hybridfree/eevblog-posts huggingface dataset:
URC MX-6000 Remote - Page 1
Forum section: electronics / repair

author: Bigfoot1993
author_rank: Newbie
timestamp: December 20, 2017, 03:07:41 am
content: I have a question that i hope someone can answer. I was a certified installer for the URC MX ine of remotes. I own the URC MX-6000 touchscreen. It was a store demo model from where i worked. My battery failed after 2 years. I ordered a replacement from URC. I think it was $120 american, expensive but i thought it best. It also failed after barely 1 year. I was told that i had left it on the charging dock to long, and i should remove it when fully charged. This goes against the treatment of the first battery as it was also left on the charger both before i owned it while a store demo, and when i programmed it for my home. I then got one off E-bay for about $50. With this new battery i have a lot of screen issues, and button problems, and the battery doesn't seem to hold the charge for very long. I assumed i needed to clean the remote. However I tried putting the remote, minus battery on the charging stand and it seems to be functioning fine. This gave me a crazy idea which is me question. Could the E-Bay battery not put out the correct amperage? It is a 3.7 VDC-5200 mAh-19.24 WH. Unfortunately i got rid of the old battery when i got the new one. URC tech support is not helpful at all.Any and all help would be appreciated.

author: ivi_yak
author_rank: Regular Contributor
timestamp: December 21, 2017, 11:19:01 pm
content: could you specify your question

author: Bigfoot1993
author_rank: Newbie
timestamp: December 22, 2017, 07:33:35 am
content: I have no idea what the original battery was speced at. I was hoping someone could tell me if the battery i am using could be a poor replacement? Knowing it is a chinese "one hung low" replacement.

author: ivi_yak
author_rank: Regular Contributor
timestamp: December 22, 2017, 11:57:45 pm
content: simply you can measure current consumption and choose your bat
Anritsu MS9710C problem - Page 1
Forum section: electronics / repair

author: domlaco
author_rank: Newbie
timestamp: December 17, 2017, 07:46:52 pm
content: Hello everyone,I need help with my new acquisition, an Anritsu MS9710C spectrum analyser, which powers on with a "slit-1 error", as you can see on the picture below.does anyone have an explanation, or any kind of idea about solving this problem?Thanks a lot in advance!Dominique

author: SMB784
author_rank: Frequent Contributor
timestamp: December 19, 2017, 12:13:46 am
content: While I know nothing about the unit itself, given that it is an optical spectrum analyzer, it needs a diffraction grating and a slit (probably adjustable) to disperse the light onto a CCD for analysis. The slit-1 error likely means that the slit is not behaving correctly. Given that it is just a simple slit, I would venture to guess that the driver that controls the slit has a problem, or maybe the optomechanics that adjust its width are malfunctioning in some way
GFCI nuisance trips HP VXI power supply - Page 1
Forum section: electronics / repair

author: forrestc
author_rank: Unknown
timestamp: December 18, 2017, 11:11:35 am
content: I have a couple HP high powered VXI chassis which trip GFCI's whenever they are plugged in after being unplugged for a while. I've taken to plugging them into a UPS previously unplugged from the wall, and then re-connecting the UPS. They also tend to trip GFCI's during certain brief sag events (say when a large load is turned on). There is a note in the owners manual about these not being compatible with GFCI's. Because of the note and because every one of these I've ever had reacts the same way, this is obviously a design fault. I'm not particularly eager to give up the protection a GFCI gives me in this environment, so I'm wanting to fix this shortcoming.My initial guess was incorrectly sized input filter caps or other similar circuitry shunting enough current from the lines to ground to trip the GFCI. So, tonight I took a spare power supply I had laying around and opened it up. It looks like there is a delta-branded input filter (15deeg3ha). This particular filter claims to have, 0.12mH + 6uH on each line, and a pair of 2.2nf filtering caps (line to ground). On the main board, there is a 1uF and a 2.2uF AC cap directly across the line, and and two 10nf Y2 caps from the line to ground. I think that's pretty much it before the rectifier. So it looks like we have a total of around 12200pf from each power line (line and neutral) to ground. (Please correct my math if I got my units wrong)I've found a few documents about sizing these which indicate the max capacitance is somewhere around 3300-4700 pf depending on the capacitor type to avoid excessive leakage... So 12200pf seems excessive. My initial thought is to leave the line filter in place (maybe replacing it with a fresh one), and removing the Y2 filters from the main board (leaving the X caps across the line). But I'm pretty far from a mains-connected power supply expert. Could someone let me know if I'm analyzing this correctly, and maybe make some suggestions if I'm not?
Can somebody please I.D. these diodes... - Page 1
Forum section: electronics / repair

author: peteb2
author_rank: Regular Contributor
timestamp: December 18, 2017, 04:51:18 am
content: They at least measure as a diode on my DMM diode function but the color code is referring to perhaps a zener voltage? It's an old switchmode style circuit too. I faintly recall seeing this kind of package in the past but never thought to learn what they truly are... Thanks.

author: schenkzoola
author_rank: Unknown
timestamp: December 18, 2017, 05:58:48 am
content: This is a MELF package. See the following link, page 3.https://www.vishay.com/docs/88912/diodesgroupbodymarking.pdf
HP 5350B Microwave Counter Help needed with replacement for SMA cable - Page 1
Forum section: electronics / repair

author: Ordinaryman1971
author_rank: Frequent Contributor
timestamp: December 17, 2017, 03:57:52 pm
content: Hello everybody I have HP 5350B that has destroyed SMA cable assembly that goes between microwave module and synthesizer.The cable is about 6" long. I have some other ones but not the one with those connectors.There is somebody there that knows how to get one/fix one/have one.Thank you.

