hybridfree/eevblog-posts huggingface dataset:
(SOLVED) Electro / Manson 9602 obliterated part ID request - Page 1
Forum section: electronics / repair

author: Majorstrain
author_rank: Contributor
timestamp: February 18, 2018, 01:02:02 pm
content: Hi all,I've got a Electro / Manson 9602 PSU (1-30V 30A) out for the count at the moment.I would like help identifying U2 on the board closest to the front. The device is in a 6 pin TO-220 format.If any of you have the same unit, would you mind taking the cover off and letting me know the part number of U2.Cheers,Phil

author: Chris56000
author_rank: Frequent Contributor
timestamp: February 18, 2018, 03:43:15 pm
content: Hi!There's enough of it left for me to give an intelligent "guess" at it - I can see the first part of a "Power Innovations" logo and part of "TO", so you're looking at a "Topswitch" integrated MOSFET/Control IC power device, TOP247Y or similar!If you can remove the PCB with the device and post a clear pic of both copper (print) and the component-sides I'll have a browse in P.I'ssite and see if I can get you a more exact identification!The serial nos of these "TopSwitch" devices basically go up in ascending power ratings, they are characterised according to power O/P rather than V/I ratings - a six-pin device rated for 230V mains at about 100W max. O/P power should do for your unit - I suspect it provides the standby supply!Chris Williams

author: seronday
author_rank: Regular Contributor
timestamp: February 18, 2018, 11:18:37 pm
content: Attached is some info on the Manson SPS9600 15V 60A power supply.Most of the circuit should be the same as your power supply.Regards.

author: Majorstrain
author_rank: Contributor
timestamp: February 19, 2018, 12:31:56 pm
content: Thanks Chris56000 and seronday.The SPS9600 power factor correction and auxiliary power supply board is the same in both my 30V 30A unit as well as the 15V 60A unit that is in the PDF.U2 is specified as a TOP243Y. I've got a couple on order.ZD2 was also faulty. (5.6V zener)The circuit diagram will be very useful when I check for more issues around that area.Thanks again for you fast responses guys.Cheers,Phil

author: wictor
author_rank: Regular Contributor
timestamp: February 20, 2018, 07:27:38 am
content: Hi,I had problem with VOLTCRAFT SPS 1560 PFC, which is similar Manson model as yours, but 60A. The whole PFC was toasted, but the supply seemed to work fine. I noticed the problem only, when I opened the unit.
Sony 50" TV KDL-50W800B LED display issue - Page 1
Forum section: electronics / repair

author: Shock
author_rank: Super Contributor
timestamp: February 19, 2018, 04:55:42 am
content: Taking a look at this LED TV.Fault:Responds to power on from standby.Remote and audio seems to work.When turning on with remote a thick horizontal white bar appears.After a few seconds this bar seems to compress and then blue vertical lines are seen.Troubleshooting:Cleaned and reseated the connectors and boards.Inspected the connectors on cables, they look in good condition.No change, wondering where to start on this one.Repair and service manuals.https://www.manualslib.com/download/1087617/Sony-Kdl-50w800b.htmlhttps://www.manualslib.com/download/1258726/Sony-Kdl-32w700b.html

author: HecticZA
author_rank: Contributor
timestamp: February 19, 2018, 05:14:07 am
content: Not the same, but I wonder if this process might be of use for you?https://youtu.be/u1aA2TIKs4MSent from my SM-N950F using Tapatalk

author: Shock
author_rank: Super Contributor
timestamp: February 19, 2018, 05:51:57 am
content: Yeah it sort of looks like there may be an image there messed up.I'll have to pull it apart again and position it better to get at the Tcon, it's currently buried under the BAX board (main/graphics).

author: Shock
author_rank: Super Contributor
timestamp: February 19, 2018, 06:05:23 am
content: Well it's half working.

author: Shock
author_rank: Super Contributor
timestamp: February 19, 2018, 06:22:58 am
content: I swapped the Tcon cables over as well and checked they were both functional and the fault follows the left side of the Tcon (which is the right panel side). I'm taking bets, hints and predictions at this stage.

author: Shock
author_rank: Super Contributor
timestamp: February 19, 2018, 01:26:03 pm
content: Going to take some measurements tomorrow and compare the two sides.Want to deduce if it's somewhere on the Tcon causing the issue or on the buffer boards (painful).Has anyone got any service experience or info on what measurements I should be seeing on this specific Tcon? Sonys number of this board is 5550T20C01.Many test points but nothing very descriptive.

author: Shock
author_rank: Super Contributor
timestamp: February 20, 2018, 06:54:02 am
content: Checked the two identical sets of 9 HC/LC/ST test points on the left and right Tcon cables and the larger 14 VGA test points. When the panel is running with the working side only connected or no cables connected measurements are shown as below which looks pretty sane.When the non working side is connected by itself or with the both cables connected, most of the test points voltages are all over the place.So I'll go out on a limb here and say at this point it feels like it's not a problem on the Tcon board and feeling like one side of the vertical buffer board on the panel.(readings approximated)HC6 2.1vHC5 2.1vHC4 2.1vHC3 2.1VHC2 2.1vHC1 2.1vLC2 29v and -9v (alternating)LC1 29v and -9v (alternating)ST1 -9vVGA1 14vVGA2 14vVGA3 12vVGA4 12vVGA5 10vVGA6 9vVGA7 9vVGA8 6.5vVGA9 6.2vVGA10 5.1vVGA11 4vVGA12 2.5vVGA12 0.5vVGA14 0.3v
Broken ODAC - Page 1
Forum section: electronics / repair

