018, 07:51:42 am
content: Well, this is weird. I just tried plugging it in again after letting it sit for a couple hours. The display is working much better. If I hold it at an angle, I can CLEARLY read it, as in it looks basically perfect. Unfortunately, when looking at it head on, it still looks quite faded. Maybe something was still wet? Interestingly, the fade is absolutely consistent across the entire display.

author: metrologist
author_rank: Super Contributor
timestamp: March 26, 2018, 07:36:30 pm
content: it was probably still damp, or residue. I have the same charger and it's been working fine for many years. Are there any tips that have come up for these? I think I recall them charging a little hot.

author: edavid
author_rank: Super Contributor
timestamp: March 26, 2018, 09:33:46 pm
content: It uses a zebra strip between the board and the display. It has to be dry, properly aligned, and firmly in contact on both sides.
Fluke 80K-6 HV Probe  I need new replacement tip  - Page 1
Forum section: electronics / repair

author: Johnny10
author_rank: Frequent Contributor
timestamp: March 26, 2018, 12:49:35 pm
content: Fluke 80K-6 HV ProbeI picked up this unit with no tip.Wondering if anyone knows a source for replacement tip?Thanks

author: HighVoltage
author_rank: Super Contributor
timestamp: March 26, 2018, 01:43:14 pm
content: Probably difficult to source.I made one myself on a lathe, out of brass.If you don't have a lathe, have a machine shop make one for you in a few min.

author: EldenChang
author_rank: Newbie
timestamp: March 26, 2018, 08:01:20 pm
content: You can also use a 4mm screw in banana plug instead of the original tip.
Identifying MSOP-10 ACQ/BEJ  - Page 1
Forum section: electronics / repair

author: engavi
author_rank: Newbie
timestamp: March 26, 2018, 05:58:52 pm
content: Hi,I'm trying to identify an smd IC, MSOP-10 encapsulated, which is serigraphed with the following: ACQ (in the first line) and BEJ (in the second line).The V in (pins 4 andare shorted to ground (pins 2 and 7) . I suppose it's a double linear voltage regulator, but as much as I look in s-manual, or Turuta smd codes, I do not find any that resembles it.Can someone give me an idea what is, to replace it?Thanks in advance!
Burned motor connector on a electric motorcycle - Page 1
Forum section: electronics / repair

author: Urs42
author_rank: Unknown
timestamp: March 26, 2018, 02:30:54 pm
content: HiI found the reason why my electric scooter is complaining about motor sensor errors the connector between the bldc controller and motor got a little bit too hot. I've replaced the motor and controller with spares. I'm not sure why this happened, it is possible that some moisture got in to the connector i will use some contact grease on the spares.I'm now looking for ideas how to repair both connectors. I can't cut the wires, they are already too shortShould i order some replacement connectors and try to replace them without shortening the wires?The motor is rated for 4kW