author: dacman
author_rank: Frequent Contributor
timestamp: December 17, 2017, 09:22:44 pm
content: Looks like SMB to me. Are those panel threads used?

author: Ordinaryman1971
author_rank: Frequent Contributor
timestamp: December 18, 2017, 03:09:34 am
content: it's a pigtail between two modules inside of the counter. I've fixed it already, took it apart, to pun intended, soldered it back together and it works... not sure about the performance because I can't really verify it. I want to get replacement anyway just to ensure the quality of the signal.I couldn't crimp the connector correctly... but I guess I've done my best.And yes, it is SMB, I've found replacement already, $3.44.

author: Ordinaryman1971
author_rank: Frequent Contributor
timestamp: December 18, 2017, 03:11:45 am
content: Yes the connector is screwed into the mounting plate that mates with the connector on the other side of it... very clever design.

author: xrunner
author_rank: Super Contributor
timestamp: December 18, 2017, 03:16:32 am
content: They can be home made if you are of the mind to tackle it. The SMB connectors and cable is available on numerous sites and Ebay sellers. It's not too difficult as I have made them myself.
HP 6966A Lab Power Supply Manual - Page 1
Forum section: electronics / repair

author: Schnibbelwind
author_rank: Newbie
timestamp: December 05, 2017, 06:20:27 pm
content: Hi,I got my self an HP 6966A lab power supply in very good condition, from the dumpster. But when I switch it on, it's output voltage jump to 60V.(The HP 6966A is a 0-36V and 0-10A power supply)Now I'm trying to Fix it and a manual with an schematic could save hoursHP 6966A, 6965A, 6964A and Helmut Singer(Harrison) LVR 6367A are similar.

author: oventech
author_rank: Contributor
timestamp: December 06, 2017, 03:44:07 am
content: Found this hope it is what you are looking for.https://www.keysight.com/en/pd-836652-pn-6690A/6600-watt-system-power-supply-15v-440a?pm=PL&nid=-35679.384174&cc=US&lc=eng

author: Schnibbelwind
author_rank: Newbie
timestamp: December 06, 2017, 06:00:19 am
content: Thank you for the link, but this model is far more modern than my.The 6966A is from the 1970s, with SCR preregulation and GA-Transistor.http://www.helmut-singer.de/stock/1373.html]http://www.helmut-singer.de/stock/1373.html

author: oventech
author_rank: Contributor
timestamp: December 08, 2017, 01:36:09 am
content: Found this on the Power Supplieshttp://hpmemoryproject.org/an/pdf/an_06-65.pdf.

author: oventech
author_rank: Contributor
timestamp: December 08, 2017, 01:45:33 am
content: Sorry the link did not work. Looked up "HP 6699a Lab power supply" got to a reprint of a 1965 power supply application PDF. Covers features of the power supplies. Might give you an idea on yours. Hope it helps.

author: JoeB83
author_rank: Regular Contributor
timestamp: December 17, 2017, 04:02:46 pm
content: Quote from: oventech on December 08, 2017, 01:36:09 amIf you remove the period from the end of the link it works just fine.
Alpine 3566 help - Page 1
Forum section: electronics / repair

author: Devcam
author_rank: Newbie
timestamp: December 16, 2017, 05:01:48 am
content: Hi my amp cycles on n off for a while before it finally settles to normal and works fine .i have changed power supply caps. Any suggestion thanks.Sent from my SM-J320F using Tapatalk

author: SMdude
author_rank: Frequent Contributor
timestamp: December 16, 2017, 10:04:35 pm
content: I have an amp that used to do that too(not an alpine though).I sprinkled a bit of heat (with a hot air gun or solder station)about the place while it was turning on and found that when I heated up the really big caps in the middle of the amp board, it very quickly started running. I then replaced these caps, and just about every other electro for the hell of it as the amp is older than 25 years.No more problems since!
Razer Mako schematics - Page 1
Forum section: electronics / repair

author: edgelog
author_rank: Regular Contributor
timestamp: December 13, 2017, 02:48:20 pm
content: I'm trying to troubleshoot a Razer Mako speaker system. I've localized the (or at least one of the...) problem to the power supply. It has two separate switched power supplies for different rails and one of them is based on the 3845B current mode controller IC. This IC doesn't get any Vcc, but I can't figure out where that Vcc is supposed to come from. It's a multilayer board, which doesn't make it any easier.I asked Razer for a schematic, but no go. I've searched the interwebs, found nothing. Does anyone here have them, or have an idea where to find them?

author: edgelog
author_rank: Regular Contributor
timestamp: December 16, 2017, 05:33:17 pm
content: Followup: I never did get hold of the schematics, but found the problem anyway. Wrote it up here:https://www.ursecta.com/2017/12/16/razer-mako-no-click-of-death-fix/
Repair challege (Just kidding) - Page 1
Forum section: electronics / repair

author: TerraHertz
author_rank: Super Contributor
timestamp: December 15, 2017, 12:00:11 am
content: Here's a street-tossed battery power backup system, that I picked up solely to take pics of the horror.They appear to have been in a basement or something, where the sump pump failed. Ie they were immersed in dirty water for quite a while. Even from the outside looking like complete writeoffs. Probably not even any salvageable components.Sure enough... after breaking open the case with an angle grinder, due to rusted-in screws... yuk.Sad.

author: james_s
author_rank: Super Contributor
timestamp: December 15, 2017, 01:32:33 am
content: I bet I could fix the one on the right, I've restored water damaged equipment in worse shape than that. Now whether it's worth putting any effort into repairing I don't know. These days I only bother messing with inverters of the true sine type.

