hybridfree/eevblog-posts huggingface dataset:
Fluke 77 problem - all characters on LCD stay lit - Page 1
Forum section: electronics / repair

author: Tallie
author_rank: Regular Contributor
timestamp: December 28, 2015, 05:41:12 am
content: I know of the notorious faded LCD issue... what could cause all the characters to stay lit?

author: retiredcaps
author_rank: Super Contributor
timestamp: December 28, 2015, 06:02:23 am
content: Quote from: Tallie on December 28, 2015, 05:41:12 am1) It sounds like it is not coming out of self test mode. The service manual (page 3-10) has 5 tests.2) Clear focused pictures of your pcb board (both sides) with the lcd removed will also help.3) If you haven't tried a fresh 9V battery, do so. The 77 has an outstanding 2000 hour battery life, but when it gets low, it might cause funny readings and/or non start behaviour?4) Excavatoree, a member here, has seen poor soldering on U1 causing all sorts of problems. You may want to examine U1 under magnification.

author: Cubdriver
author_rank: Unknown
timestamp: December 28, 2015, 10:07:12 pm
content: I'd start with a new battery and go from there.-Pat

author: Tallie
author_rank: Regular Contributor
timestamp: December 28, 2015, 10:14:57 pm
content: Thanks for the advice. I've downloaded the service manual and will try all the things you've said. I'll report back... eventually...

author: Excavatoree
author_rank: Frequent Contributor
timestamp: December 30, 2015, 06:39:49 pm
content: You might want to gently press on the SMD IC near the bottom of the PCB. Some of these had poor soldering on this IC, and I've fixed a few by re-soldering.Sometimes, that IC gets damaged and all you get is the self test, but first perform the tests that retiredcaps mentioned.

author: Tallie
author_rank: Regular Contributor
timestamp: January 02, 2016, 08:50:39 pm
content: TP1 = 4.55 - 4.58VTP2 = 3.0V avg, 34.1Hz @ 50% dutyC5, 6, 7, and 8 are goodR15 to R16 reads .858V reference, not 1.00VY1 reads correct frequencyDisplay voltage is good... reads 1.6VI'd could probe the pins if I knew how to count them... pin 1 isn't marked on the either chip; U1 or U2... on U1, checking for 1V reference, if I start at the bottom left corner and count counterclockwise to 14 - counting every pin, I get nothing on the scope. If I count to 14, counting only the pins that are soldered to the board, I get 3.18V on the scope.Something interesting happened while I was trying to probe the pins on U1... when I flipped the meter back over, it was working... all ranges were working. I don't know what I did... so I turn it off, reassemble everything, turn it back on, and now it's back to not leaving the self test screen... any help is welcome!

author: ZeroTolerance
author_rank: Contributor
timestamp: January 02, 2016, 09:12:08 pm
content: Sounds like a bad solder joint

author: Tallie
author_rank: Regular Contributor
timestamp: January 02, 2016, 11:06:37 pm
content: Well, it's working consistently now. No clue how I fixed it... I did power it on slowly a couple of times(turned the knob slowly)... I noticed it would pass self check when I did that, now I can turn it on normally and it will operate. A switch problem? I've got a can of DeOxit on the way...
Help sourcing vintage PTC/Positor replacement for degaussing coil - Page 1
Forum section: electronics / repair

author: lazarusr
author_rank: Regular Contributor
timestamp: December 24, 2015, 09:48:11 am
content: I have a vintage CRT monitor with a failed three pin positor/PTC for the degaussing coil. The part number of the positor (taken from the service manual) is 263100P2332T333. But I cannot find anything about this part number online.I attach some pictures of the part. The markings on the part are “T 333”.The monitor is a Microvitec Cub 1451MS monitor which was commonly used with BBC Computers in schools in the UK. It hails from around 1984.It has a 14 inch colour Mitsubishi CRT (part number M34JBF02X01) with what appears to be an entirely unremarkable degaussing coil.The CRT is somewhat different to that used in domestic TVs in that it has a higher resolution mask suitable for computer displays of 505 x 585.I would be grateful for any assistance in selecting a suitable replacement. I am not fussed in finding anything that is original or of a suitable vintage. I just want one that works and ideally has a similar ‘footprint’ so as to easily fit on the PCB.Any suggestions on a suitable replacement or where I could enquire would be greatly appreciated.

author: Ian.M
author_rank: Super Contributor
timestamp: December 24, 2015, 10:29:08 am
content: I'd start by tracing the circuit to determine if the heating element for it is series or shunt. Apparently some 3 pin posistors use a NTC heating element in series with the PSU's main power feed that also provides inrush protection, and others have a shunt PTC heating element across the mains supply. Once you've confirmed the pinout, you might be able to cross-reference it to something else that's still available, maybe using the tables in this Vishay datasheet:http://pdf.datasheetcatalog.com/datasheet/vishay/23226629.pdfWorst case, if its got the usual shunt heating element, odds are most 3 pin posistors from similar screen size tube TVs would be compatible - but double check the pinout.

author: Deathwish
author_rank: Unknown
timestamp: December 24, 2015, 11:26:43 am
content: It's a thermistorhttp://www.cjemicros.co.uk/micros/individual/newprodpages/prodinfo.php?prodcode=MVT-PH9344http://stardot.org.uk/mirrors/www.bbcdocs.com/filebase/hardware/Microvitec%20Service%20Manual%20Series%203%20Colour%20Display%20Monitors.pdf

author: lazarusr
author_rank: Regular Contributor
timestamp: December 24, 2015, 11:48:06 am
content: Thanks. That's the part I am looking for. Indeed, the info in the link has allowed me to find suitable replacement for much cheaper than CJE are selling it. It turns out that it is just a standard generic positor/PTC.

