hybridfree/eevblog-posts huggingface dataset:
Lamp Part Missing - Page 1
Forum section: electronics / repair

author: Tratatat
author_rank: Newbie
timestamp: March 25, 2024, 04:46:11 pm
content: What part would I need to make this a functioning lamp?

author: themadhippy
author_rank: Super Contributor
timestamp: March 25, 2024, 05:16:32 pm
content: looks like the outer skirt is missing,best just buy a complete lamp holder
lappy backlight inverter fail. - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: August 26, 2021, 08:26:03 pm
content: just thought i would ask this,a few weeks ago my lappy screen went black ie no backlight,i changed the inverter and it was ok for about 3 seconds then a small noise from the inverter board and another black screen!,luckily i had another spare screen and inverter so fitted them and all is fine,just a question tho,could a fauly cold cathode backlight kill two inverters or was it coincidence?
lappy noisy psu - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: December 15, 2019, 09:27:21 pm
content: hi all,ive a dell inspiron lappy,it works fine exept the power adapter wipes out most of 80+40m ham bands out with hash at s9,any idea how i can cure this?,ive tried ferrites on the cable but made zero differance,cheers m3vuv.

author: Kleinstein
author_rank: Super Contributor
timestamp: December 15, 2019, 10:08:26 pm
content: The best chance is probably to get a new supply. Ferrite beads can help a little, but it is better to have a SMPS that does not produce the EMI from the start. There is chance there is either a defect causing the trouble or the given model was a poor design to start with.

author: TheMG
author_rank: Frequent Contributor
timestamp: December 16, 2019, 12:34:43 am
content: Is it the original OEM power supply, or a replacement? Normally the OEM power supplies are pretty good noise wise but I've encountered more than a few aftermarket replacement power supplies that have basically no EMI filtering and are noisy as heck.Also, is the laptop in question connected to your radio equipment in any way? With certain antenna types, especially if it's not well matched (at the feedpoint) and/or does not have a good RF ground, it's easy to get conducted RFI into the radio. How close is your antenna (and its feedpoint) to the laptop?
lappy screen fault. - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: August 26, 2021, 09:16:36 am
content: Hi all,long story ,a few weeks ago i sold a laptop to a friend cheap,they payed half the moneys for it then said they would pay the remainder on payday,the lappy was spoton when they took it,when it came to finish paying for it they said the screen was iffy and didnt want it,i refunded them and took it back,i would like to know if the issue is down to abuse or if its the video card or screen pannel,what do folks think?,its a dell inspiron 1720 with a 2.5gig cpu and a seperate video card.

author: wraper
author_rank: Unknown
timestamp: August 26, 2021, 09:32:29 am
content: LCD mechanical damage. Your friend is a scumbag. Somebody probably sat on it or something like that.

author: CJay
author_rank: Super Contributor
timestamp: August 26, 2021, 09:34:29 am
content: Physically damaged screen.

author: Specmaster
author_rank: Super Contributor
timestamp: August 26, 2021, 10:06:22 am
content: Looks to me as they closed the lid down with some wedged between the screen and keyboard.

author: Ian.M
author_rank: Super Contributor
timestamp: August 26, 2021, 11:03:32 am
content: With it powered off and oblique lighting from the side, look at the surface of the screen in the damaged area. You'll probably see indentations from whatever object it was closed on that did the damage.

author: m3vuv
author_rank: Super Contributor
timestamp: August 26, 2021, 09:01:57 pm
content: just seen this,it looks like b.s to me,what do you guys think.also there is no sign what so ever of damage to the screen,it looks like new.

author: wraper
author_rank: Unknown
timestamp: August 26, 2021, 09:08:20 pm
content: Quote from: m3vuv on August 26, 2021, 09:01:57 pmProbably it could work since that was a small damage without the glass braking, and it wasn't fixed entirely. When I inspected black spots like on your display under microscope, I've seen circular cracks in the glass somewhere in internal layer. If you try this, black spots most likely will become even larger.

author: m3vuv
author_rank: Super Contributor
timestamp: August 26, 2021, 09:14:50 pm
content: sorry it was the wrong vid.

author: aqibi2000
author_rank: Regular Contributor
timestamp: August 26, 2021, 11:24:54 pm
content: Your mate is not your mate, he’s a f*$~$¥\er

author: m3vuv
author_rank: Super Contributor
timestamp: August 27, 2021, 08:19:06 am
content: yup it looks like i got shaffted.
lappy screen replacment confusion - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: February 24, 2022, 08:58:35 pm
content: Hi all,i have 2x dell inspiron 1720 lappys with dead ccfl backlights,i found this on fleabay,can it be right? or just a missleading con listing?,to me it reads as a led backlit lcd screen?.:https://www.ebay.co.uk/itm/362527723495,surley you cant replace a ccfl backlit screen with an led backlit one without mods to the lappy,ie inverter etc?

author: abdulbadii
author_rank: Frequent Contributor
timestamp: February 25, 2022, 06:32:50 am
content: Too few now care CCFL as its advantage just a more even light, or more even over a lager size LCD.. withdownside- CCFL backlight requires a higher voltage- CCFL backlight requires an inverter- Contain mercury, as many countries limit or bans CCFL- Shorter life time then LED. An estimated 21000 to 30000 hours

author: Whales
author_rank: Super Contributor
timestamp: February 25, 2022, 10:26:06 am
content: Some laptops came with a choice of screens, perhaps this (or an equivalent) was an option? The inverters were often on separate boards, ie removable.(Definitely don't use the inverter on the LED backlight!)Best I can suggest is contacting the seller and asking.