author: tsegers
author_rank: Newbie
timestamp: February 19, 2018, 10:32:57 pm
content: So I've got this headphone DAC/AMP combo called O2/ODAC. After waking up this morning it suddenly heard crackling on the left channel. I ripped the thing apart and took some measurements  on pins of the DAC chip . There is noise of exactly half the frequency of the 352KHz "charge pump circuit" referenced in the datasheet . Does that ring any bells with anyone?The thing is, the crackling is audible. This means it's not the 176KHz noise I'm actually hearing. But this noise is only present on the channel I can hear the crackling on.If some passive component is at fault, I can simply swap it. If it's the DAC that's ruined, I have to trash the board. That would not be the end of the world, but I'd be a shame to trash something only a 10ct part away from functioning. Any ideas or input would be greatly appreciated. Charge pump Noise Boardhttps://myl8test.files.wordpress.com/2013/05/es9023-datasheet.pdf
Warped Sifam meters - Page 1
Forum section: electronics / repair

author: artag
author_rank: Super Contributor
timestamp: February 18, 2018, 01:45:42 am
content: I'm repairing an old Farnell power supply in which neither of the large Sifam meters on the front panel were working.On investigating, I found that the black cover over the coil mechanism was warped in such a way that it was stopping the needle moving. Both meters were warped in almost exactly the same way.This would suggest overheating, but the rest of the meter casing looks perfect. However, those parts could be different plastics : I think a phenol plastic for the main casing and acrylic for the cover 'glass', while the black cosmetic piece is probably polystyrene.Has anyone else experienced this problem ? Is it likely to be due to temperature, or age ?
Re-capping a Tektronix 422, and silver solder - Page 1
Forum section: electronics / repair

author: lordvader88
author_rank: Frequent Contributor
timestamp: February 17, 2018, 03:31:33 am
content: I got this off ebay with no cord and I soldered on a 3-pin plug and turned it on for 5,10s 2-3 times I guess, maybe 30s-60s on the last time.This was December, I did see some green trace for some moment on it, so it's alive for the most part. If irc the trace disappeared and so I turned it off. And then I know this for sure, it has the mains coming into a fuse holder and I had turned it so that it was shorting out on the power switch. And so it that was the last time it worked.I have ordered and have most of the replacement electro caps, but I still don't have the proper solder.The traces and even big plated parts of the PCB (the power section, never cracked the other 1/2 yet) have gold traces. So I guess its gold. I have the schematics/manual, and it calls for 3% silver solder.

author: xwarp
author_rank: Frequent Contributor
timestamp: February 18, 2018, 12:29:16 am
content: The requirement for the silver solder is for use on the ceramic stand offs where there are soldered connections. Every where else, standard solder is fine.I have a 422 also, but have the AC and the DC supple for it. Good little scope.
HP 437 - 438 and HP8484A + Cable Wont Zero, How to verify HP437 - 438 will zero - Page 1
Forum section: electronics / repair

author: Hyqtech
author_rank: Newbie
timestamp: February 17, 2018, 03:25:26 pm
content: Been having a issue with a HP437B, HP8484A and cable not zeroing. Been chasing signals for a while and found that the signal ground pin E on the cable is broken off at one end as well as my power sensor diode is bad. Can't find the broken off pin and it's not stuck in the 12 socket DIN connector.I found a way to verify the HP437B actually reads a signal and zeroes out. Press the Preset button then press Enter. Using 1/8 watts resistors stick a 10K resistor between pin K and J in the DIN connector on the meter. This tells the meter that a pseudo HP8484A power sensor is connected to the meter. Then place a 1K 1/8watt resistor between pin L and C on the meter which is sampled output and feedback return. You should observe a very low -60 to -80dbm. Press the Zero Key and the meter will zero with a reading close to -100dbm when it is complete. Then remove and replace the 1K resistor between Pin C and Pin L which is sampled output and auto zero and you should read about -70dbm. At least you now know the meter can zero.
Add Opt 001 to Agilent 33220A ? - Page 1
Forum section: electronics / repair

author: JohnPi
author_rank: Regular Contributor
timestamp: February 17, 2018, 11:15:30 pm
content: I scooped an Agilent 33220A locally, but it doesn't have the external reference input capability -- those BNC holes at the rear are dummies.Does anyone know if manually adding BNCs is all that is needed ? -- are the circuits associated with it (schematic shows a coupling transformer, and some detection circuits) populated on a non-Opt 001 board ? Any photos of the inside ?

author: JohnPi
author_rank: Regular Contributor
timestamp: February 18, 2018, 12:11:45 am
content: Never mind -- I see in the service manual that this option adds another small board inside the instrument.
Westbond 7700A Repair - Page 1
Forum section: electronics / repair

author: dbinokc
author_rank: Contributor
timestamp: February 17, 2018, 01:10:51 am
content: I recently purchased a Westbond 7700A from ebay. I only paid $250 for it, so I was not expecting much. Unfortunately the seller did a horrible job packing the machine and it got bounced around pretty badly. So in addition to the big part I had lots of little parts scattered around in the box.One item in particular is a large single bearing ball that was rolling around in the box. I know it is part of the machine because it is listed as a part in the 7700A manual I have. The question is where does it go. If someone has access to this model of machine perhaps they could take some close up pictures of where it is supposed to go. Close up pictures all around would be quite helpful as I try to piece this back to together.
Wolfvision Eye-12 - Page 1
Forum section: electronics / repair

author: Docholiday
author_rank: Regular Contributor
timestamp: February 16, 2018, 06:19:38 pm
content: Looking for a schematic for the Wolfvision Eye-12. They are manufactured in Austria if that helps any. I contacted Wolfvision in USA but they were very, very rude when I asked them if I could get a schematic for a product recently retired.Thank You,Nicholas
Auto-off on digital 200kg scales not working - Page 1
Forum section: electronics / repair

author: lordvader88
author_rank: Frequent Contributor
timestamp: February 15, 2018, 02:11:51 pm
content: What in the world would cause that? I think it has some hidden little IC like a calculator. Where as it used to auto-off after maybe 1-2 min (I can't remember) now it will sometimes stay on for days until I take out a battery, and single beep once and a while. Other times it does shut off quick I think. Or sometimes hours laterI should pay attention to it , but...