author: lazarusr
author_rank: Regular Contributor
timestamp: January 02, 2016, 12:40:49 pm
content: Positor replaced. Monitor working. Thanks for the help.
Tektronix 468 Position and Beam Find Problem - Page 1
Forum section: electronics / repair

author: cliffordjsmith
author_rank: Newbie
timestamp: December 29, 2015, 12:05:22 am
content: My Tektronix 468 Position adjustment knobs don't move either trace below the center of the display, and the Beam Find isn't visible even when I push it after I have a trace displayed. I've got the service manuals, but would appreciate any advice, especially on whether I should start with the power supply or the vertical preamplifier board.

author: tautech
author_rank: Super Contributor
timestamp: December 29, 2015, 12:18:28 am
content: Quote from: cliffordjsmith on December 29, 2015, 12:05:22 amWelcome to the forum.Always start with PSU checks.If all seems well it could be an imbalance in the vertical system.In the Repair board you'll find a good pdf for troubleshooting Tek scopes:https://www.eevblog.com/forum/repair/repair-documents-and-links-sticky-me-please-mods/Check the schematic for DC voltage values, these help immensely in finding an area in the circuitry that is faulty. Study the Service manual for instruction as to how the scope should be set for DC voltages to be relevant.

author: Addicted2AnalogTek
author_rank: Frequent Contributor
timestamp: January 01, 2016, 06:22:45 pm
content: If you're 468 has socketed transistors, your best bet is going to be to pull the vertical amp board and check all the semiconductors on it. It sounds like there is a major offset in the voltages between the vertical deflection plates.It would help if you put some signals into the inputs and gathered some more info. Dig into the Volume 1 manual and run the vertical section performance check, subbing equipment as you need to. If frequency isn't stated, such as for the amplitude calibrator equipment checks, the frequency is 1Khz.
Tube ID and test question - Page 1
Forum section: electronics / repair

author: Planobilly
author_rank: Regular Contributor
timestamp: December 22, 2015, 01:13:52 am
content: Hi guys,I have a Fender late 60's silver face twin reverb amp. Three of the pre amp tubes are marked RCA 7522 in red and near the top on the other side of the tube they are marked USA 7025.I can not find a setting sheet for this tube on my TV-10 Navy tube tester.The data sheet says they are just like a 12AX7 but used where low noise and hum is a requirement.Can I use the same settings to test as a 12AX7??Thanks,Billy

author: med6753
author_rank: Super Contributor
timestamp: December 22, 2015, 01:39:01 am
content: 7025 = 12AX7. Use the settings for 12AX7.

author: Planobilly
author_rank: Regular Contributor
timestamp: December 22, 2015, 02:19:35 am
content: Thanks,I assumed as much.Billy

author: gadget73
author_rank: Regular Contributor
timestamp: December 24, 2015, 08:57:53 pm
content: The 7025 is an industrial low noise version of the 12ax7. Basically its a premium part. Absolutely interchangeable with a 12ax7 though.

author: TimFox
author_rank: Super Contributor
timestamp: December 31, 2015, 09:46:55 pm
content: You may find that the TV-10 and similar military tube testers use too much grid AC drive for a high-mu low-current tube such as the 12AX7 and its variations.Can you set up a test circuit with another socket? Measuring the plate current vs. plate voltage at a fixed grid voltage (as on the data sheet characteristic curves) is tedious, but trustworthy.
SMPS dc-dc 12V-atx - Page 1
Forum section: electronics / repair

author: raresvintea
author_rank: Contributor
timestamp: January 02, 2016, 10:13:23 pm
content: Hello i have this dc dc 12V-atx power, and i've burned it by puting 30V instead of 12 on the imput. I was finding a 4435 Mosfet shorted and now the 5V standby voltage is ok. But when i want to put the green to the ground no voltages. i've removed some caps to test the with the ESR meter. Sorry for the messy weldings. I want to repair to find out how it works!The big IC is ISL 6225CAZ and the IC from the left is 1507 0537 AL. I've tested the other mosfets and it seemed fine.Any oppions are ok and any obersevations are great!

author: SeanB
author_rank: Super Contributor
timestamp: January 02, 2016, 10:22:51 pm
content: Buy a new one, as it is very likely the main converters are both blown. If you applied 30V to the mainboard of a PC as well that will definitely be fried as well, along with the CPU and probably the memory, along with any boards plugged in as well.

author: raresvintea
author_rank: Contributor
timestamp: January 02, 2016, 10:30:07 pm
content: The board was an older one and it died. I wanted to repair and to learn. It's not the firts one and i hope not the last one
replacement GPIB standoffs - Page 1
Forum section: electronics / repair

author: alanambrose
author_rank: Frequent Contributor
timestamp: December 30, 2015, 11:56:23 am
content: Hi,Anyone any idea where to get replacement GPIB standoffs i.e. the male/female ones that screw into the socket and then the GPIB plug screws into them. Yes, I broke one - like serial sockets, undoing the plug often nets you the standoff out of the socket as well, and I was attempting to put the standoff back fairly tight. eBay and Aliexpress are not much help with this one. They are apparently an:M3.5 Socket with a 6-32 Screw (!)I can't think why we don't use that idea anymore. The ones I'm looking for are:M3.5 x 0.6 thread / 15mm total length / with 5mm head plus a 3mm shoulder plus a 7mm threadAny thoughts or clues welcome? I'm in the UK if it makes a difference.Regards, Alan

author: dom0
author_rank: Super Contributor
timestamp: December 30, 2015, 02:06:41 pm
content: I made a few GPIB connectors from the normal centronics-like connector. I just used M3 bolts and got a M3.5 thread cutter from eBay and cut the M3.5 thread over the existing M3 thread. The bolts were 10 mm length afair and needed some filing down to allow the connector to fully fit in. Because of how the normal thread cutters work it isn't possible to tighten the screw all the way in, but it's deep enough.

