hybridfree/eevblog-posts huggingface dataset:
Faulty power-pcb on Siemens Logo PLC - Page 1
Forum section: electronics / repair

author: asdqwerty
author_rank: Contributor
timestamp: June 06, 2016, 04:37:14 pm
content: On a place with lot of inductive load, SON-lamps, there are used some Siemens LOGO PLC's.They tend to fail. It seems like the powersupply is the problem. I suspect voltage spikes.They consists of 2 pcb. One power and relay (in-out) pcb, and one display-cpu pcb.What I often do, is buy a new one, taking the power pcb from the new and mix with the old display-cpu pcb. And then it all works again.I guess it's one component that fails..Maybe someone have a suggestion for which component to investigate..?Attached is pictures with two models of the power-input-output-pcb

author: SeanB
author_rank: Super Contributor
timestamp: June 06, 2016, 05:40:51 pm
content: Standard SMPS unit so the TOP232 likely has died, along with the 2 SMD capacitors on the board, and check the input side resistors and diodes for being open circuit.To prevent it happening again get some inline mains filters on the power to the PLC units, it will help prolong the life of them a lot.

author: asdqwerty
author_rank: Contributor
timestamp: June 06, 2016, 07:29:52 pm
content: ok. I'll take a closer look at that area !
Tek 2215 problem - Page 1
Forum section: electronics / repair

author: jmgallag
author_rank: Newbie
timestamp: June 03, 2016, 03:01:14 pm
content: Hi,Another beginner with scope repair questions... I picked up a 2215 in a stack of equipment pretty cheap. It was very dirty, and after some cleaning of the rotary switches with contact cleaner, I can get a trace. The problem at this point is the trace is only decent in the middle of the vertical adjustment, and the vertical seems limited. The first two pics are the top and bottom limits for ch 1. The third pic is the calibration square wave. The fourth pic is what the trace morphs into when moved up using the vertical position. At the extremes of the vertical adjustment, the trace becomes a flat line.I have the service manual PDF. The power supply voltages are all within the stated ranges, except the high voltage. I don't have a HV probe, so I can't check that.Questions:Could the HV supply be the problem? If so, I will get a HV probe to check it.Is this a likely bad CRT?Is the vertical circuit the likely problem? If so, I will continue to troubleshoot down that path.Thanks,Jim

author: David Hess
author_rank: Super Contributor
timestamp: June 04, 2016, 12:02:27 am
content: QuoteProbably not, when the x10 sweep magnification is *not* on, how many divisions wide is the sweep? It should be about 10 to 11 divisions if the high voltage supply is working correctly.QuoteNo, if the CRT was damaged, then the traces would be distorted on the screen relative to the CRT geometry and I see no evidence of that.QuoteThe vertical output amplifier depends on the +30 volt supply. Make sure it is +30 volts and that the ripple is very low; an AC measurement using your voltmeter should read basically zero.Check the condition of the collector load resistors at the output of the vertical CRT amplifier. These are R378, R379, R388, and R389 under the neck of the CRT. They run hot and may fail. Inspect them to see if they are cracked or if their epoxy coating flakes off.Does channel 2 operate in the same way as channel 1?

author: jmgallag
author_rank: Newbie
timestamp: June 05, 2016, 02:41:42 am
content: Thanks!I will make those checks and post my results.Jim
HP 438A RF power meter fan info needed - Page 1
Forum section: electronics / repair

author: MarkL
author_rank: Unknown
timestamp: March 28, 2015, 07:13:19 pm
content: I need to get a new fan for an HP 438A power meter and unfortunately the old fan has no model information on it. It looks like the sticker fell off. It's made by Papst and is a standard 60mm x 60mm x 25.4mm, 12VDC. There's a million different fans out there that would fit but I'd like to get one with the right CFM.Earlier 438A units had a strange fan that had 4 wires with a separate driver module and was probably some kind of brushless DC motor. And that's the one shown on all the service manuals I could find. The one I have is NOT that.If someone has one of these meters, could you pop the cover and read the fan model number? Or even look it up in a more recent service manual?Thanks!