author: m3vuv
author_rank: Super Contributor
timestamp: February 25, 2022, 06:02:23 pm
content: Well,i have messaged the seller twice,but no reply,did you look at the listing?,i know the pro's and con's of ccfl v's led but need to know if the screen listerd is going to be compatible with my inspiron pp22x,as far as i know there was never a pp22x produced with an led backlit screen.

author: Whales
author_rank: Super Contributor
timestamp: February 25, 2022, 09:21:46 pm
content: I have no way of telling just looking at the listing, sorry.* Pinout and protocol for the main cable needs to be the same* Motherboard needs to support a non-inverter power supply (both in hardware connectors & firmware)With more modern laptops and screens you have similar issues with the eDP connectors and pinouts. Some are the same, some are not. Different motherboards/graphics support different numbers of eDP lanes, for some screens you need more.

author: flolic
author_rank: Frequent Contributor
timestamp: February 25, 2022, 09:32:36 pm
content: That screen will not fit.You need something like this:https://www.laptopscreen.com/English/model/Dell/INSPIRON%201720/And that's next to impossible to find...
Laptop Ac power Adapter Repair !! - Page 1
Forum section: electronics / repair

author: battery13v
author_rank: Contributor
timestamp: July 09, 2019, 08:29:34 am
content: hey everyone i have a problem with this laptop ac power adapter, its original problem was that when there is too much load on it it will cycle on and off ... like from 19V to 10V to 19V to 10V every 1 secondso i open it up and i did not found anything visually .. i tested the main capacitor (100uf) and it measured 60uf so i changed it ... and while testing i accidentally made a short between the resistors that are attached between the main capacitor and the groundafter that it stopped working .. after some test i found that the mosfet was dead and i changed also the pwm ic and still not working ... after that i found this two shorted transistors that i dont know what is their role so if someone could explain to me what are they doing and how could i replace them cause they dont have any indications ...thx everyonei attached a visual explanation ...

author: shakalnokturn
author_rank: Super Contributor
timestamp: July 09, 2019, 08:58:49 am
content: They'll be a push-pull stage (one NPN, one PNP) between the PWM output and the MOSFET.Their aim is to improve switching times providing more current to the capacitive MOS gate.

author: battery13v
author_rank: Contributor
timestamp: July 09, 2019, 04:14:20 pm
content: Quote from: shakalnokturn on July 09, 2019, 08:58:49 amThanks bro ... so will the Q1 be npn or pnp?, same thing for the Q2 will it be the pnp or npn one ??

author: shakalnokturn
author_rank: Super Contributor
timestamp: July 09, 2019, 06:00:11 pm
content: I read Q2, Q3.Q2 would be the NPN, that should answer the other question.
laptop Acer swift SF314-41 Repair - Page 1
Forum section: electronics / repair

author: OvO
author_rank: Newbie
timestamp: April 26, 2024, 03:07:45 am
content: my laptop has a weird problem. it has a power on issue.Once the laptop has been powered on, it can restart/ wake just fine on battery power or Adapter, ONLY If i have not closed the LID/LCD even once.If i have closed the LID /LCD (even momentarily). it will not power-on/ wake-up on battery power no matter the battery percentage.but once i open the LID and connect it to the adapter (even momentarily) it will wake up gain and I wont experience any issues till i close the LCD.i do not know where to look for repair.help

author: m k
author_rank: Super Contributor
timestamp: May 01, 2024, 04:48:26 pm
content: The close screen function is powered from two sides, battery and charger, now battery side is not working.Probably so that some signal is pulled down and should be popping back up when the lid opens.Can also be just a setup.When lid is closed the machine goes to too deep sleep.Or setting is so that stay off when power goes out and it's not functioning as expected.
Laptop CMOS battery Could an ML1220 cell be it? - Page 1
Forum section: electronics / repair

author: Zeyneb
author_rank: Regular Contributor
timestamp: April 07, 2022, 11:13:46 am
content: Hi,With some high effort I was able to disassemble the Acer TravelMate 8000 laptop to the level that I could get to an ML1220 cell. But as I don't have a repair manual for this laptop I'm not sure if this ML1220 is actually the CMOS battery. It was located near the main battery connector.I hope if I replace this ML1220 cell it does solve it by remembering BIOS info. Could there be any possibility there would be another battery cell on this motherboard?

author: DK ekectro
author_rank: Contributor
timestamp: April 07, 2022, 12:41:36 pm
content: Your CMOS battery looks like big button style watch battery.There is only one CMOS battery on the motherboard.
Laptop faulty screen diagnosis? - Page 1
Forum section: electronics / repair

author: The Soulman
author_rank: Super Contributor
timestamp: July 03, 2020, 08:32:29 pm
content: The wive's laptop (hp elitebook 8460p) developed a failure in the displayed image.I've re-seated the screen cable but no change, also wiggling the cable doesn't change things.At the moment I want to know what the cause could be:1) something on the motherboard (i.e. laptop is toast)2) the screen cable and/or screen itself (something that could be replaced)3) something I didn't think of.Anyone guesses based on the attached pic?

author: flolic
author_rank: Frequent Contributor
timestamp: July 03, 2020, 08:40:09 pm
content: That's problem with LCD panel.

author: Rasz
author_rank: Super Contributor
timestamp: July 03, 2020, 10:49:06 pm
content: you can exclude GPU if the screen has same lines in different graphic modes9 year old laptop, one of the worst screens on the market when introduced, you finally have an excuse to upgrade
Laptop HP elitbook 480 problem - Page 1
Forum section: electronics / repair

author: Atifmo
author_rank: Newbie
timestamp: February 19, 2022, 08:01:11 am
content: Hello to allI have an HP elitebook 480 laptop when I turned off my pc after a few seconds the fan starts with noise and the 02 lights on the right light up. Can you help me plz.