author: alanambrose
author_rank: Frequent Contributor
timestamp: December 30, 2015, 10:36:37 pm
content: Thanks that's a pretty workable idea - and I think there are some thread cutters that go all the way to the bottomChecking I see that M3.5 is a 0.6mm thread and M3 a 0.5 but I guess it's not critical.A.
Looking for schematic of Synology DS409+ main board - Page 1
Forum section: electronics / repair

author: Robartes_m
author_rank: Contributor
timestamp: December 29, 2015, 12:20:20 pm
content: Hi,this is a bit of a long shot, but one never knows. I have a broken Synology DS409+ NAS at home and I want to have a go at repairing it. Does anyone happen to have the schematic of the main board of this NAS? The internet is silent about this, and the machine is long out of production and out of support.Thanks!

author: Monkeh
author_rank: Super Contributor
timestamp: December 29, 2015, 01:27:59 pm
content: More than a little unlikely.If Synology won't give you one (they won't.), I doubt you'll ever find one.

author: HighVoltage
author_rank: Super Contributor
timestamp: December 29, 2015, 02:07:46 pm
content: I tried to get some infos from Synology before and they are very secretive about it. This will not be available anywhere.

author: Robartes_m
author_rank: Contributor
timestamp: December 29, 2015, 03:52:24 pm
content: Quote from: HighVoltage on December 29, 2015, 02:07:46 pmYeah - I figured as much. Oh well - I'll give it a shot at finding out what's wrong with it. It won't boot, doesn't even draw enough power to start its power supply (it's a switcher that goes in no-load shutdown). Powering it from a lab supply results in a clicking sound from the on board buzzer (which normally beeps on startup). I'm guessing it's a power supply issue somewhere.

author: jc101
author_rank: Frequent Contributor
timestamp: December 29, 2015, 08:15:06 pm
content: I have a DS412+ currently not doing anything, I could take some readings from the PSU if it helps, I think they all use the same external brick.

author: Robartes_m
author_rank: Contributor
timestamp: December 29, 2015, 09:04:10 pm
content: Quote from: jc101 on December 29, 2015, 08:15:06 pmThanks, but I think I was unclear above. The power brick is fine (once you put some load on it) - the issue is that the main board is not drawing that load, probably because one of the buck converters on it is broken.Thanks again!
Looking for McMurdo Aust connectors - Page 1
Forum section: electronics / repair

author: Kryten 2X4B
author_rank: Contributor
timestamp: December 29, 2015, 10:25:19 pm
content: I'm restoring an AWA BAC-1 Consolette, which is a broadcast studio console from 1960's / 70's. This console uses a number of 10 way male and femaleMcMurdo connectors, see below. Back in the day McMurdo, which is now ITW McMurdo, made components here in Australia. I don't have a part numberfor these parts but from the markings on the male connector these were made in Australia. So if anyone has some or these please contact me.

author: SL4P
author_rank: Super Contributor
timestamp: December 29, 2015, 11:02:23 pm
content: Sorry - no help, but I hadn't heard that name (McMurdo) for many years...I remember them well - and surprised if they are still around!They had an interesting range of heavy duty connectors.

author: Kryten 2X4B
author_rank: Contributor
timestamp: December 30, 2015, 06:15:08 am
content: I think this particular connector pair were only made in Australia, so if there are any to be found they are only going to be NOS or used.ITW McMurdo still make connectors and the Red Range has a similar shaped pin to that used on the male connector.
Help needed to identify IC - Page 1
Forum section: electronics / repair

author: Gixy
author_rank: Regular Contributor
timestamp: December 28, 2015, 10:52:39 am
content: Hi guys,I'm trying to re-engineer a DC motor variator. The two power MOSFET are driven by two ICs marked GY9D, with SOT23-5 packages. I can't find references of this circuit, which is probably also a MOSFET. Anyone knows that circuit?Thanks in advance.

author: mikerj
author_rank: Super Contributor
timestamp: December 28, 2015, 11:10:37 am
content: The code is not familiar, but there are many MOSFET drivers in SOT23-5 packages so it seems likely that it's one of those. Trace out the circuit, if the SOT23 has a separate supply and ground pin, then it's going to be a driver rather than a single discrete MOSFET.

author: rich
author_rank: Frequent Contributor
timestamp: December 28, 2015, 03:22:21 pm
content: perhaps MCP1401T-E/OT ?

author: Gixy
author_rank: Regular Contributor
timestamp: December 28, 2015, 03:38:24 pm
content: @richYes sir! That's it. Thank you.https://www.eevblog.com/forum/Smileys/default/clap.gif@mikerjThank you mike, I'm going to trace out the circuit in order to remake a PCB for a little serial.
Fluke 115 - Page 1
Forum section: electronics / repair

author: Gangway
author_rank: Contributor
timestamp: December 16, 2015, 05:46:47 am
content: Trying to open my Fluke 115 to repair LCD, any clues how Range selector dial comes off?Have removed all screws on PCB, just having problem removing selector, even with a spudger.Don't want to break anything.Cheers

author: retiredcaps
author_rank: Super Contributor
timestamp: December 16, 2015, 07:29:15 am
content: Maybe Martin's teardown of the Fluke 115 below will give you some clues?

author: Gangway
author_rank: Contributor
timestamp: December 16, 2015, 07:49:38 am
content: Brilliant! Easy when you know how. Thanks retiredcaps, glad i didnt continue, the wrong way.Great vid. Will continue repairs tomorrow at work.