author: TerraHertz
author_rank: Super Contributor
timestamp: December 15, 2017, 01:51:20 am
content: The one on the right is a mains to battery charger. The larger one is a battery to sine wave mains inverter. I'm guessing they were used as a pair, with the charger placed a bit higher up so it didn't get as dunked. A few components in it are worth salvaging.They are both now reduced to scrap metal.The same street toss pile had a lot of hand and power tools, in the same condition. Ie been underwater for a while. I bet someone was pissed when the disaster was discovered.

author: Cyberdragon
author_rank: Super Contributor
timestamp: December 15, 2017, 11:02:42 pm
content: You should have given it to Shango066. He would have gone "this looks like shit!" then a few minutes later it would have magically decided to start working.
Looking for a source for these parts - Page 1
Forum section: electronics / repair

author: HardCoreElectronics
author_rank: Newbie
timestamp: December 11, 2017, 07:55:44 pm
content: I am lost for time looking for a source on this power cord grommet.Anyone familiar with this type? The slot slides on to a metal frame in a clothes dryer.Grommet measuresOD 35mmID 16mmsmaller OD 26.5mmSlot OD 20mmMaterial: Similar to the wire jacket PVC insulation.https://drive.google.com/open?id=1CPGK46uozUO8wAZG4sYJA8szLcSsY2_JAnd also this type of connector with unusual dimensions. 8mm x 16mmhttps://drive.google.com/open?id=1ASZv7Paj5gLdePFBOWFgMJYqPhNoTZjVhttps://drive.google.com/open?id=1u2JoGCIbQI3WYcIJ14pR9nJrMbF2Ji6v

author: EPTech
author_rank: Regular Contributor
timestamp: December 12, 2017, 08:41:41 am
content: HI there,For the gromet, try this:http://www.essentracomponents.com/en-ca/For the tab, maybe this:https://benl.rs-online.com/web/c/connectors/terminals-splices/crimp-tab-terminals/?applied-dimensions=4294692956

author: HardCoreElectronics
author_rank: Newbie
timestamp: December 15, 2017, 05:42:38 pm
content: Thanks for the input!I ended up making an extension cord with an electrical box, dryer outlet and another dryer cable. The cost and time to wait for the parts required was insurmountable to just making up an extension cable. Local electrical code rules allow for it.
Technics SU-Z65 repair help - Page 1
Forum section: electronics / repair

author: ebaketa
author_rank: Newbie
timestamp: December 15, 2017, 08:39:08 am
content: Hello there, i'm repairing Technics SU-Z65 amplifier and I need help, I have checked all output transistors, they are all correct, I think the issue in the integrated circuit of the Panasonic AN7060, for which I have very little information, I found the data sheet but unfortunately in the Japanese language, so I do not understand.I tried to connect it as an operational amplifier with a negative feedback and at the output I did not get anything.Please if anyone has the experience and the will to help me test this integrated circuit?Thank you in advance!PINOUT:1 - Input2 - N.F.B. (feedback)3 - NC4 - GND5 - (-VCC)(-6V)6 - Output7 - T-P ( idon't know what is thip)8 - (+VCC)(+60V)9 - (+VCC)
Compaq Portable - display loses sync - display garbage temporarily - Page 1
Forum section: electronics / repair

author: alank2
author_rank: Super Contributor
timestamp: December 14, 2017, 08:11:27 pm
content: It works 99% of the time, but it will occasionally just for a blip lose sync and/or display junk for a moment. I'm not sure if it is the monitor or if it is the video board, I suppose it could be either. Any recommendations on what to look at first?

author: CJay
author_rank: Super Contributor
timestamp: December 14, 2017, 08:42:14 pm
content: Could well be both but I'd start with the video card, which Compaq Portable is it?

author: alank2
author_rank: Super Contributor
timestamp: December 14, 2017, 08:54:53 pm
content: It is the original compaq portable - 8088 with a pair of 360K floppy drives. The monitor is an odd thing where it can do dual signal - you can press ctrl-alt-< for MDA and ctrl-alt-> for CGA and it will change the display. The MDA looks much better with 9x14 characters, in CGA mode I think it has 8x8 characters and you can see scanlines. The video card is a full length and connects to the monitor with a 2x5 100 mil header.

author: james_s
author_rank: Super Contributor
timestamp: December 14, 2017, 09:45:41 pm
content: These were quite unique machines. The dual mode card supported CGA for compatibility reasons and could output color to an external monitor but the built in display was monochrome. I would start by carefully inspecting the cable to the internal monitor and if that looks ok you might have a cracked solder joint in the monitor itself. If you have an external CGA monitor to try see if that exhibits the loss of sync, or you could put a scope on the sync signals.I had one of these once, complete with a nice padded carry bag. Sometimes I wish I'd kept it.
LCD Panel Failure - Page 1
Forum section: electronics / repair

author: Votality
author_rank: Contributor
timestamp: December 14, 2017, 11:59:26 am
content: Just out or interest what would have caused this fault?Looks like a fault with the LCD itself?? Not the electronicsSent from my iPad using Tapatalk

author: Armadillo
author_rank: Super Contributor
timestamp: December 14, 2017, 01:17:52 pm
content: Polarized front glass is cracked. :-(

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 14, 2017, 01:19:00 pm
content: It maybe looks like heat damage?

author: Votality
author_rank: Contributor
timestamp: December 14, 2017, 01:23:47 pm
content: No crack at all.. heat do you think??Sent from my iPad using Tapatalk

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 14, 2017, 01:29:57 pm
content: Quote from: Votality on December 14, 2017, 01:23:47 pmIt could still be a crack, but on the inner layers. If you put a lot of blunt pressure on a monitor it could happen.

author: Armadillo
author_rank: Super Contributor
timestamp: December 14, 2017, 01:58:35 pm
content: Quote from: Armadillo on December 14, 2017, 01:17:52 pmfrom the inside..... though the outside may be smooth to the feel.