author: abdulbadii
author_rank: Frequent Contributor
timestamp: February 19, 2022, 11:45:02 am
content: just open cover to clean up the parts inside, google how to for this type

author: coromonadalix
author_rank: Super Contributor
timestamp: February 19, 2022, 11:59:48 am
content: I had an older elite book in the past, theses errors may be due to dust / crust or a failing fan, the board is detecting the fan rotation speed and doesnt like it ...In mine i changed the fan ...In some case you can clean it and lube it, sometimes you can lift the fan sticker and push some oil in it, i use teflon based oil, i can extend the fan life that way
Laptop Keyboard Repair - Page 1
Forum section: electronics / repair

author: OpenCircuit
author_rank: Regular Contributor
timestamp: February 19, 2020, 11:59:46 pm
content: The W, S X keys and the LED back lights are not illuminating on this keyboard. Probing the obvious voltage supply for the back lights (A4NA14) it appears A4NA 14 is not passing 5V through to the top-right pin of A4NA 14 when the laptop is powered on. I dont know if the A4NA 14 is faulty or if it is not receiving power on command from another source on the mainboard. When the laptop is powered on current is 280ma across the 5v pin and the top-right pin of A4NA 14 and the back lights illuminate when checked with DMM. Problem likely with A4NA 14 or something else? 12V goes to 0v when the laptop is powered on. Can't seem to find specs on A4NA 14EDIT: Found a KB9028Q C which appears to be a keyboard controller.

author: OpenCircuit
author_rank: Regular Contributor
timestamp: February 20, 2020, 08:17:22 pm
content: It appears Q8 controls the gate on Q7 and Q7 being controlled by the "KB_LED_EN" signal? I can increase voltage to back lights positive by simply touching the neg and pos terminals on the probes and voltage will rise to to almost 2 volts to the backligths.What to replace first?
laptop Lcd help needed Hpfolio 1029 - Page 1
Forum section: electronics / repair

author: dave_j_fan
author_rank: Regular Contributor
timestamp: June 24, 2022, 08:48:09 am
content: Are thse lcd compatiblehp folio 13 and hp probook 5310because i am getting 5310lcd=====i am in indiaso we cant buy via ebay.com because shipping is high.

author: wraper
author_rank: Unknown
timestamp: June 24, 2022, 09:10:52 am
content: You should buy by LCD panel model, not laptop model. Not to say the laptop base model may come in variants with a different LCD which are not compatible. Websites like Panelook list specifications of the vast majority of panels, so you can compare if important specs match if you buy a different LCD model as replacement.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: June 24, 2022, 04:19:24 pm
content: thank ulcd is F2133wh4can anyone helpme with few other compatible lcd numbers

author: wraper
author_rank: Unknown
timestamp: June 24, 2022, 06:25:19 pm
content: LP133WH4-TJA1 should do the job, apparently it's the only compatible type. This is a very specific LCD and there are no tons of replacements as usually.
Laptop mother manufacturers and part numbers. - Page 1
Forum section: electronics / repair

author: keerthi123
author_rank: Contributor
timestamp: November 05, 2020, 07:40:00 pm
content: Dear all,As we know, for each motherboard schematic there is a part number. I would like to know whether there are more than one computer models are made of same motherboard schematic. Also I am curious whether there is a relationship between similarly of mother board and their naming convention. Also an example Quanta Project ZHS and Quanta Project ZHT (imaginary) are mostly similar.If there is such a relationship we can find the next closest schematic when original is not available. Appreciate the opinions of experts here.

author: Rasz
author_rank: Super Contributor
timestamp: November 06, 2020, 11:49:10 am
content: all depends on manufacturerMSI used to sell only slightly modified designs simultaneously under own brand and oem. They would cut&paste a slot, sound controller, or a southbridge like for example MSI K7D Master (MS-6501) and Tyan Thunder K7 (MS-6502).

author: coromonadalix
author_rank: Super Contributor
timestamp: November 06, 2020, 06:18:31 pm
content: For an Alienware laptop i have, there is 3 different mother boards, i was lucky to have the latest one with raid sata in it, the others ones where in raid "ide" ports ...You have the same case but different hardware
Laptop repair 20v rail intermittently getting pulled down to 5v - Page 1
Forum section: electronics / repair

author: Rik_Koningen
author_rank: Newbie
timestamp: November 26, 2024, 06:14:38 pm
content: I'm slowly learning more advanced repair, it's already my job but I'm becoming more advanced as I go. Right now I'm stumped by one laptop at work. The 20v rail is getting pulled down to 5 volt at fairly regular intervals. Too quick for a multimeter to show but the scope shows it just fine. Once every 2 or so seconds it drops for about 150 micro seconds. Laptop acts like it gets no power in general the whole time. No voltages present outside of that 20v. And as it's on longer it starts dropping deeper and deeper down to 3v after half an hour. Also no components are getting detectably hot in the process at all.Tested with mobo fully removed from the chassis and with everything unplugged. Same result. No "regular" shorts are present on the board at all. At this point this is a worthless laptop I'm mostly looking at to learn so I've as much time as needed to figure it out (while no actual priority work exists, or in my breaks anyway). What could be causing this? I've got a feeling it's my battery management chip since voltage exist before it but not after. But I mainly want to know why this happened and how on earth we get at that weird intermittent not quite short circuit that pulls my 20v down. I kind of don't want to just replace the chip before knowing why or at least having an idea so if anyone knows I'd greatly appreciate any insight. Multiple other power sources also tried to same results.
Laptop repairs in Melbourne Carlton area - Page 1
Forum section: electronics / repair

author: Baron Gray
author_rank: Newbie
timestamp: August 13, 2020, 04:06:26 am
content: HiMy brother lives in Carlton South, Melbourne and just let some of the special smoke escape from his HP M7 laptop, whilst attempting an SSD upgrade. I can't help him as I am in Sydney. Would anyone know of a good laptop hardware repairer in Carlton or surrounds? I believe there are restrictions on how far he can travel due to the lockdowns. He rang some of the so called PC repair places and they just went down the "Antivirus or Malware" issue path even after we explained the smoke issue. Any help would be greatly appreciated as the PC is his only connection to the outside world.