author: retiredcaps
author_rank: Super Contributor
timestamp: December 16, 2015, 07:52:52 am
content: What is wrong with your lcd? Cracked from being dropped?

author: Gangway
author_rank: Contributor
timestamp: December 16, 2015, 08:17:02 am
content: Find out tomorrow, customer scrapped this meter, no display & chip of glass taped on front of meter?

author: Gangway
author_rank: Contributor
timestamp: December 17, 2015, 04:21:58 am
content: Bad news, LCD screen broken across top right corner, lost about four lines, so no display of data. Backlight ok. Cost of replacement LCD, if available maybe not cost effective for this low end Fluke dmm.

author: Muttley Snickers
author_rank: Unknown
timestamp: December 17, 2015, 05:04:19 am
content: I did a search but could not find many options in regards to cheap replacements, you may need to contact Fluke or one of the repair centers such as the one linked below, the EBay listing indicates that it would cost about half the meters value if shipped from the US. Fluke Part Number : 2509955.Fluke Centreshttp://www.fluke.com/fluke/auen/support/service/EBay Listinghttp://www.ebay.com.au/itm/U-S-A-FLUKE-113-114-115-116-117-LCD-Display-Meter-Display-Fluke-LCD-/261735249407Parts List Picture

author: Gangway
author_rank: Contributor
timestamp: December 17, 2015, 07:56:23 am
content: Thanks MS, thats exactly the same options i looked at today. Have checked all input protection parts & PCB,So meter should be good to go. Think this will be a new year project.

author: Robomeds
author_rank: Frequent Contributor
timestamp: December 18, 2015, 07:39:26 pm
content: You might find either a broken Fluke 11x meter or even a working 113. The 113's sometimes don't sell for much. Of course a 115 can also be had for $70-80 if you are patient.

author: Gangway
author_rank: Contributor
timestamp: December 24, 2015, 05:40:39 am
content: Contacted Fluke service agent Sydney, new LCD ordered & received next day.excellent service.Early christmas for me!

author: retiredcaps
author_rank: Super Contributor
timestamp: December 24, 2015, 05:50:58 am
content: Quote from: Gangway on December 24, 2015, 05:40:39 amHow much was the new LCD if you don't mind sharing that info?
Lampton FC2 Fan controller - reversed polarity damage - Page 1
Forum section: electronics / repair

author: poxxxy
author_rank: Newbie
timestamp: December 28, 2015, 03:46:40 am
content: Hi guys,I was gifted this PWM fan controller by a friend as he thought I may be able to get it working. The damage sustained had taken out two of the channels. I made some repairs to traces with jumper wires and replaced 2 diodes. Now I have the 2 channels that were dead working, but they only run on full power and the pot has no impact.I tried switching the transistor from another good channel, and also a pot over from another good channel but no luck. I just through a 1n4007 diode on the board as its all I had lying around. The channels are meant to be upto 45w per channel.Any help on where to look next would be appreciated.I will get some pics up tomorrow first thing.
(SOLVED)1968 Fender Twin Reverb Optoisolator / Vibrato Issue - Page 1
Forum section: electronics / repair

author: Planobilly
author_rank: Regular Contributor
timestamp: December 24, 2015, 04:25:59 am
content: Hi guys,Any way to test the optoisolator in a Silver Face Twin?I just rebuilt the amp and everything is working well except the tremolo.BTW, the Tube Amp Doctor TAD 7025 WA and the F&T caps were great with zero noise. Never had a NOS RCA 7025 but they can't be much better.Cheers,Update: New optoisolator...replaced plate cap on v5...now back to normalBilly

author: gadget73
author_rank: Regular Contributor
timestamp: December 24, 2015, 05:48:53 am
content: Whats the optoisolator in use? I've got very little experience with them, but I think some guitar amps ran the same type as my Sound Tech 1700A uses. In the ST, its more of a light controlled variable resistor. If you can turn up the spec sheet, it should have a chart that cross-references input voltage to output resistance.http://www.muzique.com/news/clm6000-replacement/Not sure if thats what yours runs, but it seems to have been a common one for that job. Its what the ST uses as well. Basically by that sheet, you should see about 500K ohms across it with no input to the LED, and 500 with the LED being fed 2 volts at something under 40ma.
What part is this - Page 1
Forum section: electronics / repair

author: Derresh
author_rank: Contributor
timestamp: December 21, 2015, 12:43:50 pm
content: Hi everyoneSo I am trying to repair a ipeps box (its a nice KVMoverIP system), someone decided to put a bit to much power on the input and charred one part. Lucky I got a second one so I decided to check the markings on the part that got reduced to charcoal. And here is where i ran in to a wallhttps://www.dropbox.com/s/z5sinid0t6ytcns/2015-12-21%2013.34.27.jpg?dl=0I need to replace the part that has that is between C150 and C149, Yet the markings on it make it hard to find, what is this ? ID86F did not give me anything in google. Any clue ? Its possibly a voltage regulator as it overheated when someone attached 12V instead of 6V on the input powerCheersDerresh

author: Brumby
author_rank: Unknown
timestamp: December 21, 2015, 04:09:04 pm
content: Hmmm... I couldn't find anything either - but I'm not an SMD guru.

author: pmichel
author_rank: Contributor
timestamp: December 21, 2015, 04:23:16 pm
content: It could possibly be a 1D86F.On this pagehttp://www.s-manuals.com/smd/1dthere is a part 1D=*** in a SOT-25 package. The part number it gives is RT9818B-30GB, but I can't verify the marking with the datasheet. The datasheet states "For marking information, contact our sales representative directly or through a Richtek distributor located in your area."