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: March 30, 2015, 02:05:00 am
content: My 438B came in a with a broken mount on the fan and I replaced it with this parthttp://www.digikey.com/product-detail/en/0/381-2487-NDIt is a little expensive but I am pretty sure I matched it as close to the original as possible.BTW, my power meter had some capacitors rattling around inside when I got it. I couldn't see a place that was missing them until I realized there was a board sandwiched between the top and bottom pcb's. When I removed them, I found that three of the four wet tantalum capacitors leaked and ate through part of the board and the leads. All four were replaced and the board was cleaned. There is also a lithium battery hidden in there too.

author: MarkL
author_rank: Unknown
timestamp: March 30, 2015, 04:21:10 pm
content: Thanks for the part pointer!Working backwards from the part number, this fan is used in a lot of HP gear. I think you got it right.Interestingly, the part finder at Keysight lists it as obsolete in the equipment that uses it. After another level of obsolete part number, they have a current part number of 5065-7092 with a picture of an NMB-MAT 2410ML-04W-B60-B00, which is also available from DigiKey as P15633-ND. Half the price but made in China. I think I'll stick with the Papst fan.No sign of any capacitor issues on my boards, but thanks for mentioning it. The battery is only used to store the front settings, setups, and the last sensor zero/cal for A and B channels.

author: SV1EOR
author_rank: Contributor
timestamp: June 01, 2016, 07:50:49 pm
content: Can You tell me if your models are droing air from out in the power supplay?I think that it is not right to send the hot air from the power supplay in the pcb partitions...!

author: MarkL
author_rank: Unknown
timestamp: June 02, 2016, 01:50:31 am
content: Quote from: SV1EOR on June 01, 2016, 07:50:49 pmI have two 438A meters now, and they both suck air in the back and blow it out the sides.I agree it doesn't seem optimal, but I was consistent about the direction of the fan I replaced, and neither of them appear to have had any work done on them before I bought them. Based on this, I have to assume that's the intended design.
[SOLVED] Pyramid PS-21KX Repair - Voltage Stability Problem - New Regulator - Page 1
Forum section: electronics / repair

author: Steve Wayne
author_rank: Contributor
timestamp: May 22, 2016, 11:23:07 pm
content: I have a Pyramid PS-21KX DC regulated power supply that drops in voltage output as the load increases. This 20A supply drops from 13.8V to 12.7V under a 7A load and continues dropping (I’m sure) under increased load. The initial problem with this supply was a direct short under loads greater than 150mA, while otherwise appearing to power-up normally (except the no load voltage was low, at 12.4V.) I replaced all 4 of the pass transistors as they were all found to be shorted at base to collector. The mains rectifier tested ok. I replaced the LM723CM regulator IC as well. The associated TPI41C transistor (typically) tested ok. The 5 filter capacitors “look” ok, and the control circuit board components have no obvious signs.I’d certainly appreciate opinions from anyone who has knowledge of similar symptoms and diagnosis reported in this or similar Pyramid supplies. Thanks!

author: Vgkid
author_rank: Super Contributor
timestamp: May 23, 2016, 01:41:16 am
content: Not sure about this model. Have you checked any power resistors in the unit(ones needed for parallel transistors), that are in series with the load.

author: TheMG
author_rank: Frequent Contributor
timestamp: May 23, 2016, 04:27:13 am
content: As Vgkid suggested, I would check resistors and make sure they are within tolerance. Chances are one or more of them could be open or have gone out of tolerance due to the excessive current through the resistors when the transistors failed short.

author: Steve Wayne
author_rank: Contributor
timestamp: May 23, 2016, 06:19:22 pm
content: Thanks Vgkid,, yes I had checked those 4 base resistors and came up with the requisite 2.2M Ohms.