author: Koray
author_rank: Regular Contributor
timestamp: December 14, 2017, 09:33:34 pm
content: Could be humidity or some sort of oil ingress into the diffuser layers? K.

author: james_s
author_rank: Super Contributor
timestamp: December 14, 2017, 09:36:37 pm
content: That's unlike any failure I've ever seen before. It looks like maybe the layers are delaminating somehow. Certainly does *look* like the panel itself although that's no absolute guarantee. You could unplug the panel from the driver board and see if it goes entirely white.
Air Conditioner Don't Start - Page 1
Forum section: electronics / repair

author: sfiber
author_rank: Regular Contributor
timestamp: December 14, 2017, 07:19:56 pm
content: Hi friends.I have an air conditioner that doesnt work for years and I need to repair it now. It doesnt have any response after powering up from onboard switch or via remote controller. In photo there is a little rectifier ac-dc converter card and 7805 power regulator.When I measured 7805 output with 7805's ground pin I see 4.99V but when I measured output with ac input reference I see 110.3 V AC. Should I see ac on 7805's output.(Same AC Value on 7805 input pin)

author: Kilo Tango
author_rank: Regular Contributor
timestamp: December 14, 2017, 07:28:21 pm
content: Doubt it.Ken

author: hermit
author_rank: Frequent Contributor
timestamp: December 14, 2017, 08:01:38 pm
content: Quote from: sfiber on December 14, 2017, 07:19:56 pmI'm not one hundred percent sure what you mean here. What AC input reference do you mean? You hooked up your meter between an AC and DC voltage or you switched your meter to AC mode or both?

author: sfiber
author_rank: Regular Contributor
timestamp: December 14, 2017, 08:06:35 pm
content: I mean;measuring between 7805 output and Notr of AC line with AC mode of DMM.

author: Armadillo
author_rank: Super Contributor
timestamp: December 14, 2017, 08:35:17 pm
content: Oh I remember you, the kitchen gas detector guy.Better be careful, there are the hot ground and the cold ground. Better read up and take the correct ground.See the shaded demarcation line on the pcb, that's the separation between the danger side and the safer side.Edit: Any DC voltage there?Edit: I think its not safe for you, so I will stop from here.
Testing Voltage Through PCB Via? (LEDTV repair help wanted.) - Page 1
Forum section: electronics / repair

author: MiserablePixels
author_rank: Newbie
timestamp: December 11, 2017, 04:49:17 am
content: I'm trying to diagnose my LEDTV mainboard and am following the standby voltage (3.3). It is evidently not sending any signal back to my powersupply to enable the rest of the pins because the rest of my 12v rails don't have any power unless I use a jumper across "POWER ON" and "AC OFF DET", at which point the 12v pins all get a solid 12.5v.Testing continuity, I find the 3.3v arrives at the mainboard and reaches the bottom of the PCB but when I test the via to see voltage, I get nothing(well 0.002). So there is continuity to the bottom but nearly zero voltage. Shouldn't I be able to see 3.3 on the via?For reference, the TV is not powering on, no standby lights, no clicking, just nothing. The PS has 3.3v standby voltage and my bridge rectifier is reading in spec but I can't figure out the next step without being able to follow the 3.3 rail to see why nothing is coming back from the mainboard. All the caps look fine, the fuse is fine, nothing appears damaged or shows signs of ever getting hot, no smells, nothing obvious. I'm trying learn something here and prevent adding to the floating garbage island. I can't see any reason why this piece of technology should be wasted.BTW it is a Sony KDL-55W802A. I'd appreciate any input!

author: Rasz
author_rank: Super Contributor
timestamp: December 11, 2017, 01:00:16 pm
content: is it shorted?

author: oventech
author_rank: Contributor
timestamp: December 12, 2017, 03:59:34 am
content: Have seen Via's in which the solder connection was bad. Had to reflow in order to get the board to work. Too much flux in via, plus incomplete thru hole plating.

author: MiserablePixels
author_rank: Newbie
timestamp: December 14, 2017, 06:27:49 am
content: I attempted to reflow the mainboard today, 375F @ 10 minutes. No change.Something I noticed though was when I unplugged the cable running between the power supply and the main board and ran a lead directly between the 3.3v pin socket on the cable to the male pin on the mb socket, I was able to read 3.3 volts on the via! It confuses me because my meter shows continuity through the cable, but the voltage is getting lost somewhere. So, either the male or femal socket/plug may be bad?I doubt that this is the root of my whole issue, but it may explain why the rest of my power supply isn't getting signaled by the mainboard. I've ordered a replacement cable and I went ahead and ordered a new mainboard. Hoping it solves the issue. It isn't the method I wanted to use to resolve this but I'm not getting very far on my own.
Need help with Agilent DSO1024A/Rigol DS1204B power supply voltages - Page 1
Forum section: electronics / repair

author: sbvr4
author_rank: Contributor
timestamp: December 13, 2017, 10:16:08 pm
content: Hello, I have a Agilent DSO1024A (Rigol DS1204B) Oscilloscope that I am trying to debug. I was wondering if anyone knows the proper voltages that should be read coming out of the power supply? I'd like to power the unit externally to verify it functions before I fix the PS.Thank you,Sbvr4
How to open/refurbish HP 1250-1091 BNC connectors - Page 1
Forum section: electronics / repair

author: ingowien
author_rank: Regular Contributor
timestamp: December 13, 2017, 07:52:17 pm
content: Hi,does somebody know how to open these HP BNC connectors correctly? Some connectors on my HP 8673B are in bad condition and should be replaced or at least cleaned. Some time ago I tried to open similar BNCs on a 8593E and all I managed was to ruin the knurls but the nuts didn't move. They seem to be either tightned very strong or are stuck or glued.- Is there a correct way or trick to open these nuts (warm air, WD-40, special tools or just brute force)?- Is there a way to refurbish the connectors? Do you know how they are plated and how to clean them? These are only low bandwidth aux connectors but they shouldn't be in such bad shape.- Does someone have replacement connectors?best regardsIngo