author: TheSteve
author_rank: Unknown
timestamp: December 21, 2015, 05:46:50 pm
content: The package and layout between two caps really points towards a regulator. Using the working unit you should be able to determine the pinout and output voltage. If you can't find the original part a sub can probably be located easy enough with that info.

author: Derresh
author_rank: Contributor
timestamp: December 21, 2015, 08:52:02 pm
content: Its definitely a voltage reg, since this that part got reduced to charcoal when putting in a 12V on a 5V input. Tho I didn't have a multimeter at work tomorrow I will take one and check what the voltage on this is tho was hoping someone had a data sheet for it so i could be sure im getting the proper replacement part in case it had anything more to it

author: stmdude
author_rank: Frequent Contributor
timestamp: December 22, 2015, 12:32:54 pm
content: Quote from: pmichel on December 21, 2015, 04:23:16 pmThe traces doesn't make sense for the SOT-23-5 package pinout in that datasheet. The top pins "at the top" should be NC, and there's no need to have pin 3 (GND) connected with a fat trace to an inductor.You've got very good google-foo though. I came up completely empty.
Open burning SMD Diode identification help ya - Page 1
Forum section: electronics / repair

author: yustech
author_rank: Newbie
timestamp: December 22, 2015, 06:25:35 pm
content: Hello friends of marvelous foruming.I caming across this Tube Screamer from a new friend,he just boughting it new then plugging to a Digital Technology(Digitech) 9VDC/1.3A adapter.it was smoking but quickly disconect it from open burning.He come seeing me.I plugging my BOSS 9VDC/200mA adapter and lucky it function lovely but I checking there's one burned part in the lovely printed cuircuitry board.I am thinking this is Diode type but I can only reading it as 1453 but what is it real coding naming in nature.Hoping you here helping me please.I enclosing picture so friend here looking to it also to ya but how am I doing that I would be very trying to do ya.

author: Anks
author_rank: Frequent Contributor
timestamp: December 22, 2015, 08:28:20 pm
content: Looks like a reverse polarity protection diode so almost any general purpose rectifier diode that will fit the footprint with do the same job.

author: yustech
author_rank: Newbie
timestamp: December 22, 2015, 08:38:46 pm
content: I am seeing...Thank you sir.Can I putting in 1N4148 or 1N4001.which one you like recommending to me use sir.

author: Jeroen3
author_rank: Super Contributor
timestamp: December 23, 2015, 08:35:04 am
content: Those are signal diodes. You'll need a (schottky) rectifier diode to do some current.Maybe an SS24 or PMEG4030ER depending on the shape and power supply.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: December 23, 2015, 09:08:06 pm
content: Er... 1n4148 is a small signal diode, yes.1n4001 is a 50V, 1A rectifier. It has a Vf of around 1 volt, though. A Schottky would indeed be better.

author: yustech
author_rank: Newbie
timestamp: December 24, 2015, 01:32:35 am
content: I am grateful for suggesting of recommend,I will telling the spec of the input..The tube screamer mini idealing using the ibanez adaper 9VDC/500mA.I am recommending the owner of effector am using BOSS because its having 9VDC/200mA.I thinkone of the two will be very saving for the effector.If I am looking for the schottky diode can I be using the above diode you are saying off.?If I am be looking at the paper data of this diode schootky which box I must looking for spec?I very much giving one thousand thank you for freinds here for having helping to my rescueing.
NHT SA-1 Subwoofer amp - schematic needed - Page 1
Forum section: electronics / repair

author: Joule Thief
author_rank: Regular Contributor
timestamp: December 21, 2015, 03:30:31 pm
content: Does anyone have a link to, or have a pdf schematic for the NHT SA-1 subwoofer amp? Unfortunately, no info shows up in my searches thru Google.The output circuitry and associated drivers seem fairly straight forward, but someone has been in this one before. Several small electrolytics seem to have been cut from the driver PCB.Thanks in advance and happy holidays to all.
Repairing a Soldering Station, Need to find connector replacement - Page 1
Forum section: electronics / repair

author: joshforester
author_rank: Contributor
timestamp: December 19, 2015, 04:17:51 am
content: Recently my cat thought it was a good idea to chew through the hose of my heat gun built into my soldering station.So I (think) I found the tubing, already had 24 AWG wire, but now I need to find this connector along with the crimp contacts. It's such a simple and normal type of connector, but I am not very skilled in Electrical devices. I am much more skilled 120V+ electrical.Anyone know where to find these?Where it connects to is to the right of the component labeled R7, and the second picture is the actual connector with the wires.

author: amc184
author_rank: Regular Contributor
timestamp: December 19, 2015, 04:28:25 am
content: It might be a JST PH. You need to post more info for a sure match though, like the pin pitch and a less potato quality picture.

author: Rasz
author_rank: Super Contributor
timestamp: December 20, 2015, 11:07:35 pm
content: why bother? just solder those wires permanently

author: Brumby
author_rank: Unknown
timestamp: December 21, 2015, 12:02:21 am
content: If the connector and contacts are in good condition, why not just chop off the old wires 3"-4" from the connector and solder the new ones to these. A bit of heatshrink and you're done.
Atten 8586 Solder Iron scratching clicking noise - Page 1
Forum section: electronics / repair

author: Shadow85
author_rank: Newbie
timestamp: December 18, 2015, 08:51:31 pm
content: Hi allI got the mentioned 2-in-1 rework station which is sold under different names to start learning hot air soldering.Strange thing is that if if use the solder iron, there is a strange noise which sounds like an old hard drive. Scratching/clicking.I'm wondering where it could came from. Its only when it already has reached the given temperature and just trying to hold it, you see a blinking dot in the down right corner of the display.If it heats up or cools down, i hear nothing.Of cause, i can send it back, but i'm interested what can produce such a sound.Thx for reading.