author: Steve Wayne
author_rank: Contributor
timestamp: June 01, 2016, 09:27:36 pm
content: Thanks for your assistance. I obtained another PS-21KX and found that it behaved the same as the one I repaired. The voltage drops as described above when loaded. I certainly didn’t expect this to be the case. So much for “linear” as a power supply. S~
One channel brighter/ louder than the other Yamaha RX-V530 - Page 1
Forum section: electronics / repair

author: kasumyku
author_rank: Regular Contributor
timestamp: May 31, 2016, 12:44:15 am
content: Hi everyone,I'm trying to figure out what can cause one of the channels to have brighter sound than the other.So far I have opened it and saw some very light oxidized connections so I sprayed them and the volume/bass/ treble knobs also speaker output connections/RCA inputs with electronic cleaner (I also used a small plastic brush to remove the oxidation)I've checked the bias and both channels show same reading.Any suggestions would be much appreciated.p.s.: Already changed speakers + wires with new ones to eliminate amplifier,but same result.Tried same speakers with a different amplifier and they sound OK.Thank you in advance!
Lambda LM-D power supply output very high - Page 1
Forum section: electronics / repair

author: Puffie40
author_rank: Regular Contributor
timestamp: June 04, 2016, 12:59:21 am
content: I had a Lambda LM-D 28V linear power supply that I've been trying to fix. The output is belting out 40V with nothing connected and has been a headscratcher for me.the components that the manual suggest would fail have tested okay. all the transistors have passed the diode test on my multimeter and all the resistors have tested good.Im at a loss now of what to do. any suggestions?

author: Vgkid
author_rank: Super Contributor
timestamp: June 04, 2016, 05:59:30 am
content: If you have 40v on the output. That means that either the feedback circuitry has lost regulation, or that the output transistors have gone short. First off check to make sure that the output is wired up correctly. If not the regulation circuitry won't be able to actually see the output. If thst is good, check any wiring,traces to see if they are missing/broken. Lastly go deeper...

author: sync
author_rank: Frequent Contributor
timestamp: June 04, 2016, 03:36:13 pm
content: I'm assuming that the power supply has remote sensing. Are the sense terminals connected? With open sense lines it's common to have a (much) higher output voltage.
Power Designs 2005 Power Supply - Page 1
Forum section: electronics / repair

author: wn1fju
author_rank: Frequent Contributor
timestamp: May 25, 2016, 12:02:36 pm
content: I've recently noticed that my Power Designs 2005 supply takes about one or two minutes to stabilize when I change the voltage (no load). It acts almost like there is a capacitor charging/discharging. For instance if I go from 1V to 10V, it will immediately jump to 9.998V and then slowly ramp up to 10V (all values approximate!). If I change back to 1V, it will jump to 1.002V and then slowly go down to 1V. Once I wait for it to stabilize, it is rock solid (I measured 14 uV drift over one hour). My other precision power supply, the HP 6113A, hits the voltages instantaneously, so I suspect the 2005 may be faulty. All the electrolytics were replaced a couple of years ago when I got the 2005.If you have a 2005 (or similar Power Designs precision supply), does your unit act like mine?Otherwise, any ideas?

author: vindoline
author_rank: Unknown
timestamp: May 28, 2016, 01:05:33 pm
content: I have a 2005A and it does not do this. I don't have any suggestions for you, sorry.

author: saturation
author_rank: Super Contributor
timestamp: May 29, 2016, 03:25:57 pm
content: The parallel output cap can be failing; check the ripple is to spec; short the outputs to discharge the output cap and get output voltage down quicker; you can do this on the fly by checking the current limit, the switch does the shorting for you. On my 4 units, the units drop to within 1mV nearly instantly, but takes a while to settle at 10+uV level.

author: wn1fju
author_rank: Frequent Contributor
timestamp: May 30, 2016, 12:36:33 am
content: It has the look and feel of a capacitor charging/discharging somewhere, but I can't put my finger on it.Shorting the output via the front-panel current set button, it always drops down to a few mV instantaneously (I would hope so given it is a physical short!).But when I release the button, it ramps up to the set voltage. The ramp-time is 1) nearly instantaneous for 1V, 2) about 2 seconds for 9V, and 3) about 6 seconds for 19V. And I'm considering it done when the 1 mV digit on my DMM stops moving (the DMM is set to 1 PLC, so it is updating very fast and is not the cause of the delay). The ramp-up is certainly non-linear, as it gets to about 18.900V within a second before taking another 5 seconds to stabilize at 19.000V.Same basic behavior when down-ranging to a lower voltage - the greater the change, the longer the time.As I said before, once it stabilizes, it stays put well within the drift spec. And the noise spec seems fine (at least as far down as I can measure). The 100 uF output cap is new.