author: Baron Gray
author_rank: Newbie
timestamp: August 13, 2020, 05:48:11 am
content: I found AMT electronics in Elizabeth street so will give them a go.
laptops with pristine design intent - Page 1
Forum section: electronics / repair

author: LootMaster
author_rank: Regular Contributor
timestamp: November 07, 2020, 12:18:43 pm
content: I know its hard to identify the "good ones out there" since we are so early into their warranty... Have the management strategies changed for some companies?Here are some "good ones"... Me I always prefer laptop over desktop now... You can take it anywhere, if there a fitre you can save your posession.https://www.eevblog.com/forum/repair/pre-emptive-capacitor-change-on-beloved-laptop/msg3284742/#msg3284742
LASER DIODE ID - Page 1
Forum section: electronics / repair

author: tekguy
author_rank: Contributor
timestamp: September 29, 2022, 02:00:05 am
content: tHIS DIODE IS DEAD,ITS FROM A CD PLAYER,CAN ANYONE ID IT PLEASE SO I CAN GET A REPLACEMENT?,THANKS IN ADVANCE.

author: tekguy
author_rank: Contributor
timestamp: September 29, 2022, 02:01:18 am
content: Sorry didnt mean to shout,caps lock key was toggled!.

author: Haenk
author_rank: Super Contributor
timestamp: September 29, 2022, 07:32:39 am
content: These lasers are all special parts and were not publically available. There is zero chance of finding one, unless it's a spare part (for service) or pulled (removed from another machine).So essentially your only option is to pull one out of a working machine (which might be otherwise damaged or in bad shape - unfortunately, the diodes were the most common part to fail...)

author: tekguy
author_rank: Contributor
timestamp: September 29, 2022, 07:43:50 am
content: Bummer,i thought that was the case,its a candidate for landfill then i guess!.

author: Haenk
author_rank: Super Contributor
timestamp: September 29, 2022, 10:28:50 am
content: Sidenote: it does look extremely corroded - since the pickup mechanics itself is quite fragile, I honestly doubt that a new laser would be of much help anyway - plus it would need adjustment
Laser repair schmatic New Wave Research - Page 1
Forum section: electronics / repair

author: jdolecki
author_rank: Contributor
timestamp: February 07, 2023, 03:30:30 pm
content: Need to find schematic for New Wave Research Pegasus PIV laser .Or any type of documentation.Since the company is long gone and the internet is not producing any results I’m hoping someone here might know something or someone.Thanks John.

author: MathWizard
author_rank: Super Contributor
timestamp: February 10, 2023, 01:01:37 pm
content: Besides universities, how many companies need lasers, besides laser pointers ?What's wrong with the laser?

author: jdolecki
author_rank: Contributor
timestamp: February 11, 2023, 01:31:14 am
content: It was acquired my local college.Haven’t been used in years.And they want to get it running to do experiments.New was 100k even flea bay ones are 10 k now.Powers on but I can’t make the temp fault go away. At first I thought it was a thermzister but that working.All Inputs put go into a Zylog fpga.I currently looking at the chiller and seeing if that’s isSending an error message but it’s a serial communication.So any inflow would be helpful just thought someone on her might know something.

author: MathWizard
author_rank: Super Contributor
timestamp: February 11, 2023, 08:16:09 pm
content: Is that water cooling ? Yeah I'm no expert on repair.I would pray that the problem is some component on the outside, and not that FPGA.

author: jdolecki
author_rank: Contributor
timestamp: February 11, 2023, 08:25:15 pm
content: Yes the power of the laser requires its own chiller.I working on the serial interface now to see if it’s sending a temp fault.The one picture shows what I believe is a thermzister. I can put my meter on it and see the resistance rising as the water is chilling.It’s in the little blue plug with the two white wires coming from it.

author: josephgc
author_rank: Newbie
timestamp: May 06, 2025, 07:11:30 pm
content: I am also working on a Pegasus-PIV laser and wondering if you ever found any schematics or solved your issue.I am not using the original chiller and am having difficulties getting the flow interlock switch to go off.
Laser resonates with ceiling speaker to create a horrible ?ground loop? - Page 1
Forum section: electronics / repair

author: DonKu
author_rank: Regular Contributor
timestamp: October 30, 2022, 02:50:40 pm
content: Received a phone call from a client in regards to a new medical laser device. Whenever the laser is activated it causes a sympathetic loud hum in only one of the Valcom ceiling speakers - located relatively far away in the waiting room. Speakers closer to the laser show no symptoms.Haven't gone on-site yet. AFAIR, a sheilded audio cable feeds the speakers, and a LM386 drives them. The built-in Valcom LM386 amp uses a couple of exposed spade terminators, spaced about an inch apart, to connect to the audio line.Is it possible for the terminators to act as an antenna? Or, does this indicate a broken/incorrect ground?Thanks in Advance.OK. It turns out the Valcom system uses cheap twisted pair and not the shielded audio line imagined in my mind. So, the most likely culprit is a twisted pair paralleled with an electrical line in the ceiling. The Valcom speaker will be disconnected to solve the problem.
Laser Soldering   OH&S  issues - Page 1
Forum section: electronics / repair

author: JoeyG
author_rank: Regular Contributor
timestamp: April 30, 2022, 11:50:24 am
content: Anyone see OH&S issues with this toolhttps://youtu.be/71gS_omFVo4

author: BreakingOhmsLaw
author_rank: Frequent Contributor
timestamp: April 30, 2022, 02:13:30 pm
content: Yikes! That looks like high powered UV.Also, the "beautful girl" marketing is super creepy.Well, not quite as creepy as the JLCPCB Naomi Wu video for their 3D-print service.

author: tooki
author_rank: Super Contributor
timestamp: April 30, 2022, 02:58:41 pm
content: Quote from: BreakingOhmsLaw on April 30, 2022, 02:13:30 pmInfrared, not UV.