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: December 13, 2017, 10:06:26 pm
content: Can't say about those specific HP jacks, but I am using small interdental brushes and Kontakt Gold2000 to clean BNC jacks. In case of more dirt/oxidation I have a small, slightly conical diamond burnisher which is a repurposed pre-used (so not to bite too much) dental rotary insert.
Goldstar 7020a screen goes dim after a few seconds - Page 1
Forum section: electronics / repair

author: corronius
author_rank: Newbie
timestamp: December 13, 2017, 09:27:09 pm
content: I bought a Goldstar 7020a on craigslist. before I bought it I plugged it in and connected one of the leads up to the test squarewave generator and everything seemed fine (the trace was very bright) but a few days later when I turned it on the trace was only bright for a few seconds after being powered on (https://photos.app.goo.gl/uCln92dJtA1ySQxf2)do you know what could be wrong with it?
Kenwood TS-590 that's had 1kW of LF RF up its RX antenna port! - Page 1
Forum section: electronics / repair

author: Chris Wilson
author_rank: Super Contributor
timestamp: November 30, 2017, 12:19:17 pm
content: Due to a failure in a TX / RX relay after a 1kW amp on 136kHz my venerable Kenwood TS-590S transceiver got a kilowatt of 136khz up its receive antenna port. The result of course is not good. I was disappointed to find Kenwood cannot supply a new RF board, and they class this 5 year old rig as obsoleteI can get a US spec RF board from America for about £200 and I *THINK* it only differs in not having two trimmer caps and two inductors that make up the broadcast band filter on European spec boards. But before I take this costly and somewhat risky purchase I wanted to have a go at seeing if I can determine the extent of the damage. I fixed another issue ages ago, but this is far worse. I need to know at what frequency a modulated test signals should be injected, based on this service manual block diagram to see if the damage stops before the mixers or goes beyond them. I am not sure what frequency to inject should I find a dead mixer. In other words after a dead mixer, can anyone help please? Thanks!

author: CJay
author_rank: Super Contributor
timestamp: November 30, 2017, 04:32:56 pm
content: Is it just 'deaf'?Does it TX?On the correct frequency?The service manual tells you that for a 14MHz, -113dBm input signal at the antenna jack you should be seeing a signal at -107dBm after the first RX mixer 1 so I'd be injecting a -107dBm signal after that mixer at 11.374MHz which is the first IF filter centre frequency, if I were testing it.After 1st RX Mixer 2, -102dBm @73.095MHzIf you need a hand and you're local ish to Manchester, let me know

author: Paull Karll
author_rank: Newbie
timestamp: December 12, 2017, 10:43:59 pm
content: Shop for a "parts only" buy off of QRZ's swap meet forum.www.qrz.comEasiest way to find a part that you will fit.

author: Chris Wilson
author_rank: Super Contributor
timestamp: December 13, 2017, 12:12:13 pm
content: Looking at buying a new US spec RF board, as far as i can tell it only differs from the EU spec boards by not having 2 small chokes and two small ceramic trimmer caps to form a broadcast band filter on the EU spec machines. the pads and through holes are there so i could swap my components or just fit new. but that's assuming the schematics tell the full story..... Thanks Paull
Global Specialties 3600 Logic Analyzer front panel connector - Page 1
Forum section: electronics / repair

author: rodd
author_rank: Regular Contributor
timestamp: December 23, 2017, 08:38:20 pm
content: Hi,I have just bought one of these for a reasonable price at Ebay, but it does not come with the data cables.I downloaded the user manual but I could not find any reference to the pinout and the connector type that is used in this instrument.Does anybody have a similar one of any other document which makes reference to these connectors?ThanksRoger
Vizio E241-A1 - Page 1
Forum section: electronics / repair

author: neo
author_rank: Super Contributor
timestamp: December 13, 2017, 04:13:39 am
content: The screen is fine but the power supply has issues, i replaced the caps and checked the bridge rectifier but the TV will not turn on. The only thing it does is when you plug it in and it makes a light buzzing noise.Any suggestions? Please and thank you.
Repair Bin Full circuit Fellowes 320C-2 shredder - Page 1
Forum section: electronics / repair

author: Paull Karll
author_rank: Newbie
timestamp: December 12, 2017, 10:23:50 pm
content: I recently repaired my Fellowes 320C-2 cross-cut paper shredder's Bin Full Circuit. Problem: Bin Full light keeps coming on and shutting down the shredder with a red fault light even though there is no obstruction and the lights have been cleaned.Solution: Take the top off the shredder and look at the circuit board. Jumper JT2 Full has a four wire connector on it. These wires go to the LEDs for the light beam sensor circuit. Two black wires, one red & one orange. Short the black & orange wires! This validates the received signal to the circuit board. That's it - put it back together & return it to service.Paull K.
DSO 6054A DC offset problem - Page 1
Forum section: electronics / repair

author: maxtee
author_rank: Contributor
timestamp: November 21, 2017, 06:32:19 pm
content: I have a DSO6054A, with DC offset issues. The picture is attached. The problem is on all 4 channels. No matter what I try the signal trace can't be centered using the DC offset control. The signal trace is railed to the bottom of the screen. Any help will be greatly appreciated.

author: Neganur
author_rank: Unknown
timestamp: November 21, 2017, 06:46:33 pm
content: Is that without anything connected to the inputs?