author: saturation
author_rank: Super Contributor
timestamp: May 30, 2016, 01:17:27 pm
content: It sounds like its working well then. On the PD 2005 there are 2 small value filter caps between V+ and V- outputs and earth ground [see schematic], they could also be failing and cause those small variances.
replace Xilinx Spartan-6 for repair Rigol DS2000A series - Page 1
Forum section: electronics / repair

author: Mar.S.
author_rank: Newbie
timestamp: June 01, 2016, 10:24:18 pm
content: Hi. Maybe someone knows whether you can safely replace the Xilinx Spartan-6 for the same? Is there a downloadable command sequences bind to the ID of Spartan-6 core? Sorry for my bad English and thanks for all answers.
Repair of Hytera DMR radio [FIXED] - Page 1
Forum section: electronics / repair

author: on4top
author_rank: Regular Contributor
timestamp: May 24, 2016, 02:39:20 pm
content: I have PD765 Hytera radio with a small problem .Seems to be a well known problem Q605 a P-MOS Ttransistor that dies when connecting the speakermike wrong.Problem is .. schematic shows a PNP transistor .. with a P-Mos type SI1013R (SI2307BDS) ...Second problem seems the schematic of the 400-470Mhz version is little bit different compared to 450-520Mhz version .In the 450-520Mhz it is a P-Mos Transitor in the schematic ..So now i'm confused .. will replacing Q605 solve my issue ? And what to replace with ? P-MOS or PNP ??The print on the curent transistor is DJA ( the J placed horizontal ) .. i have no idea what transistor this is ...

author: stj
author_rank: Super Contributor
timestamp: May 26, 2016, 12:59:28 am
content: is it a reflection, or does it have 4 pins!

author: Theboel
author_rank: Frequent Contributor
timestamp: May 26, 2016, 01:16:01 am
content: I think its PNP one,reason : its use 2 resistor in parallel like in PNP schema but for sure I will measure if its 3K3 (resistor in red circle) well You can be sure its PNP one

author: on4top
author_rank: Regular Contributor
timestamp: May 26, 2016, 02:35:29 am
content: Quote from: stj on May 26, 2016, 12:59:28 amno it has 3 pins .. seems a SOT323 package .And yes i also suspect it to be a simple PNP .Hytera says 3410001000020 and google says me this should be 3410001000020 Transistor 2SA1745 .I ordered some BC857BW ..look a good drop in replacement for 2SA1745 .http://be.farnell.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=15001&langId=32&urlRequestType=Base&partNumber=1773625&storeId=10154Wil see what that does ..it's verry confusing .. those Chinese company and schematics lol ..

author: on4top
author_rank: Regular Contributor
timestamp: May 28, 2016, 11:10:10 pm
content: Yesterday i received the BC857 PNP SOT323 from Farnell/Element14 .Seems the package is a bit larger .. but the pins aligned fine .. so i could solder it nicely on the pads . ( maybe it's SOT416 ? i now see BC857 also is available in SOT416 )Put the thing back to gether .. and YES .. repair succes .. external speaker works again !Have no idea what package the original part is .. still don't now for sure what type it is ..Only thing i'm sure .. it's a PNP ...
Fluke 1900A frequency counter  - Page 1
Forum section: electronics / repair

author: Ranger14
author_rank: Regular Contributor
timestamp: May 25, 2016, 08:52:01 pm
content: I got a great deal on a Fluke 1900A frequency counter off ebay.. Today I got it in the mail and it seems pretty nice but no power .. So I tore it down and the fuse was blown and after replacing the unit now works .. Is there anything I should check or would cause the fuse to blow???

author: tautech
author_rank: Super Contributor
timestamp: May 25, 2016, 08:58:19 pm
content: The user manual?Maybe the previous owner didn't.http://exodus.poly.edu/~kurt/manuals/manuals/Fluke/FLUKE%201900A%20Instruction.pdf