author: Muxr
author_rank: Super Contributor
timestamp: February 15, 2018, 02:32:43 pm
content: Maybe it's a poor implementation, where it monitors the scale value and if the value doesn't change for awhile it auto shuts off. But ADCs sometimes like to flutter between numbers like your DMM, and that could be interfering with it. Try zeroing the scale and see if it auto shots off.
Help identifying PCB pushbutton - Page 1
Forum section: electronics / repair

author: markav2
author_rank: Contributor
timestamp: February 14, 2018, 06:55:02 pm
content: Good afternoon everyone,Longtime follower and first-time poster.I'm working on some old obsolete quality inspection test equipment for the automotive industry. Having an issue finding out who the manufacturer of the buttons is for this product. I've done some other repairs on other models and I've always been able to find different style buttons. This time I'm really having an issue and I hope someone will recognize the logo. Very difficult to get a good image so I put old paint so that it hopefully it will be visible.Thank you for any help in advanceAll photos:https://www.dropbox.com/sh/a5l3pxd7kvtvzq5/AAC0NcX61FJ49h4h7G_py97-a?dl=0

author: pieman103021
author_rank: Contributor
timestamp: February 14, 2018, 06:59:39 pm
content: I think you forgot the image

author: ataradov
author_rank: Super Contributor
timestamp: February 14, 2018, 07:54:05 pm
content: Looks like a generic 12x12mm push button. There are lots of them on eBay, but they all seem to have a post for the cap.Something like thishttps://www.ebay.com/itm/10x-Momentary-Tact-Tactile-Push-Button-Switch-12-x-12mm-x-8mm-4P-4-Pin-DIP-Cap/281341214785?epid=1838190563cam probably be modified, if you don't find exact match.Actually here are the same buttons, but with the style of cap you wanthttps://www.ebay.com/itm/45Pcs-12-x-12mm-Tactile-Push-Button-Switch-Momentary-Tact/311449272434?epid=1947195580&hash=item4883d2c072:g:ZHEAAOSwH2VaOYun

author: markav2
author_rank: Contributor
timestamp: February 14, 2018, 07:59:42 pm
content: Yes, it is a 12 x 12 but as you notice there are two parts. The top is the illumination that also has a filter that goes over it along with different colored lens caps. Pretty sure I can get any switch it's just the rest of it I really need. That's why I was hoping to find the manufacturer. The control panel was produced in Japan and all the other switches that I've replaced on different components for this equipment all originated there. But the logo at the bottom of the switch I cannot seem to find anywhere.Thank you

author: floobydust
author_rank: Super Contributor
timestamp: February 15, 2018, 06:09:03 am
content: I see the popular 12mm pushbutton switch Omron B3W-4000 series, copied across industry. Your logo FC or FE didn't ring a bell.The quad-LED light or button looks maybeNKK SwitchestheirJL seriesOmronmight make them but their illuminated tactiles are big, ugly.e-switchmight be another to check.
Tektronix 2215 bad switch contact - Page 1
Forum section: electronics / repair

author: lordvader88
author_rank: Frequent Contributor
timestamp: February 15, 2018, 01:50:56 am
content: I got this used and I'm happy with it, seems to work pretty good for what I've tried, but this is only my 2nd benchtop scope and 1st analog 1.The power switch release/spring mechanism was broke so I had to hack a solution for that.Now the CH1 coupling switch is very loose and so makes poor contact sometimes. Also the SEC/DIV assembly comes loose and makes bad contact going from 0.5ms to 0.2ms, and I just get the beam dot or vertical line sweeping across the screen slowly.Anyone familiar with the that 1980s ear Tek stuff? I don't want to pull it apart just to find its some sealed/welded closed switch that I can't open up to clean. I don't have contact cleaner either.I have the schematics, hope the s/div switch its too complicated or enclosed, I don't have many tools.
Farnell l30 power supply capacitor replacement - Page 1
Forum section: electronics / repair

author: Robmanser11
author_rank: Newbie
timestamp: February 15, 2018, 03:51:07 pm
content: HiI am new to electronics, and my first repair project is the above power supply.It should go up to 30v, but when I powered it up, I was getting about 2.5vLooking inside one of the large caps had burst. The part number is hunts 3132a hya.The circuit diagram says this is a2200uf cap at 63 v. Can anyone suggest a suitable replacement? They are connected in parellel, about 40mm dia and, say 75mm longHope someone here can help, so I can have my first successful repair.......

author: Vic20
author_rank: Contributor
timestamp: February 17, 2018, 09:01:56 am
content: If it is a power supply I think that any 2200uF @63V or more would do.If there are several like it in parallel, I think that you can take it out and test the supply without it.Probably at low loads the circuit will work ok without it as the other caps will still work and you only will see an overall lower total capacitance.The faulty cap probably is draining the current, but who knows? Perhaps it is not the only faulty component.As this is @63V I undestand that it is in the output side of the supply.
Linn Sizmik 10.45 Sub Amp - Page 1
Forum section: electronics / repair

author: Birstall
author_rank: Contributor
timestamp: February 17, 2018, 04:52:51 pm
content: I have just lost the amplifier and there is no replacement available from Linn. Has anyone had experience in repairing one?