author: wblock
author_rank: Regular Contributor
timestamp: December 18, 2015, 09:23:41 pm
content: Does the clicking correspond with the "heater on" dot in the display? Then it's probably an audio effect from an inductor or other component. A relay would do that, too, but finding one controlling the heater in a modern soldering iron would be a surprise.

author: Shadow85
author_rank: Newbie
timestamp: December 19, 2015, 06:13:30 am
content: Quote from: wblock on December 18, 2015, 09:23:41 pmyes. But only when the dot is flickering. During heat up where the dot stays on, there is nothing.

author: Rasz
author_rank: Super Contributor
timestamp: December 20, 2015, 11:15:45 pm
content: arcing?quality of those units is pretty shit
Extension cord fault - Page 1
Forum section: electronics / repair

author: Tomorokoshi
author_rank: Super Contributor
timestamp: December 20, 2015, 04:01:08 pm
content: I needed an extension cord for something, so I went to the garage where I had use plugged in for a kind of a single-use purpose.I was going to use it inside, so I needed to clean it off. Here is what I found:One strand of the wire didn't get wound in, so in the insulation coating process it poked through. It's been in use like that for a long time.I don't recall getting shocked from it...Note that the strand is on the HOT line!
My first repair: a comm receiver - Page 1
Forum section: electronics / repair

author: mehdi
author_rank: Regular Contributor
timestamp: December 19, 2015, 01:55:48 pm
content: http://swling.com/blog/2015/12/icom-ic-r72-a-repair-story/

author: dr.diesel
author_rank: Super Contributor
timestamp: December 19, 2015, 01:57:34 pm
content: Nice score, I just bought a R75 myself.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: December 19, 2015, 02:06:13 pm
content: Very nice story and repair.Thanks for sharing.
General questions about LCD panel replacement - Page 1
Forum section: electronics / repair

author: ajrabassa
author_rank: Contributor
timestamp: December 22, 2015, 11:43:14 pm
content: When looking at potential repair projects, I'm coming across things with dead LCDs.If I can't find the service manual and parts list, how difficult is it to replace/source an LCD panel? I'm asking in general, I understand there will be outliers in both directions. Are they generally driven the same way in standardized form factors, where I can find a very similar LCD and put it in? Or should I assume I need to find the exact same LCD for a given device?

author: Stonent
author_rank: Super Contributor
timestamp: December 23, 2015, 12:03:33 am
content: I've seen it go both ways.For things like laptops, it's very easy as you can google the part number or go to a laptop LCD site and put in the model number.Many laptops have a standard type of connector so you have to match connector, resolution, size, connector location and whether or not it uses CCFL or LED.Resolution can be an issue because most laptops over 1366x768 have a different cable than ones that are 1366x768 or lower because it required both channels.Other devices I've had a harder time with if they aren't common things like portable video games. We had a timeclock at work that had a cracked screen and I googled every number on the LCD module and found absolutely nothing. When I contacted the vendor, they would not give me a part number, just said for us to send it in for refurbishing.

author: wraper
author_rank: Unknown
timestamp: December 23, 2015, 12:16:50 am
content: Your question is completely pointless without saying what kind of device, and preferably models too. There is no general answer.

author: ajrabassa
author_rank: Contributor
timestamp: December 23, 2015, 09:35:17 pm
content: Quote from: Stonent on December 23, 2015, 12:03:33 amThanks - this is pretty much what the consensus seems to be, it's either relatively easy to find, or it's next to impossible.
Philips HTS6600  repair - looking for PSU Mitsumi SRA2034EK schematic  - Page 1
Forum section: electronics / repair

author: Gixy
author_rank: Regular Contributor
timestamp: December 16, 2015, 06:56:34 am
content: This home-cinema set makes just low sound even with max volume. It is likely a PSU problem and some people have solved the problem by replacing an IC on the PSU board (STR-X6759). In order to confirm this I would like to examine the schematic but unfortunatelly it is not included in the service manual and I can't find it on the web. Anyone here ? Thanks in advance.

author: Gixy
author_rank: Regular Contributor
timestamp: December 17, 2015, 01:57:06 pm
content: I'm disapointed... Nobody here with experience on that particular PSU? It is based on this STR-W6759 regulator which I don't know how to test it to confirm it's potential failure.

author: PA0PBZ
author_rank: Super Contributor
timestamp: December 17, 2015, 02:17:09 pm
content: Without a schematic and with other people managing to fix it by replacing the STR... well, just replace it?

author: Gixy
author_rank: Regular Contributor
timestamp: December 17, 2015, 05:02:09 pm
content: Yes... It's on going. I ordered it to Digikey, only distributor to have it in stock, and the result is 11€ for the IC and 18€ for shipping. I prefered not to try some ebay's seller to be sure not to get a fake. So I cross my fingers now because without a schematic it will be difficult to find the failure's cause. All electrolytic caps seem good and I've checked passive components.

author: Gixy
author_rank: Regular Contributor
timestamp: December 18, 2015, 09:04:22 pm
content: Fixed!Impressive Digikey: ordered Wednesday night, delivered in France one day and a half later.