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 30, 2022, 07:46:58 pm
content: Quote from: BreakingOhmsLaw on April 30, 2022, 02:13:30 pmNaomi Wu is pretty good about working safely. The most cringeworthy use of models in tech advertising are the Power Jack inverter ads.
LB1668 2 phase motor controller - Page 1
Forum section: electronics / repair

author: okw
author_rank: Frequent Contributor
timestamp: December 14, 2022, 07:07:34 pm
content: Hello,I have a fan with a faulty(?) controller. It is a YHWM-9733 DC18V 340mA fan. Sometimes it turns on and runs fine (inrush current 270mA, running at 195mA), but most times it's dead and draws only 8mA. If I manually spin it while energised, it kicks in and runs normal. The controller has a minimal circuit with LB1668, two resistors, one MLCC and one electrolytic (2.2uF) cap, a diode and some tiny 4 pin chip (designated H in the datasheet and connected to the amplifier in+ in- gnd and vcc), and an unpopulated inductor.Any insight of what could be faulty? I measured the diode OK, the electrolytic is about 2.2uF and 8 ohms ESR (tried with two others at about 1 ohms, no solution).My thoughts are the LB1668 or "H" (which I have no clue what is)

author: fzabkar
author_rank: Super Contributor
timestamp: December 17, 2022, 08:35:50 pm
content: Datasheet:https://media.digikey.com/pdf/Data%20Sheets/ON%20Semiconductor%20PDFs/LB1668_M_May2013.pdf"H" would be a Hall Effect sensor. If you disconnect the power to the fan, and then rotate the fan by hand, you should see IN+ and IN- change state.

author: okw
author_rank: Frequent Contributor
timestamp: December 17, 2022, 09:19:47 pm
content: Thanks. What could it indicate when the motor randomly doesn't start by itself, but needs a lilttle help? When it needs help, it's almost drawing no current, not does it "vibrate" like a normal motor struggling to start.

author: fzabkar
author_rank: Super Contributor
timestamp: December 17, 2022, 10:43:26 pm
content: I would check the supply voltage and motor bearing. Compare the resistances of the two phases.Monitor the Hall effect inputs and phase outputs with a scope while the fan is running.Measure the C and RD pins when the fan is stopped.
LC574AM - Page 1
Forum section: electronics / repair

author: Nature
author_rank: Newbie
timestamp: November 29, 2021, 03:13:50 am
content: I have the Croy LC574AM oscilloscope Power on display CL_match_gains_or_offsets:4,8 Offse and CH4 does not test the waveformWhat is the problem?" alt="" class="bbc_img" />

author: Stray Electron
author_rank: Super Contributor
timestamp: November 30, 2021, 12:45:30 am
content: I have a LC 534 that has the same problem. it's COMMON in the leCroy LC series. if you look closely at the ones on E-Greed MOST of them have it. That's why the sellers try to sell them as "untested". LOL! In addition to the error message, the display will usually go haywire. I haven't tried to fix mine but there's some messages floating around that say that the problem is a failing PLL IC in the scope. Somewhere I have the PN of the IC but I can't find it at the moment. But when I looked it up a few years ago the part was available from Digikey. I've been meaning to order some but never did. You should go over to the LeCroy group, the problem has been discussed there and they give the part number.The problem on mine originally only occurred after the scope was on for a few hours but gradually the problem occurred sooner and sooner until it only ran error free for a few seconds. Blowing a LOT of air on the scope made no difference.

author: Nature
author_rank: Newbie
timestamp: November 30, 2021, 04:10:28 am
content: Thank you Stray ElectronAccording to your suggestion I will consult the relevant personnel
LCD Controller Board problem - Page 1
Forum section: electronics / repair

author: sduy
author_rank: Newbie
timestamp: June 22, 2023, 03:30:35 am
content: I have a LCD controller board and when I connected it to a power source it showed red light (laptop screen not connected yet). Still showed red light when I connect the screen.I noticed the screen displayed very weak light when connected.The weird thing is when I use a HDMI cable to connect the board to my pc it showed green light but the laptop screen still black.Is this a power source problem?

author: ArdWar
author_rank: Frequent Contributor
timestamp: June 22, 2023, 03:58:33 am
content: It might be silly, but have you connected the backlight power supply?

author: sduy
author_rank: Newbie
timestamp: June 22, 2023, 04:08:29 am
content: What is backlightMy screen look like this

author: m k
author_rank: Super Contributor
timestamp: June 22, 2023, 08:55:37 am
content: WXGA TFT-LCD with WLED backlight.https://datasheetspdf.com/datasheet/N140BGE-EB3.html

author: sduy
author_rank: Newbie
timestamp: June 22, 2023, 09:18:58 am
content: Do I need to connect something into this?

author: coromonadalix
author_rank: Super Contributor
timestamp: June 22, 2023, 10:31:47 am
content: you bought a interface without knowing how it work ?is it configured for the lcd size ?? on some models you need to flash the right lcd specs .....