author: dashpuppy
author_rank: Regular Contributor
timestamp: February 17, 2018, 05:28:41 pm
content: Any pics ?Is it all covered in glue inside the amp module ?

author: Birstall
author_rank: Contributor
timestamp: February 19, 2018, 06:42:15 pm
content: I haven't looked yet, I just wondered if anyone had any experience before I started opening it up.I spoke to the Linn reps in the US and they are no longer supported.According to the the Linn forum the Majik 126 module will work.If its just cap replacement I'm up for that but if the PCB is blown I am in for some expense.
Replacing the infamous Schaffner mains filter on an HP 8561A Spectrum Analyzer - Page 1
Forum section: electronics / repair

author: SMB784
author_rank: Frequent Contributor
timestamp: February 13, 2018, 02:06:30 am
content: Howdy everyone, I am looking to replace the Schaffner FN 365-4/01 mains filter on my HP 8561A 6.5 GHz Spectrum Analyzer, as these are prone to spectacular failures.I need some help identifying which modern mains filter I should replace it with. I have attached an image of the offending mains filter. I have found this replacement filter, theSchaffner FN9260A-4-06, and I am hoping that it has the correct specifications, but I was hoping for a bit of help trying to ascertain whether or not it has the same specs.Anyone have any ideas?

author: floobydust
author_rank: Super Contributor
timestamp: February 13, 2018, 02:31:22 am
content: The old filter shows one-stage with values of 0.8mH, 15nF X-cap, 2.2nF Y-caps, 4A.The Y-caps are much smaller in your pick, and the X-caps much larger:FN9260-4-06 is 1mH, 100nF X-cap, 0.47nF Y-caps, 4A and two fuses?FN261-4-06 is 1mH, 100nF X-cap, 2.2nF Y-caps, 4A and only one fuse.

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 13, 2018, 03:52:58 am
content: It has been a long time since I last opened one, but I recall that by desoldering the ground terminal, the cover slides off and then you can just replace the caps.

author: EHT
author_rank: Frequent Contributor
timestamp: February 13, 2018, 09:14:08 am
content: I used the following one to replace the filter on my 3457A. It needed a bit of research to find one small enough. I also looked for ones that had some kind of credible fire protection rating. Note that there is a snap-in model and a screw-in model. I accidentally ordered the snap-in as Farnell have the picture of the screw-in on this one. However, it fitted in anyway.5110-0343-1 - IEC Filter, 47 nF, 250 V, IEC, Mains, 3 A, Quick Connect, 2.5 mHManufacturer: SCHURTERManufacturer Part No: 5110-0343-1http://uk.farnell.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&langId=44&urlRequestType=Base&partNumber=1125792&storeId=10151http://www.farnell.com/datasheets/1910888.pdf?_ga=2.65374699.438245235.1518512638-2018945104.1508796824

author: SMB784
author_rank: Frequent Contributor
timestamp: February 14, 2018, 12:26:54 am
content: Quote from: floobydust on February 13, 2018, 02:31:22 amThank you for the advice, it is very helpful. Will the near order of magnitude difference in the x capacitor capacitance between the old model and the new one make any substantive difference in the performance of the power supply, in your estimation?

author: floobydust
author_rank: Super Contributor
timestamp: February 14, 2018, 04:07:39 am
content: I don't see any penalty having a larger value X-capacitor.I would not use a smaller 0.47nF Y-caps, I would stay with 2.2nF as I find that is effective.Down the rabbit hole, theFN332has the same component values (small 15nF X-cap) as the FN365; comparing(differential)curves to the FN9260, I like the FN261 but not a huge difference.
E3610A voltage output drifting.... - Page 1
Forum section: electronics / repair

author: jasonbrent
author_rank: Regular Contributor
timestamp: February 13, 2018, 06:08:30 pm
content: Folk,I've had an E3610A sitting on my shelf for the last few years that I used on occasion. The voltage from it was never exactly precise (e.g. 4.52volts on the display to get 4.5volts output), but it was stable. Almost no drift, at least not anything measurable with any equipment I had in the past.I've now got a Keithley 2015 with a recent calibration, so I decided to correct that reading vs. output voltage difference. As best I can tell, I've followed the voltage calibration method from the manual (didn't calibrate current since I don't have a 0.1% 0.1Ohm 10W resistor as it prescribes).Now when I set it to 15Volts, it's 15.000xx on the keithley, 1.00 volts is 1.000xx on the keithley... and it's stable. The last couple of least significant digits end up with no visible fluctuation....However, if I let it sit there a few hours, I'll come back to what was 4.00 volts output and displayed as 4.11 volts output and displayed... way out of drift specs.Before I mucked with the 10turn calibration points in it, the voltage was off, but didn't drift. now the voltage is on, but drifts a lot.Any thoughts on how to correct it? Any other options than a 0.1% 0.1Ohm 10W resistor for calibrating current? (the closest matching resistor to the manual's recommendation I found was ~$80 USD on digikey!).Thank you,Jason

author: Samogon
author_rank: Frequent Contributor
timestamp: February 13, 2018, 06:44:41 pm
content: You can use any resistor with 10w or more even use copper wire like 12-16Ga and measure it with your keithley meter to be exact.But not necessarily same value, it can be 1 Ohm just use Ohm’s law to calculate value when doing calibration and put this value into power supply display.