author: EPTech
author_rank: Regular Contributor
timestamp: November 22, 2017, 12:01:46 am
content: Hi there,Do you have experience with this scope, is it your own? On some scopes you need to press the trace positioning wheel. in order to bring the trace to the center of the screen.Then again it is also measuring a large negative value. If it is a general problem, It mail be a faulty supply rail or some reference voltage to the ADC. Take it apart!Happy hunting,Pascal.

author: Jwalling
author_rank: Unknown
timestamp: November 22, 2017, 11:40:06 am
content: Have you tried running the user calibration?

author: HighVoltage
author_rank: Super Contributor
timestamp: November 22, 2017, 11:45:05 am
content: I have seen this problem a lot on older scopes, never on a modern DSOWhat happens if you press DEFAULT setup?What happens if you apply a signal at the inputs?Is this problem right away after a startup?How did this problem come about? Did you overload the input?

author: maxtee
author_rank: Contributor
timestamp: December 07, 2017, 03:41:54 pm
content: Thanks guys for your response. The following steps have been tried without any success. I have no experience with this scope. I did use the repair manual to check for voltages and they seem to be OK. The self-tests results do show pass. Since applying input signal on any of the 4 channels have no effect, I suspect something wrong with the front end section. Perhaps one of the voltage is not correct. I have verified Three of the Hybrid power rails 5V, 12V and 3.3V to be within specs.- Default setup. No effect.- User cal. User cal starts but abruptly quits within seconds.- Applying signal doesn't show anything on the screen. That is true for all 4 channels.- The scope had a damaged 12V LDO which supplies12V to the input hybrid chips for all 4 channels. I replaced the LDO.- Yes, the problem starts right away after startup.- I don't think overloading since the problem is present on all 4 channels. What is the likelihood of all 4 channels getting exposed to overloading?- trace positioning wheel has no effect on the DC offset.- Yes, this without any signal present at the input.

author: Neganur
author_rank: Unknown
timestamp: December 07, 2017, 04:35:11 pm
content: Yup, sounds like the offset DAC is not doing its job. No idea if that's inside the ASICS or just a matter of another rail being blown too

author: maxtee
author_rank: Contributor
timestamp: December 11, 2017, 03:07:35 am
content: Any idea what power rail that might be or which chip controls the DC offset?
Projector not turning on, lights flashing - Page 1
Forum section: electronics / repair

author: Seppo
author_rank: Newbie
timestamp: December 09, 2017, 05:21:29 pm
content: Hi!I got hold of a non fuctioning 5 years old Epson EB-1925W projector. When pressing power on, after few seconds the fans started to blow at full speed and 3 red leds started flashing. That is an internal error according to the manual. So i ordered a new ballast board from China. After i changed the ballast everything worked fine for a few hours. Then it started to turn off the lamp after 3 minutes or so and blink the leds again. Yesterday i watched two full length movies with no problems, today it won't light up at all. The lamp is an original spare with only 200 hours in the counter. There is no dust anywhere and all the fans work fine. Could the Chinese ballast been faulty or is there some other fault that could cause this behavior or make ballast boards burn?Seppo

author: Kjelt
author_rank: Super Contributor
timestamp: December 09, 2017, 11:13:21 pm
content: It all depends on how the ballast was designed.If it has a microcontroller and is dedicated for a certain lamp and that is not the same type as the one in the projector this could well be the case that it is a mismatch and cause you're issues.AFAIK Epson manufactures their own lamps and drivers.

author: Seppo
author_rank: Newbie
timestamp: December 10, 2017, 06:38:33 pm
content: The lamp is an original spare (no Epson logo on it), and was bought a year a go for 570 euros. The original ballast and the replacement are both built by TDK.

author: Kjelt
author_rank: Super Contributor
timestamp: December 10, 2017, 10:48:56 pm
content: Quote from: Seppo on December 10, 2017, 06:38:33 pmAre they the same, same partnr? If yes, I am out of ideas, original lamp, original driver, should work
Bimetal temperature switch replacement on inverter arc welder machine - Page 1
Forum section: electronics / repair

author: nuno
author_rank: Frequent Contributor
timestamp: December 10, 2017, 07:49:31 pm
content: Hello all,I have an inverter arc welder which turns on but once starting to weld it won't push current/enough current out. In a 1st glance, there's a BR-B2D 85ºC thermal switch stuck open, I guess that could be the sole reason (already checked output connectors and such for deficient electrical connections). Problem is I can't find a replacement except in alibaba at a 1000 MOQ (https://rtsensor.en.alibaba.com/product/60499753078-803502219/BR_B2D_50C_AC_Bimetal_Thermal_Protector_250V_5A_With_Snap_Action_Disc.html- proper datasheet not found) . On ebay there's lots of KSD9700 series on sale (https://www.nikom.biz/pdf/KSD-9700.pdf), and the only difference I can see is that the hysteresis is a little different, with the KSD closing again at 60ºC+- 15ºC instead of the 55ºC+-15ºC of the original BR-B2D. Would you do the swap? Or would it be safer to use the 80ºC version (at the expense of a maybe a little less inverter working time), which closes again at 55ºC+-15ºC as the BR-B2D? I don't know if this device acts regularly during normal use (no experience with welding nor welding machines) although I suspect it does since the device is self-resets (otherwise I guess they would save some cents and use a thermal fuse).Any comments are appreciated... thanks!
Rohde & Schwarz HMO1212 clock battery poblem SOLVED! - Page 1
Forum section: electronics / repair