author: sduy
author_rank: Newbie
timestamp: June 23, 2023, 04:30:45 am
content: I changed to a different power source and the screen was just bright like thisMy screen is 1366x768 HD TFT 30 pin edp
LCD drum module repair ideas - Page 1
Forum section: electronics / repair

author: mikee30
author_rank: Newbie
timestamp: October 28, 2020, 02:17:20 am
content: Hi,I am working on repairing the LCD screen in a Roland drum module. The original issue was that the bottom half of the screen had sections fading out over time, which I was able to correct by dismantling the drum kit and cleaning all connectors to the LCD as well as from the LCD to the motherboard. I did this using contact cleaner and had to use some compressed air in sections that I noticed had small pieces of dust stuck on the connectors.Now, I am trying to repair a second issue which is the appearence of bubbles in the display which is amplifed when power is connected. The "bubbles" look better/worse depending on the angle I look at the screen. Any ideas on how I can manipulate the bubbles to either all go in one section, join together or somehow eliminate them from the LCD? I am OK with dismantling the module again and removing the LCD. Buying a replacement LCD does not seem to be an option as it is no longer available.Here are some photos showing the LCD on and off as well as a piece of the component when it was removed:https://ibb.co/K62y2fFhttps://ibb.co/hgYvqLjhttps://ibb.co/g3ZnW3Yhttps://ibb.co/6NrDfM2Any ideas would be greatly appreciated!

author: Haenk
author_rank: Super Contributor
timestamp: October 28, 2020, 05:59:05 am
content: Glued on polarizer foil delaminating?(Just a wild guess...)Edit: Looks like this is not an unknown issue to some LCDs, so yep, probably the polarizer unsticking itself.)
LCD faulty line does not go all the way across. - Page 1
Forum section: electronics / repair

author: gkmaia
author_rank: Frequent Contributor
timestamp: July 11, 2020, 11:46:42 am
content: My Macintosh Portable has developed a line on it's LCD.The line goes all the way but the last 5 left pixels. There is no sign of where failure starts.I also can't say it is bad contact from driver as the line does not go all the way.Anyone with more experience on LCD could help me understand what type of fault is that?

author: Haenk
author_rank: Super Contributor
timestamp: July 11, 2020, 11:56:03 am
content: I'd put my money on defective memory...

author: TheMG
author_rank: Frequent Contributor
timestamp: July 11, 2020, 03:01:31 pm
content: I have no specific experience with the Macintosh Portable, but generally speaking such a problem could be due to one of many different types of faults:-internal fault in the LCD panel itself-fault in a driver IC (on back of LCD panel PCB)-fault in the computer's video memoryThe easiest way of ruling out the later, if you can get another LCD module to swap in. That will tell you if the fault is in the LCD display module or the computer (video memory).Since the line does not go all the way across the LCD panel a bad connection to the LCD panel glass edge can be ruled out.

author: gkmaia
author_rank: Frequent Contributor
timestamp: July 12, 2020, 04:15:54 am
content: Looking at the microscope and mapping the pixels it gives me words from 15601 to 15679 are faulty.I will replace the memory and see what happens.

author: gkmaia
author_rank: Frequent Contributor
timestamp: July 20, 2020, 08:17:30 am
content: Memory has been replaced. Line is still there.I got to think about something else....
LCD flex repair, ACF bonding as home, any hints? - Page 1
Forum section: electronics / repair

author: jchw4
author_rank: Regular Contributor
timestamp: August 28, 2022, 12:13:58 pm
content: I got a nice micrometer but LCD was ripped off.Googling suggests that this kind of repair is nowadays done with ACF bonding and there are plenty of videos advertising different automatic repair machines.But in this case the whole LCD is like 4cm x 2cm, and the bonding area is hardly more than ~12mm.Is it reparable at home at this scale? Did anybody try that? I guess it should not be very difficult.Where to buy ACF adhesive at small scale?In Youtube videos they use "ACF cleaning liquid". What is that?

author: prolux
author_rank: Newbie
timestamp: August 31, 2022, 12:02:18 am
content: Try powering the unit up and press the flex onto the glass and see how many digits appear, If you get a good display, just heat something flat up to around 120 Celsius and remelt the bonding adhesive.
LCD for uniden  RM 960 part number - Page 1
Forum section: electronics / repair

author: targit
author_rank: Regular Contributor
timestamp: August 28, 2023, 06:40:26 am
content: Hi, I was given a Uniden UH9060 with an RM 960 mic which has a smashed LCD , I managed to find the LCD part number under a piece of aluminium foil (only purpose seemed to be covering up the part number) but drawing a blank on who makes it, google search and usual suspects gives no useful results. Maybe this number will be useful to someone or if you recognise who makes it?Thanks.

author: Swake
author_rank: Frequent Contributor
timestamp: August 28, 2023, 12:41:32 pm
content: That is likely a custom LCD for them.
LCD I.D. - Page 1
Forum section: electronics / repair

author: Audiorepair
author_rank: Frequent Contributor
timestamp: December 17, 2021, 01:29:11 pm
content: Hi,can anyone ID this colour LCD? Not really my field of expertise.It's from a Roland FA06 keyboard.https://instrumentalparts.com/led-lcd-display-screen-roland-fa-08-07-06-5100033810/

author: Audiorepair
author_rank: Frequent Contributor
timestamp: December 18, 2021, 11:10:15 pm
content: Oh well, looks like the owner is f***ed then.Well done Roland.