author: jasonbrent
author_rank: Regular Contributor
timestamp: February 13, 2018, 07:39:06 pm
content: Quote from: Samogon on February 13, 2018, 06:44:41 pmMakes sense... I can get away with using a spare coil made from resistance wire as I am sure I can sink 10 watts into it for a while. Thank you.Sent from my SM-N950U using Tapatalk
CyberPower UPS - Page 1
Forum section: electronics / repair

author: metrologist
author_rank: Super Contributor
timestamp: February 13, 2018, 07:33:30 pm
content: I've had a cyberpower UPS in service for a few years. About a year ago, it beeped and shut down, powered up for a few seconds, shut down, and... I don't recall exactly what happened, but that problem seemed to just go away. Well, it happened again and this time after a few power cycles, my BIOS got corrupted...This time I turned off the UPS and waited a minute or so - unplugged the devices - and powered it back up. I noticed the battery indicator was full while this thing was throwing its tantrum, but when I got it powered back up stable, the batter indicator was 3%. I let it sit for an hour or so and the battery was full again.I plugged the devices into the surge ports (not BU battery) and it has been working fine for a couple weeks.I plan to connect a couple hundred watt lights to the BU battery output and determine the capacity.I'm sure most will suspect the battery and, if so, this operating mode seems like a horrendous design flaw since the power did not go out.On the chance that the battery delivers, any idea what I should look for?
VOLTCRAFT GDM704 - Page 1
Forum section: electronics / repair

author: lionelkjh
author_rank: Frequent Contributor
timestamp: February 11, 2018, 08:20:18 am
content: Hello everyone! I have a high-end multimeter VOLTCRAFT GDM 704. It is functional, but I found that the latter quickly discharges the batteries (even with new batteries). It consumes 150mA when it works. Could someone tell me if this measured consumption is normal or excessive ?? Thanks for your help!

author: lionelkjh
author_rank: Frequent Contributor
timestamp: February 12, 2018, 05:11:43 pm
content: help!

author: retiredcaps
author_rank: Super Contributor
timestamp: February 12, 2018, 08:20:13 pm
content: Dismal battery life seems normal for this model. Seehttps://www.eevblog.com/forum/chat/which-multimeter-to-buy/msg8339/#msg8339Quote from: x0170 on June 16, 2010, 10:42:53 am

author: lionelkjh
author_rank: Frequent Contributor
timestamp: February 13, 2018, 07:33:12 am
content: Hello; weird, because even when the batteries are discharged, the battery indicator indicates that the battery is full, and no indication "low battery" .... What is the explanation ??
Successfully repaired high-pressure differential probe - Page 1
Forum section: electronics / repair

author: pzil
author_rank: Newbie
timestamp: February 14, 2018, 02:48:49 pm
content: Hi guysI bought a bad high voltage differential probe?Yesterday I decided to repair it?I spent half day, found the fault?

author: HighVoltage
author_rank: Super Contributor
timestamp: February 14, 2018, 03:05:53 pm
content: So, what was the fault?

author: Armadillo
author_rank: Super Contributor
timestamp: February 14, 2018, 03:06:25 pm
content: This is a poor copy of the original.The high voltage input section should be segregated from the differential input section.It don't even have isolation slots cut into the board.But good repair from you, though.Appreciate your sharing but it would be best for you to also relate the faults and the repair, yeah.

author: pzil
author_rank: Newbie
timestamp: February 14, 2018, 03:42:48 pm
content: This is Yokogawa's product ?But when I teardown it?I was surprised that it is OEM products made in Taiwan?Now let's talk about what is wrong with this product:When the power switch is turned on, the power LED and overrange LED are ON?So I measured the output (BNC) voltage value?voltage value is only 0.018V ?I suspect there may be a problem with the circuit's power supply?I continue to teardown?I found the power supply is a DC / DC circuit, and there is a transformer?I guess the circuit structure (but I can not know the circuit Schematic )?

author: pzil
author_rank: Newbie
timestamp: February 14, 2018, 04:04:42 pm
content: DC / DC circuit works?Transformer input should be PWM?I use an oscilloscope to measure the circuit here?It is found that it is a 0V DC signal level?So I continue to measure the IC's output signal, which is also a 0V DC level?I suspect IC is bad?But I did not teardown IC ?Because I think the IC connected circuit may be bad?So I measure the transistor connected to the transformer?Found that the resistance between the transistor B C is 96 ohms?I suspect the problem is here?So I changed the transistor?After turn on the power again?Measuring transformer input circuit?It is a beautiful PWM signal?overrange Led does not work
Epson Powerlite 3020e video issue - Page 1
Forum section: electronics / repair

author: tibimakai
author_rank: Contributor
timestamp: February 11, 2018, 04:48:16 am
content: I have picked up this projector, from a service center, for $20.I have never worked on a projector before.Everything seems to work, except video on video inputs.What I mean is, that none of the video inputs work.Only one thin horizontal line works, at the top. The image in that line, seems like it is doubled side by side, like a 3D side by side image.Sound works, there are no error lights on.If I put a picture on a USB stick, it shows nicely on the whole screen.So it must be something, with the video processing, that is common to all video inputs.Any help, would be appreciated.Projector, did not come with a remote.I couldn't find a service manual either.

author: tibimakai
author_rank: Contributor
timestamp: February 11, 2018, 05:45:07 am
content: Menu shows as well.