author: View[+]Finder
author_rank: Unknown
timestamp: December 09, 2017, 07:37:06 pm
content: This tip is specific to the HMO1202 series, but ya never know . . .I bought a R&S HMO1212 oscilloscope after watching Dave's teardown video back in early 2016 and it has worked without a problem until early November 2017. Then it greeted me with a message that the "clock battery" was depleted or missing. I put that off until I had some free time as the battery replacement needed the case to be opened. So yesterday I set about making the repair. What could be easier? I had followed Dave's Prime Directive: "take it apart!" when the 'scope first arrived, so there was no drama getting the case open and putting in a new battery.The plot thickens . . . The new battery failed after a few minutes. Same thing for another one--this time I checked the voltage first, duh. 3V+ OKClue 1: the 'failed' battery showed less than 2V on removalClue 2: the voltage on the 'failed' battery was increasing while being measuredClue 3: there did not appear to be a drain on the battery when measured with the case open; power on or power offClue 4: ditto using a bench PS as a surrogate for the batteryAt this point I surmised that the problem was not the fault of the oscilloscope and since I had 'load-tested' the batteries, not their fault either. So I cleaned the battery and the contacts with IPA and consigned myself to setting the date and time each time I used the 'scope.Then, as I was putting the case back on the 'scope, I noticed through one of the vent-slots a piece of fabric brush against the visible side of the battery. The fabric had been glued inside the case, but a section near the vents had pulled loose.What's that 'fabric' stuff and why is it in there?What do you think I measured with my ohm-meter with probes on the 'fabric'?I'll leave the solution on this thread later today . . .

author: ealex
author_rank: Frequent Contributor
timestamp: December 09, 2017, 08:18:34 pm
content: was it a part of a RF gasket (conductive) ?

author: View[+]Finder
author_rank: Unknown
timestamp: December 09, 2017, 08:52:20 pm
content: Close, so close . . .Conductive it was, yes. Looked like cloth; measured less than one ohm.Not an RF gasket--it covers all the inside back of the case--I'm thinking a Faraday cage.I glued it back in place, so no more drain on the coin-cell battery. When it was loose, it shorted the + side of the coin cell to ground, etc. Why did it come loose? The only thing I can think of was the 'scope was on for an extended time during the Summer and then off for nearly two months.Hello, Rohde & Schwarz: you might want to look into this . . ..
Weller whs40 stick swap - Page 1
Forum section: electronics / repair

author: NiaDebesis
author_rank: Frequent Contributor
timestamp: December 08, 2017, 08:54:36 pm
content: HelloI don't know if is stupid to think about that idea..but I am pretty happy with my whs40..is good for small soldering works..but the stick is almos gone..the screw that tightend up the tip is gone, as the connector (crappy as fu**) so I am thinking to get a jbc stick (I can take one for 30/40 euros, against the 90!! For the original stick) and direct solder the wires of the stick on the pcbI think that it should be fine, that can be an idea?Edit: or find a 4 poles connetor to fix on the case of the soldering station

author: Bashstreet
author_rank: Frequent Contributor
timestamp: December 09, 2017, 01:51:55 am
content: Or get new iron with the 5 pin 180% connector... plug in and your off.

author: NiaDebesis
author_rank: Frequent Contributor
timestamp: December 09, 2017, 06:13:32 am
content: It's 3 pin plus the guide of the connector that is the ground4 pin connector, and I didn't find itAnd I think that the two iron's use diffrent termocouples..so I don't think that it can be possibile, today Ill try to open the soldering station and see whats inside

author: Bashstreet
author_rank: Frequent Contributor
timestamp: December 09, 2017, 08:00:22 am
content: Quote from: NiaDebesis on December 09, 2017, 06:13:32 amAh you have the analogue 4 pin model.Nice way to force customers to stick with their over priced replacements .

author: NiaDebesis
author_rank: Frequent Contributor
timestamp: December 09, 2017, 08:08:17 am
content: Yup, nothing that I can doProbably Ill buy a WS51 usedA decent soldering station

author: Bashstreet
author_rank: Frequent Contributor
timestamp: December 09, 2017, 08:18:42 am
content: Quote from: NiaDebesis on December 09, 2017, 08:08:17 amWell i personally prefer Hakko + some clonesReplacements tips etc are easy to get and cheap (depending what quality stuff you want)Weller makes some nice irons but like you noticed they do tend to like keep their customers forced into their productsWhat is fine if you can afford it.

author: NiaDebesis
author_rank: Frequent Contributor
timestamp: December 09, 2017, 09:29:29 am
content: Thinked about the ws51 because there is an onverflow of the in ebay in this moment, and I can get one for 80 bucks (include the "pro" stand) but without the stick, and the stick for the ws51 cost..around 100buck maybe?

author: NiaDebesis
author_rank: Frequent Contributor
timestamp: December 09, 2017, 09:51:12 am
content: The stick Weller PES51 is compatible with the wsd50 station?
mackie ampifier - Page 1
Forum section: electronics / repair

author: nikkos
author_rank: Newbie
timestamp: December 09, 2017, 02:50:59 pm
content: hi does anyone experienced mackie hd 1221 repair?

author: OmegaHyperion
author_rank: Contributor
timestamp: December 09, 2017, 03:01:40 pm
content: i don't have experience with that amp in particular, but i could see if i can help regardless. i have fixed a few amps over the years after all.More information about the problem would be nice though. Also, do you have a schematic for the amp?