author: amyk
author_rank: Super Contributor
timestamp: December 18, 2021, 11:20:10 pm
content: Find the resolution and controller, it's likely there are compatible replacements. For the latter you will need a basic logic analyser.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 18, 2021, 11:23:18 pm
content: https://www.ebay.com/itm/154587978324https://www.ebay.com/itm/402532248152
LCD ITO pads - conductive ink repair? - Page 1
Forum section: electronics / repair

author: noerby
author_rank: Newbie
timestamp: April 18, 2022, 02:38:31 pm
content: Hello EEVblog community, first time posting here!Some of the ITO pads have worn out on my mid-80's segmented LCD display. See picture below. I don't know if they did so upon removal of the old broken heat seal cable, or during operation somehow.I hoped it would work after all, so I tried to install a new heat seal cable, but several segments were not working, and others had poor contrast.Short of having a replica display made, the display is irreplaceable. My thought so far is attempting to paint the pads using silver ink, and hoping that enough ITO trace remains to successfully bridge with the ink.I'm concerned however with the adhesion onto the glass, which conductive ink to use, the difficulty of accurately applying the ink on the 1.27mm pitch pads, and potentially causing more damage to the ITO traces.Has anyone ever attempted a repair of worn/broken ITO traces or have any advice on this?Thank you all for a wonderful forum!Worn ITO pads:[ Specified attachment is not available ]
LCD module backlight identification - Page 1
Forum section: electronics / repair

author: khaahk
author_rank: Contributor
timestamp: March 24, 2022, 01:14:12 pm
content: What type of backlight is this? Where to buy replacement?

author: TheMG
author_rank: Frequent Contributor
timestamp: March 24, 2022, 01:19:00 pm
content: Electroluminescent (EL).Pretty much obsolete nowadays due to LED backlights.Keep in mind these EL backlights run from high voltage AC, so a LED retrofit would require removal/bypassing of the high voltage EL driver circuit.

author: khaahk
author_rank: Contributor
timestamp: March 24, 2022, 01:37:50 pm
content: Thanks for the information!

author: Audiorepair
author_rank: Frequent Contributor
timestamp: March 24, 2022, 01:38:30 pm
content: There are companies throughout the world that still make these things.You don't reveal where you live.https://www.backlight4you.com/EL-Panels/EL-Replacements:::46_130.html?language=en

author: George Edmonds
author_rank: Frequent Contributor
timestamp: March 24, 2022, 02:59:15 pm
content: HiThese are not high voltage devices and they have a known life time mesured in hoursLook on eBay thre are listings for the supply of themG Edmonds

author: khaahk
author_rank: Contributor
timestamp: March 24, 2022, 09:11:52 pm
content: Quote from: Audiorepair on March 24, 2022, 01:38:30 pmSeems like a good source, thank you! (EU is fine)Quote from: George Edmonds on March 24, 2022, 02:59:15 pmBy "these are not high voltage devices" you are referring to the EL-Replacements website linked above or i did not understand you correctly?They seem to me like a direct replacement.Thanks

author: Audiorepair
author_rank: Frequent Contributor
timestamp: March 24, 2022, 09:21:40 pm
content: By "these are not high voltage devices" you are referring to the EL-Replacements website linked above or i did not understand you correctly?They seem to me like a direct replacement.ThanksThere are similar looking LED backlights from the same company.https://www.backlight4you.com/LED-Backlights/LED-Retro-Backlights:::135_137.html
LCD monitor motherboard not powering up - Page 1
Forum section: electronics / repair

author: Electro Man Bot
author_rank: Newbie
timestamp: August 15, 2024, 10:08:37 am
content: Hi,I have a faulty motherboard controlling G150XG01 LCD monitor. Picture attached of motherboard. I have being searching online for a schematic of the board, none of the codes are giving any results when searching. Is it possible to get schematics for this? Is it possible to repair these surface mount pcb's, what are the common faults?Thanks in advance for any help/advise.

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 15, 2024, 10:38:56 am
content: Consider that the schematic is difficult to obtain.It could be that the backlight is just not working, etc.Is it not even recognized in computer?Above CN7 in the image you can see F1 “Fuse”. I think it is a fuse for the backlight. Have you checked continuity?check that the regulator is outputting voltage normally.The probability of damage to the LCD controller is small.I believe this display is at least 15 years old, as it has DVI but does not appear to have HDMI.the capacitors and other components in the power supply will be damaged over time.

author: Electro Man Bot
author_rank: Newbie
timestamp: August 15, 2024, 11:09:09 am
content: Fuse is ok, continuity checked. Which component is the voltage regulator and what would the expected value be?I'm not sure if the LCD screen itself is working, it is not recognized connected to a laptop and there is a LED on the board (listed as LED3 on upper right side of image), this is not lighting when 12v PSU is connected to board.

author: tunk
author_rank: Super Contributor
timestamp: August 15, 2024, 05:14:43 pm
content: Are you sure the PSU is OK?

author: Electro Man Bot
author_rank: Newbie
timestamp: August 18, 2024, 11:16:21 pm
content: Yes, PSU is ok. I can measure 12v at psu connector on board.
LCD monitor motion traing ghosting problem. - Page 1
Forum section: electronics / repair

author: sdancer75
author_rank: Frequent Contributor
timestamp: September 14, 2019, 11:14:53 am
content: The motion trail ghosting problem, is a monitor or video card problem?If its a monitor problem what kind of part is responsible for this?Regards,

author: shakalnokturn
author_rank: Super Contributor
timestamp: September 14, 2019, 01:04:29 pm
content: Not sure in your specific case, usually this is the sort of symptom you'll see with a bad shielding.

author: Dacke
author_rank: Regular Contributor
timestamp: September 14, 2019, 03:03:50 pm
content: Agreeing with the shielding issue shak said. Try moving the monitor/cable around and see if anything changes. If you're using VGA, try replacing the cable.

author: Rasz
author_rank: Super Contributor
timestamp: September 14, 2019, 03:57:52 pm
content: vga cable?