author: tibimakai
author_rank: Contributor
timestamp: February 13, 2018, 03:19:51 am
content: I have started inspecting the board, but I did not see anything obviously wrong.I have also started identifying ICs on the board.Unfortunately, I can't find any info, about most of the ICs. Most likely, they are proprietary Epson Ics.There is a ST FLi32626H (Single-chip enhanced LCD TV controller), Lattice LFXP2-5E-5FTN256C (available at Digikey), 2 x Epson EV0805SA, Epson EV2006XA, EPSON E07140K0B, 2 X IDT V105ADAG/ZA51331J, PANASONIC MN864773AKE (HDMI), TEXAS INSTRUMENTS TMDS261B (2 in 1 HDMI switch).These are some quick phone pictures. In the weekend, I will take some proper ones, outside at sun light and with camera and stand.
repair a battery pack question  - Page 1
Forum section: electronics / repair

author: sub2001zero
author_rank: Contributor
timestamp: February 12, 2018, 10:59:35 pm
content: Hi I am quiet new to electronic repair but, under stand a lot of information. So I have a few question. First off the battery is from a handheld marine transceiver. I bought and found out the battery was no good because the Li-on where zero out with no voltage at all. Original battery capacity was 1150 mah normal voltage 7.4v discharge 5.5v 2 unknown14650 cell so I replace them 14650 Sanyo 7v/5v AA 920 mAh Li-on Flat Top Battery. I made new tabs for the new battery and it was a tight fit get them back in. When it came to re soldering the board i guess one of tabs hit the one diode and short it out. I try looking for one too replace the on that was short out with no luck. I post a picture of the diode. I guess the diode I burn was a Zener Diode. The diode is marked 75 with a gray line on the left side and has a dot above the 5. There was one good 75 diode but have not test the value of it. I know i can test it with a variable power supply a 1k ohm resister and a multimeter and can I you use a clamp on meter to messuare the amperage unknown diode. I guess the board i mess up is a normal Protect PCB Board Balance or am i wrong and if it is can i replace last picture or not. See pictures!

author: sub2001zero
author_rank: Contributor
timestamp: February 12, 2018, 11:02:11 pm
content: picture

author: sub2001zero
author_rank: Contributor
timestamp: February 12, 2018, 11:03:50 pm
content: can the board be replace with the one in picture thanks!

author: KhronX
author_rank: Frequent Contributor
timestamp: February 12, 2018, 11:08:15 pm
content: That could potentially be a 7.5V zener (in a SOD-123 package), but... It would really help if you could manage to lift at least part of the schematic of that board.

author: sub2001zero
author_rank: Contributor
timestamp: February 12, 2018, 11:16:31 pm
content: the battery came from a standard horizon Hx751# on board AP2023 back word RU ST-2ABW9390
Oscilloscope repair - Page 1
Forum section: electronics / repair

author: pzil
author_rank: Newbie
timestamp: February 09, 2018, 04:49:32 am
content: Hi guysI have a Yokogawa oscilloscope DL1740E?But it can not be started?I want to try to repair it?I hope to get some help?thank you

author: rhb
author_rank: Super Contributor
timestamp: February 09, 2018, 04:49:54 pm
content: I'd start by finding the most recent firmware for the device and trying to reinstall it. That will tell you if it is just a boot image corruption problem or an actual device failure.

author: Robmanser11
author_rank: Newbie
timestamp: February 11, 2018, 11:53:03 am
content: HiSorry if I'm in the wrong area, but can anyone please help.I have a 7623a oscilloscope, which I powered up yesterday, stupidly.It is really old, and has been in a shed for ages and was probably damp. When I powered it up, there was a green haze on the display. This was dancing around for a while, but after about a minute, it suddenly just died. Consider me fairly new to electronics,but have a reasonable understanding of the basics. I want to learn a lot more, hence my getting the oscilloscope out.The question I have is, is it worth/possible repairing. . I am happy to have a go. If not, I know they are fairly cheap on eBay, probably 50 - 100. Ifits not worth repairing, I think it may be useful to someone else on here.Hoping someone on here can please help or advise me.

author: anachrocomputer
author_rank: Regular Contributor
timestamp: February 11, 2018, 02:18:41 pm
content: You're in the right area! There are many oscilloscope enthusiasts here who may be able to help you. But you've posted a reply to another query about another type of scope altogether. Far better to start a new topic, and give it a clear and intriguing title. I presume this is a Tektronix 7623A? If so, make sure your title includes "Tektronix 7623A". Tell us as much information as you can about the scope and the fault. Also tell us what test gear and tools you have for the repair (multimeters, soldering gear, other scopes, etc.). With a little more information, you'll get more useful responses.

author: Stray Electron
author_rank: Super Contributor
timestamp: February 11, 2018, 04:55:45 pm
content: I have never seen a Yokogawa service manual in the US. I would contact Yokogawa directly in Japan and see if they can help. The Japanese have been surprisingly helpful to me when I contacted them directly.Does this model use the plug in acquisition modules? Do you have the modules for it? I was considering a DL708 but decided against if because modules were too hard to find and the fact that service information appears to simply not exist.

author: Robmanser11
author_rank: Newbie
timestamp: February 12, 2018, 05:48:42 pm
content: Hi and thank you for responding. Just one question, how do I start a new topic

author: anachrocomputer
author_rank: Regular Contributor
timestamp: February 12, 2018, 08:48:41 pm
content: Go to the main forum page for repair:https://www.eevblog.com/forum/repair/And click on the "New Topic" button near the right-hand side.
34401a front panel reset - Page 1
Forum section: electronics / repair

author: Andrejka
author_rank: Contributor
timestamp: February 10, 2018, 09:16:36 pm
content: Hello everyone,Another lucky owner of non working 34401a;) Popular problem - no display. VFD shows all segments at power on, then goes off. Shift can enable/disable "shift "mark.What I inspected, power voltages are ok without significant ripples, U553 / LM2925T reset line is toggling at 7khz rate, so maybe micro trying to boot, but unsuccessfully. Now I checking communication with front panel, and there is no communcation via serial bus.Can anyone explain how front panel reset works?Several scoping points.IGFPRES signal without FP (referenced to AGND)1. IGFPRES signal with FP connected (referenced to AGND)2. after bypassing C601 (-18V referenced)3. at Q601 base (-18V referenced)4. Q601 collector (-18V referenced)SchematicWhy IGFPRES signal drops significantly after connecting FP?At Q601 collector is always active high level, and why I not see any reset pulses from main CPU?P.S. FP CPU looks like working, there is DISP_SCLK pulses and keyboard scanning also works.Thanks Andrej

author: Samogon
author_rank: Frequent Contributor
timestamp: February 11, 2018, 01:15:22 am
content: I would check if central CPU is working

author: picburner
author_rank: Frequent Contributor
timestamp: February 11, 2018, 04:59:25 pm
content: I would try to connect to the IGFPRES line a 6,8Kohm resistor as load without connecting the FP and I would watch what happens with the oscilloscope.If the signal collapses as in the second picture there could be a problem on the main CPU side.Otherwise I would check C601, CR601 and Q601.