author: PA0PBZ
author_rank: Super Contributor
timestamp: December 18, 2015, 10:39:47 pm
content: Quote from: Gixy on December 18, 2015, 09:04:22 pm
Xenon strobe for cell phone - Page 1
Forum section: electronics / repair

author: westfw
author_rank: Super Contributor
timestamp: December 15, 2015, 02:31:41 am
content: This is a xenon strobe for a Nokia N8 cellphone. Does anyone have any idea how to get it to do anything outside of a phone?http://www.ebay.com/itm/Camera-Flash-Light-Flex-Cable-Xenon-Lamp-Replacement-Parts-FOR-NOKIA-N8-/171851581036

author: Brumby
author_rank: Unknown
timestamp: December 15, 2015, 05:24:19 am
content: You should be able to at least do a flash unit. Don't know if you would be able to get it to run fast enough for a strobe, but you never know.See if you can work out something from the schematic for the phone:http://pdadb.net/download/nokia_n8-00_rm-596_schematics_v2_0.pdfThe xenon flash connector is at the top right on page 2.

author: westfw
author_rank: Super Contributor
timestamp: December 15, 2015, 07:41:58 am
content: Thanks! That turned out to be a lot more helpful than I would have thought from a "service schematic"!(Pin 1 is on the side with the big cap; I got the LED to light!)
Hp1741a oscilliscope push lever - Page 1
Forum section: electronics / repair

author: Applemac
author_rank: Regular Contributor
timestamp: December 10, 2015, 09:45:38 pm
content: Hi was wondering if anyone knew where I could get a replacement lever for the 10x magnification switch. Whilst I was repairing the oscilliscope the lever snapped.

author: tautech
author_rank: Super Contributor
timestamp: December 10, 2015, 09:52:26 pm
content: Try Sphere:http://www.sphere.bc.ca/

author: Applemac
author_rank: Regular Contributor
timestamp: December 11, 2015, 08:35:54 am
content: Ive tried their site but they do not have any.

author: tautech
author_rank: Super Contributor
timestamp: December 11, 2015, 08:41:12 am
content: Quote from: Applemac on December 11, 2015, 08:35:54 am2 ideas.Email Sphere.Place a wanted add in the forum:https://www.eevblog.com/forum/buysellwanted/Don't forget to list the part # and/or add a photo.Surely someone will have a parts unit lying around.

author: DmitryL
author_rank: Regular Contributor
timestamp: December 11, 2015, 12:10:48 pm
content: Quote from: Applemac on December 10, 2015, 09:45:38 pmI have got a half-dead HP1740 scope. Fixed it until I realised that half of the analog ASIC is dead. It's pretty useless with one channel, so, probably, I can sacrifice it to source spare parts if someone is interested.

author: Gixy
author_rank: Regular Contributor
timestamp: December 11, 2015, 02:05:30 pm
content: http://Qservice.tv10x magnification switch? Isn't it 5x?http://www.amplifier.cd/Test_Equipment/Hewlett_Packard/HP_other/images/1741A.jpg

author: Applemac
author_rank: Regular Contributor
timestamp: December 12, 2015, 09:31:36 pm
content: DmitryL,If you could I would be very greatful for the part im looking for.

author: TAMHAN
author_rank: Frequent Contributor
timestamp: December 12, 2015, 10:11:32 pm
content: Hello,I need someone to nag me into firing up that 3D printer.So, if the spares deal doesnt work out, feel free to go Catalan against my mailbox (tamhan AEHT tamoggemon BALL com). It might take a few emails, as I havent commissioned that printer for one year (bought, built, but never, until today, printed a single item)...

author: Applemac
author_rank: Regular Contributor
timestamp: December 13, 2015, 09:03:35 pm
content: Quote from: Gixy on December 11, 2015, 02:05:30 pmNo it 10x if you look st the blue push buttons to the right of the screen of the oscilliscope your see one marked 10x. When you push it in a switch is moved via a plastic lever that connects the push botton to the switch on a pcb. Its this part that connects the push button to the switch that broke in mine.

author: TAMHAN
author_rank: Frequent Contributor
timestamp: December 14, 2015, 05:00:34 pm
content: Show me a pic, maybe I can print it.
GFG-8016D function generator - Page 1
Forum section: electronics / repair

author: electricspark
author_rank: Contributor
timestamp: December 14, 2015, 12:08:31 pm
content: Hi. I have a faulty GFG-8016D.I downloaded the manual from retrievo.com but it is missing page four of the schematic.I would really appreciate either a complete manual or the missing page.Thanks!
NZ Made Alron 4500 Guitar Amp - Page 1
Forum section: electronics / repair

author: Raff
author_rank: Regular Contributor
timestamp: December 12, 2015, 06:12:19 am
content: Hi everyone,I'm trying to repair a New Zealand made Alron branded guitar amplifier, its dated 1978 on the chassis.It has 2 MJ802 transistors as the output pair, an OC branded Folded Line reverb box, and is rated at 45 watts output.Its giving me a bit of grief so I was hoping someone may have a circuit diagram lying around?The fault is virtually no output at all. Maybe 100 milliwatts if lucky.I've tried signal tracing but there are some odd circuit design techniques in it that make no sense to me yet.The power supply is fine, +_ 40 volts, the speaker is fine, all transistors check ok with my meter, the electro caps have either been replaced or check fine.I've never worked on an amp like this one, it uses a transformer as the phase splitter for the output transistors.A schematic would make repair so much easier.Thanks,Raff

author: Shock
author_rank: Super Contributor
timestamp: December 12, 2015, 01:29:40 pm
content: If you want help with the repair side of things it helps to include decent photos and list what troubleshooting equipment you have.Regarding the schematic good luck on that, the look of these suggests a dirt cheap solid state amp. Could be helpful to know if they really were made there or some company just slapped a name on a Japanese brand.

author: Seekonk
author_rank: Super Contributor
timestamp: December 12, 2015, 02:11:47 pm
content: Transformer design like that should be a piece of cake. If you haven't blown out a speaker, output very near 0V, then the problem is likely the driver transistor to the transformer or circuit before that. Could be as simple as ghe audio electrolytic feeding the driver transistor.