author: sdancer75
author_rank: Frequent Contributor
timestamp: September 14, 2019, 04:46:41 pm
content: This is a computer in my work..... So, as soon as I return to work, I will test the cable I will let you know.Best Regards,
LCD monochrome screen faded - Page 1
Forum section: electronics / repair

author: Mugiwara303
author_rank: Contributor
timestamp: February 22, 2024, 07:48:22 pm
content: Hi guys, anyone have an idea what causes the LCD screen of a car radio to fade and become illisible especially when exposed to sun and heat and can it be fixed without replacing the lcd screen, see the attachment and thank you

author: jpanhalt
author_rank: Super Contributor
timestamp: February 22, 2024, 07:58:02 pm
content: Bright sunlight is the worst enemy:https://lg-mri.com/sunlight-and-solar-clearing/Heat doesn't help either.
LCD no image after firmware flash (Philips Avent SCD603) - Page 1
Forum section: electronics / repair

author: daskorn
author_rank: Newbie
timestamp: February 17, 2023, 09:01:35 pm
content: Hi eevblog community,a while back I bough a Philips Avent SCD603 baby phone. It was listed as defect and the description said that the camera and the receiver unit are not able to connect anymore. I took the risk and tried to repair it. I failed. I couldn't find / measure anything broken on either of the devices (camera/receiver). I came to the conclusion that the seller was not honest and maybe those two units never knew each other. So I bought a second set, an almost working one which I managed to repair.Now having a good and a bad unit a revisited the first one. I dumped the Winbond Flash chips of the working camera and receiver and flashed it on the bad ones. The camera now worked fine, I was able to view the image of the bad camera on the good receiver. Also the bad receiver was able to connect to the good camera and of cause now also to the bad one.But here comes the problem - which absolutely makes no sense to me. The LCD of the bad one stopped working. Just a black (sometimes white) screen with backlight on. I knew that it connected to the camera because sound was working fine. But the LCD showed now image. No boot screen, nothing. So i switched over the LCDs and the bad unit was now fully working. The good unit with the bad screen didn't work. Flashing back the bad firmware the bad LCD was working again.Both LCDs share the same part number: LM1223A01-1D.What on earth is going on here? Any ideas?I'm not familiar with interfacing LCD screens but I wouldn't expect that there is something like a serial number check implemented to avoid screen replacement.In case you need more information about the exact chips used on the board. Just let me now.Thanks in advancedaskorn
LCD Problem - Page 1
Forum section: electronics / repair

author: GuitarDude
author_rank: Newbie
timestamp: August 06, 2022, 09:16:57 pm
content: Hail all.See the LCD (with elastomeric connectors) of the transparent device on this video:https://youtu.be/KXjBXFq_sTQDoes anyone know the name of this sort of "bleeding" problem, its cause and its solution?Much grateful for all your help.

author: GuitarDude
author_rank: Newbie
timestamp: August 10, 2022, 03:08:17 pm
content: No one knows then?

author: jpanhalt
author_rank: Super Contributor
timestamp: August 10, 2022, 04:26:13 pm
content: Watched most of the video. It's a bit hard to see exactly the problem. Some of what's shown looks like the contrast is set too high. Some may be failure to erase properly. When I erase an LCD, I print every pixel with a 0. There are possibly other causes.Can you post a picture of your LCD to clarify exactly what the problem is?

author: GuitarDude
author_rank: Newbie
timestamp: August 10, 2022, 10:46:39 pm
content: Thank you for answering.There is also this video (none of these videos are mine):https://youtu.be/Dd9XnJT687sBut that first video already has an immediate comparison. In its first 15 seconds the problem can be seen. The brown device has the pixels right, as they should be, with clear figures on screen. The transparent device has all its pixel figures with shadows (half lit pixels?). Its owner speaks about this fault at 1m13s...and says that the LCD was changed, but it did not correct it... Could this then by some fault on the circuit board? Any guess where?

author: jpanhalt
author_rank: Super Contributor
timestamp: August 10, 2022, 11:13:08 pm
content: A pixel on an LCD screen stays on until it is turned off. Turning it off requires sufficient voltage. Turning it on is the same. Contrast as well as the Ve (negative voltage) supply and perhaps time (i.e., interface speed) controls both. I have never had the problem you see; however, I have had the problem of insufficient "boost voltage" result in dim images. Changing my "boost" fixed it. That was a firmware change. I don't have a clue about what you can control with your device. Nevertheless, I suspect it is firmware and not a defect in your screen.EDIT: You might find this video by fearless Dave helpful:https://www.eevblog.com/forum/blog/eevblog-1045-how-to-drive-an-lcd/msg1371450/#msg1371450
LCD Problem - STM32F4 Discovery Kit for STM32F469 MCU - Page 1
Forum section: electronics / repair

author: girishv
author_rank: Regular Contributor
timestamp: February 14, 2023, 02:50:50 am
content: I am having problems with STM32F469I discovery kit LCD. Recently, I lifted my laptop forgetting the discovery kit is still connected and may have damaged the LCD screen.I am seeing these lines on startup of board.The board seems to be working fine as I can still program the board using builtin ST-LINK.Any suggestions to salvage the LCD?

author: thm_w
author_rank: Super Contributor
timestamp: February 15, 2023, 11:51:24 pm
content: It looks like it has a ribbon cable going to the back of the PCB, and a ZIF socket.Inspect and reseat that connection.

author: girishv
author_rank: Regular Contributor
timestamp: February 17, 2023, 05:30:02 pm
content: Quote from: thm_w on February 15, 2023, 11:51:24 pmI disconnected the ribbon cable and connected it back. No luck.Thanks for the suggestion.