author: Andrejka
author_rank: Contributor
timestamp: February 12, 2018, 03:19:53 am
content: Thanks. Will check.
Fluke 8600A - Page 1
Forum section: electronics / repair

author: GEBevis
author_rank: Newbie
timestamp: February 09, 2018, 08:01:10 am
content: Hi everyone,I have a Fluke 8600A and the display flashes random values and then flashes to the overload display "1.8888" When I select the different ranges the appropriate LED lights in the proper decimal place, and the LED indicating DC, or AC, or OHMs lights up when the different mode buttons are pressed. Due to the way it displays the measured A/D converted DC voltage vs time slope I think it might be problems with the timing in the U4 or U5 and U6 A/D converter circuit. If anyone has any experience with this problem I would very much appreciate your input. Any ideas will be appreciated. I have done a thorough cleaning of all buttons and switches and recapped the old electrolytics in the P/S. All voltages check nominal at all test points. I am now plowing thru the manual to familiarize myself with the operational theory and the block/schematic diagrams.Thanks for any helpGary

author: med6753
author_rank: Super Contributor
timestamp: February 10, 2018, 08:22:11 am
content: I also have an 8600A but I have not experienced the issue you have so unfortunately I can't provide much help. But I would be very interested in what you find for the benefit of "just in case".

author: halexa
author_rank: Regular Contributor
timestamp: February 10, 2018, 10:08:38 am
content: Hi,Try to measure the input resistance on each range/function. To see if something in the input circuit is dodgy.I have a working 8600 unit we can compare the result with.

author: GEBevis
author_rank: Newbie
timestamp: February 10, 2018, 07:58:29 pm
content: I have done some trouble shooting with the manual referring to sections 4-56 to 4-60. I hooked a scope probe to the test point and discovered that the logic level +5vdc is supposed to remain high for 200mS and the signal is only high for 120/125mS. Which is somewhat expected as the meter cycles between overload display and random numbers. I need to find data sheets on some of the obscure discrete components such as U4 and U5 both precision op-amps in an 8-pin can package. I will keep poking about as time allows. I have begun to put a test bench together again and pulled this old guy out and would really love to put it back in working order. Again thanks for any help.
Microsoft Surface Table looking for hard drive image - Page 1
Forum section: electronics / repair

author: Johnny10
author_rank: Frequent Contributor
timestamp: February 08, 2018, 03:37:07 pm
content: I am looking for HD image for 1st Generation Microsoft Surface Table.ThanksMy unit came without HD

author: ChuckDarwin
author_rank: Regular Contributor
timestamp: February 08, 2018, 10:21:17 pm
content: Try:https://support.microsoft.com/en-us/surfacerecoveryimageYou will need the device ID/serial number.(Edited to US URL)

author: Johnny10
author_rank: Frequent Contributor
timestamp: February 09, 2018, 04:23:20 am
content: Thank you Chuck, but this is for the 1st Generation Surface Table,No listing for Table on that page.

author: ChuckDarwin
author_rank: Regular Contributor
timestamp: February 10, 2018, 04:09:53 am
content: My error, I had read "tablet" not "table". Nice piece of unique kit you have acquired.Designed for Vista, but will also run 8.1. It looks like you could install vanilla vista and load in the driver kit for the positioning cameras and the app suite on top--assuming success in locating them.The PixelSense (ms name change) sitehttps://www.microsoft.com/en-us/pixelsense/default.aspxhas a broken links and drained of any really usefull info, but you could search elsewhere on the kit (file) names.Have a look here, too, if you haven't see it yet,https://joepweijers.nl/technical-notes/microsoft-surface/for info and links.
Info on fuse for TTi PFM1300 - Page 1
Forum section: electronics / repair

author: giosif
author_rank: Frequent Contributor
timestamp: February 09, 2018, 02:11:01 pm
content: Hello,Does anyone have any information on the fuse found on the board of the TTi PFM1300 frequency counter, please?It is located near the place where the battery cables connect to the board and it is inline with the supply from the battery.If quicker, a picture of that area of the board should be ok as well.Thanks!
Radeon 7950 voltage issues - Page 1
Forum section: electronics / repair

author: nano21
author_rank: Newbie
timestamp: February 13, 2018, 04:53:39 pm
content: Hi all,I have a problem with the 7950, voltage on the right side of the card on the mosfet is 0.1v (smaller vrm on the left of the gpu is ok). I did found Core channel on youtube helpful but hi did have 0.9v so its not the same problem. I dont see any physically damaged components on the board. Capacitors closer to the 6pin connectors (before mosfet) are measuring 12v. I have very very limited electronics skill but if somebody can point me in the right direction I can replace components on the board as I have access to the hot air station. I think its maybe the ic labeled CHiL because all gpu phases measure 0.1v or maybe its some kind of short somewhere?PSU is 750w from a workstation with two 6pin (as needed for the card) and thats not an issue. I also tried both bios, also booted win on the integrated graphics - 7950 is not recognized in the device manager.