author: Bashstreet
author_rank: Frequent Contributor
timestamp: December 09, 2017, 06:37:57 pm
content: Quote from: OmegaHyperion on December 09, 2017, 03:01:40 pmYeah more information could be useful as there are not many AMP-psychic's around.
VOLTCRAFT VC850 no measurement - Page 1
Forum section: electronics / repair

author: beyma
author_rank: Newbie
timestamp: December 08, 2017, 10:17:37 pm
content: HelloThe meter is based on the FS9922-DMM4 system and a large number of 062C opamp, one AD737J and HEF4070.The WARNING message keeps flashing all the time and displays only zero - no measurement. On the inputs after setting to OHMY there is a voltage of about 1.4V, that is, the system probably works from the input to the switch.Due to the large amount of OPAMPs, I do not know how to do it, and it would be useful for me to get a grip on it, or someone who has already processed such a topic or meter.I greet all readers and thank you for all the help.WitamMiernik zbudowany jest na uk?adzie FS9922-DMM4 oraz du?ej ilo?ci opamp 062C, jednego AD737J i HEF4070.W mierniku ca?y czas miga napis WARNING oraz wy?wietla same zera - brak jakiegokolwiek pomiaru. Na wej?ciach po ustawieniu na OHMY jest napi?cie ok 1.4V czyli od wej?cia do prze??cznika uk?ad chyba dzia?a.Ze wzgl?du na du?? ilo?? OPAMPów troszk? nie wiem jak si? za to zabra? i w?a?nie przyda? by mi si? schemat by to ogarn?? b?d? kogo? kto ju? przerabia? taki temat czy miernik.Pozdrawiam wszystkich czytaj?cych i za wszelk? pomoc dzi?kuj?.
Agilent 3458A ERRSTR 209, HARDWARE FAILURE - Page 1
Forum section: electronics / repair

author: michaelrusseau
author_rank: Newbie
timestamp: December 08, 2017, 01:49:42 pm
content: I have an Agilent 3458A with an ERRSTR 209, HARDWARE FAILURE -- TIMEOUT: UNABLE TO READ A/D: 219 and 114, STSTEM ERROR -- multislope rundown convergence. It is intermittent. I had replaced the A/C board because it had burned up components and now have these error. Elsewhere on this forum it looks like others suspected the A/D Converter and Inguard Logic A3 board but could it be a bad new A/C board?

author: TiN
author_rank: Super Contributor
timestamp: December 08, 2017, 02:26:28 pm
content: Ouch. About 95% chance it's the bad A3 ADC board. You can try to set NPLC 0.001, while in DCV mode.Meter may read the voltage in such case, which directs to ADC issue once again.Perhapsmy past experiencecan be helpful for you.

author: Kleinstein
author_rank: Super Contributor
timestamp: December 08, 2017, 08:26:10 pm
content: Besides ADC failure, it could still be a problem with the fiber connection or the µC.The nasty ADC failure (hybrid ASIC) usually also leads to significant drift in the CAL72 value. So if the meter is still working good enough to get cal72 values, one could check for drift here - with a bad ADC it only take hours to see the drift. Large drift here would be a very strong indication for serious ADC trouble.
IBM server power unit now bricked - Page 1
Forum section: electronics / repair

author: najrao
author_rank: Regular Contributor
timestamp: December 07, 2017, 01:47:06 pm
content: I attach three pictures of the animal I picked up in apparently perfect serviceable condition. Though I am moderately good at deciphering dc power supplies, this very high power unit has left me baffled for a long time. If I can get it going, I can put it to good use, especially the 3.3/5V 150A output. There is no data forthcoming from IBM websites.I can feed it at 350V dc from external PFC unit.Obviously, no connectors are available, and I have to devise other ways, but that has not deterred me in the past.I did do some sort of pinout identification, but the problem is finding what will 'enable' the output.I would be grateful for any leads.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 07, 2017, 06:04:39 pm
content: there is a forum for server powersupplies, dont recall the name, you can find bunch of psu pinouts there, and get some helpNormally you should have a 5vdc standby supply (constant voltage)Sometime i did find the startup pin by adding a 4.7k - 10 k resistor in series with the 5vdc standy supply, and the psu should/would start, unless there is a voltage to ground startup pin

author: Nusa
author_rank: Super Contributor
timestamp: December 07, 2017, 06:30:02 pm
content: Quote from: coromonadalix on December 07, 2017, 06:04:39 pmYou're probably thinking of the rcgroups.com forum, that has reported on a lot of successful server supply pinouts and conversions usually for battery charging purposes. I've got some on my own shelves: 12V 40A DC supplies that cost me a whole $5 each to buy and convert.It's not going to help in this case as this isn't the kind of supply that's useful to the RC industry. It's a DC-DC converter, expecting 350V DC as input. A supply voltage that makes sense in data centers, but rarely out in the real world.The only people that are going to know much about this are the people that actually used them. And those people generally had the correct cables and backplane slots.

author: najrao
author_rank: Regular Contributor
timestamp: December 08, 2017, 03:44:15 am
content: RC groups had no answer.Frankly, I have not gone enough deep into it yet, and will try to locate any Vsb and start up pins. There are three jacks, two at the front, with 32 pins in all. The main power jack seems to be all outputs.I attach a picture of the innards, if that helps.

author: Bashstreet
author_rank: Frequent Contributor
timestamp: December 08, 2017, 07:43:48 pm
content: Do you even know for sure there is pin out for PS_ON .Why have you not tested the pins for power ?As coromonadalix said there must be open line for 5v or or similar to offer the PS_ON
Coupla 12V Power Supply Repair Questions - Page 1
Forum section: electronics / repair

author: martinator
author_rank: Contributor
timestamp: December 01, 2017, 11:26:07 am
content: Hi,I'm repairing a 12v power supply.Looks like a transistor shorted made a capacitor go open circuit and killed one diode in the bridge rectifier.Anyone know a replacement for the 2SK3115?They are a little pricey on ebay and quality is unknown so I ordered a STP6NK60ZFP as a replacement.Also, some glue used to hold in components looks rather cooked. If I measure across it with a multimeter I get about 120k ohms. That's not good is it? This is in the vicinity of the blown transistor. I will scrape it off.CheersMartin

author: martinator
author_rank: Contributor
timestamp: December 11, 2017, 03:33:49 pm
content: The STP6NK60ZFP seems to work as a replacement for the 2SK3115. I also needed a new UC3842AN a 68uf capacitor and a 1N4728A.