author: Raff
author_rank: Regular Contributor
timestamp: December 14, 2015, 07:43:06 am
content: Well I got the old girl working.Turns out my scope probes went faulty.It makes it hard when you have to troubleshoot your troubleshooting equipment before troubleshootingA few old electros replaced, a bit of rewiring and a tidy up and away she goes.Its actually not a bad little combo, sounds pretty good to my ears anyway.Thanks,Raff
Removing knobs advice? - Page 1
Forum section: electronics / repair

author: Smidge204
author_rank: Newbie
timestamp: December 13, 2015, 10:31:03 pm
content: I'm seeing if I can repair a sticky select switch on a Hitachi V-1565 scope. Feels like there's some sort of grease or something inside that's dried up.In order to get at the switch I need to take the frame apart, at least partially, which means getting the printed plastic control label card off to get at some screws behind it, which means pulling the knobs off.They are on SUPER tight, and since the scope is otherwise in perfect working condition I'd like to not wreck the thing. Only two of the knobs (Volts/Div selectors) have setscrews. A few of the knobs have plastic tubes that reach further back and those slide right off. Most of them, though, feel like they're glued on.Any advice for removing these things without damaging anything? Or maybe there's a less direct way to "heal" the gooey switch? I can't see the actual switch body.Here's some photos!http://www.smidgeindustriesltd.com/scope01.jpghttp://www.smidgeindustriesltd.com/scope02.jpg

author: langwadt
author_rank: Super Contributor
timestamp: December 13, 2015, 10:38:56 pm
content: Quote from: Smidge204 on December 13, 2015, 10:31:03 pmsome knobs have a removable end cap with a nut/screw behind it

author: Smidge204
author_rank: Newbie
timestamp: December 13, 2015, 10:46:42 pm
content: I hadn't considered that, but looking at the knobs very carefully with a flashlight and magnifier they all appear to be single piece molded plastic!

author: Fraser
author_rank: Super Contributor
timestamp: December 13, 2015, 10:47:13 pm
content: A classic and gentle method to remove knobs is to take a fabric or silk ribbon, wrap it once around the shaft so the the ends are set at each side of the knob. Pull the ribbon tails and the pulling force is gently applied to the fragile knob.Other methods involved proper knob pullers that look a little like a simple IC puller. U shaped metal with a claw at the ends to catch under the knob. Not to be used on knobs with skirts ! ...why? You are sure to rip the skirt off in chunks!Plastic straps that slip behind the knob and are levered against the panel have also been used but I never found them to work well.Metal levers may be used if appropriate padding is used. Cardboard works well.Always check that a knob is not a collet type with hidden screw or nut under a knob cap. The number of times I have seen abused knobs and broken shafts because people mistook a collet knob for a simple push on type. Those collets grip very well !There is often an adhesive foil tape used on splined knobs to improve knob grip. This can make removal harder.Fraser

author: Smidge204
author_rank: Newbie
timestamp: December 14, 2015, 12:00:19 am
content: Quote from: Fraser on December 13, 2015, 10:47:13 pmThat did it! All I had readily available was some plastic ribbon but it did the trick wonderfully. Almost effortless.Many many thanks! Hopefully the rest of the repair attempt goes as smoothly!
Car alarm / keyfob microswitch sources ?? - Page 1
Forum section: electronics / repair

author: meeslef
author_rank: Newbie
timestamp: December 12, 2015, 11:18:28 pm
content: Hey there,I have a car with an old mongoose brand car alarm, they are two button and i've already scrounged two microswitches off the remotes to repair them.Does anyone know a _reputable_ source for these micro switches ??Tried browsing rs components, mouser and my search-fu doesn't seem to find them. I know you can get them on ebay / Chinese wholesale sites, but i really want to know what i'm getting is going to last since they take a fair beating.These are roughly the microswitches i'm looking for. (need through hole not pcb mount but just to get an idea for size and type).http://www.ebay.ie/itm/micro-switch-repair-remote-key-fob-MG-ROVER-25-45-75-ZT-ZR-TF-ZS-Montego-/321907055239?hash=item4af327da87:g:1fgAAOSwHnFVh9mRCheers

author: Muttley Snickers
author_rank: Unknown
timestamp: December 12, 2015, 11:49:13 pm
content: I have a remote on the bench for a customer which is about to get new momentary switches and as these remotes are over 10 years old and no longer available we have little choice, we could upgrade the receiver and give them new remotes but they are a bit frugal to say the least.We use these listed below but use a scalpel to cut them down in height as we don't want them to transmit on the slightest touch.http://www.jaycar.com.au/search?text=tactile+switch&CSRFToken=1e7425ca-25da-4b6f-a636-ebb7384ca8b8http://www.altronics.com.au/search/all/?sr=tactile+switch

author: meeslef
author_rank: Newbie
timestamp: December 13, 2015, 12:09:16 am
content: CheersFor all you players at home they are "tactile switches" and not microswitches per se...I think i'm on the right track now, much obliged.

author: tautech
author_rank: Super Contributor
timestamp: December 13, 2015, 12:42:45 am
content: Just one of many sets that are available on Aliexpress:http://www.aliexpress.com/item/Free-Shipping-10-models-250-pcs-Tactile-Push-Button-Switch-Micro-Switch-Car-remote-control-button/32402262312.html?spm=2114.01020208.3.2.AbZxh2&ws_ab_test=searchweb201556_4_79_78_77_82_80_62,searchweb201644_0,searchweb201560_4More:http://www.aliexpress.com/wholesale?spm=2114.01020208.8.14.jsyfAO&initiative_id=QRW_20151212163646&SearchText=switch+tactile&productId=32402262312