author: KhronX
author_rank: Frequent Contributor
timestamp: February 14, 2018, 12:48:13 am
content: Can you measure the ohms between the VRM output and ground? With the power off, of course.

author: nano21
author_rank: Newbie
timestamp: February 14, 2018, 12:26:14 pm
content: Gpu vrm measures 0.6-0.7omhs, all six the same, but vram phase (left, closer to pink caps) measure 9.8ohms and one on the right I can`t even measure in the same range... When I changed multimeter to 20k range then measured 3.55.

author: KhronX
author_rank: Frequent Contributor
timestamp: February 14, 2018, 03:42:50 pm
content: "Of course" all six measure the same - their outputs are all in parallel.That being said, 0.6-0.7 ohms is a liiiitle bit (too) low, so there's a certain chance the GPU itself is bye-bye

author: nano21
author_rank: Newbie
timestamp: February 14, 2018, 04:06:17 pm
content: Similar readings as minehttps://youtu.be/fuuRg9M-QTA?t=42s
HP 6060A Firmware Wanted - Page 1
Forum section: electronics / repair

author: deepskyridge
author_rank: Regular Contributor
timestamp: February 07, 2018, 08:47:23 pm
content: I am looking for firmware from a HP 6060A electronic load.ThanksGary

author: samofab
author_rank: Regular Contributor
timestamp: February 08, 2018, 10:35:37 pm
content: These seem to be in vogue:https://www.eevblog.com/forum/repair/hp-6060a-repair-(manual-firmware-needed)/msg1411819/#msg1411819
Another faulty Keithley 2100. - Page 1
Forum section: electronics / repair

author: Oldtestgear
author_rank: Regular Contributor
timestamp: February 07, 2018, 02:35:05 pm
content: I recently acquired a Keithley 2100 that was donated to me as "very faulty". The wretched thing would power up but not do anything even though the display did change in sympathy with the button being pushed. Once in a while it would actually work for a few seconds, and then stop.After tearing it apart & a bit of probing around I found a fault. A previous owner had changed all the supply capacitors & broken a track that powered all the relays. A bit of rewiring & this was solved. It now works on DCV/ACV/DCI/ACI but not on continuity or resistance. The current is approx. 8-9mA on all resistance ranges & any resistor on the 100R range is measured at about 10x the real value. At least that seems to have signs of life.The fault seems to be in the current source but that is a far as I have got. Others appear to have similar issues & I am hoping that someone may have sketched out the circuit or provide a bit of guidance as I am now stuck.Thanks for any suggestions.Phil

author: TiN
author_rank: Super Contributor
timestamp: February 07, 2018, 03:08:34 pm
content: 2100 is not a real Keithley, so this thread might be much more useful if you squeeze some photos of innards for our common knowledge sharing.
Display top line cut off on HP 8591EM spectrum analyzer - Page 1
Forum section: electronics / repair

author: yanko
author_rank: Newbie
timestamp: February 02, 2018, 04:34:23 pm
content: I have a HP 8591EM EMC analyzer. The top half of the top line of the display is cut off making it impossible to read out results. (Photo attached) Basically, several pixel rows are missing.Before I get too deep into trying to fix this, I'm wondering if this is something that has to do with CRT vertical size/position that can be fixed by tweaking a pot, or is it a problem with whichever module is generating the video signal? If the latter, is it likely to be an easy fix?There are menu options that move the display in the vertical direction, but don't change how many pixel rows are displayed.Thanks!Yanko

author: cvanc
author_rank: Frequent Contributor
timestamp: February 02, 2018, 05:11:47 pm
content: I'm not familiar with the 8591 but if the display is a CRT as you say, the image size is entirely controlled by the scan/deflection system of the CRT.There may or may not be simple internal adjustments for image height and width - hopefully someone who knows this unit well will comment.Good luck getting it sorted out.

author: Tomorokoshi
author_rank: Super Contributor
timestamp: February 02, 2018, 06:15:59 pm
content: Not sure if there is a subtle difference but in the 8590C service manual:https://www.keysight.com/upload/cmc_upload/All/08590-90316.pdfStarting on page 33 there are detailed procedures for adjusting the display.

author: yanko
author_rank: Newbie
timestamp: February 02, 2018, 06:52:16 pm
content: Thanks for the replies. I actually already tried the adjustment procedure in the service manual. It only moves the image up and down within the screen but does not change the contents of the image.Also, based on my limited understanding of CRT monitors, changing the vertical size or position can only help if the issue is caused by the image falling out of the physical constraints of the CRT, which is not the case here. Not knowing the details, it feels that this can be caused by the vertical SYNC pulse not lining up with the video signal, but I was wondering if anyone has seen this same issue before. Maybe the sync signal timing is adjustable somehow?Yanko

author: MarkL
author_rank: Unknown
timestamp: February 06, 2018, 05:03:44 pm
content: There also the time/date one line above the "hp" logo which is totally off the screen.Check that both your SYNC settings are set to NRM. It can cause this exact problem. It is on page 3 in the CONFIG menu.

author: yanko
author_rank: Newbie
timestamp: February 06, 2018, 06:40:41 pm
content: This was it! Thank you, MarkL.I'm very glad I hadn't yet opened it and tried to mess with the video module!
Need help - identify IC - Page 1
Forum section: electronics / repair

author: flolic
author_rank: Frequent Contributor
timestamp: February 08, 2018, 04:10:54 pm
content: Hi, I am looking for a info on this TSSOP8 chip from ST, with marking 556R8. It is most likely SPI flash, but I can't find exact type.Chip is on the main board of Canon 70D camera.

author: flolic
author_rank: Frequent Contributor
timestamp: February 08, 2018, 04:37:08 pm
content: Never mind, I figured it out. It's most likely M95256 SPI eeprom.