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: May 26, 2016, 03:49:57 am
content: Just be sure you used the proper size fuse and not a larger one. If it blows again investigate further.I would take a look side just to see if there are any signs of trouble/cap leakage, etc.

author: Ranger14
author_rank: Regular Contributor
timestamp: May 27, 2016, 03:42:40 pm
content: Quote from: tautech on May 25, 2016, 08:58:19 pmThe unit came from a company of some sort and it was calibrated in 2011 and ends in Aug 2016.. You have to break the calibration sticker in order to change the fuse hence why the unit was sold and mostly cause of the age too ..

author: Kleinstein
author_rank: Super Contributor
timestamp: May 27, 2016, 04:47:44 pm
content: This is a really old counter. The input stage is still reasonable quality, but resolution and the reference stability are not really good by today's standard. Well possible to trough such an old counter out because a better one is needed.

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: May 27, 2016, 06:04:01 pm
content: I think it shouldtake an external 10MHz reference, which makes more sense that buying multiple prices of equipment with OCXOs. Check the back.Also, rarely do you need a more accurate counter unless you are doing RF stuff. Tools only need to be as good as they need to be. Something better will always be cheaper tomorrow.

author: Ranger14
author_rank: Regular Contributor
timestamp: May 28, 2016, 12:27:22 pm
content: Quote from: FlyingHacker on May 27, 2016, 06:04:01 pmThe unit is really old and has input only ...From what I can tell the unit is still within spec and work perfectly for me.. As right now I have a 60mhz scope and don't plain on using RF anytime soon..

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: May 28, 2016, 04:33:16 pm
content: Ah, I see that in the manual now. No 10MHz reference input. Could be a fun project to add a better reference. They can often be had really cheap on eBay.Still a useful instrument. I have been known to use two or three frequency counters at once to measure things like divide by N circuits, etc. I have some old Data Precision counters (almost as old as your Fluke, but I think they do ~100MHz) that I use as extra counters when I just need to check a few frequencies at once. Comes in handy.
Looking for nad 7240pe service manual - Page 1
Forum section: electronics / repair

author: ilanko
author_rank: Contributor
timestamp: May 27, 2016, 12:58:54 am
content: Hi guys,Please your help, looking for service manual good quality PDF of NAD 7240pe Stereo ReceiverThank you

author: mzacharias
author_rank: Frequent Contributor
timestamp: May 27, 2016, 07:19:11 pm
content: http://www.hifiengine.com/manual_library/nad/7240pe.shtmlhttp://elektrotanya.com/nad_7240_sm.pdf/download.htmlBoth sites require registering (free)

author: JacobPilsen
author_rank: Regular Contributor
timestamp: May 27, 2016, 07:55:24 pm
content: You don't need registration on ElektroTanya, if you are satisfied with 2 downloads per day.

author: ilanko
author_rank: Contributor
timestamp: May 28, 2016, 03:07:56 am
content: Than you guys.
Weller 1002 solder iron replacement needed - Page 1
Forum section: electronics / repair

author: Sparky_Freak
author_rank: Contributor
timestamp: May 29, 2016, 08:43:36 am
content: i bought a Weller 1002 station but i don t have the iron i was wondering if anyone knew where to get a replacement iron or a substitute one any help is appericated

author: DTJ
author_rank: Super Contributor
timestamp: May 29, 2016, 11:38:11 am
content: Is that the magnastat style iron?If so I'd also like to know, there don't seem to be any on eBay. I would have thought with the number of old Weller irons out there that someone would be making knock-offs.

author: nanofrog
author_rank: Super Contributor
timestamp: May 29, 2016, 04:40:11 pm
content: Quote from: Sparky_Freak on May 29, 2016, 08:43:36 amThe EC1201A (40W) is the iron that usually came with it, although they offered both the EC1302 (20W) & EC1503 (40W) irons as well (both of these are more of a pencil shape). Unfortunately, these stations are EOL, so parts are getting hard to find (used or NOS on eBay). Tips are still available as they're used in other irons (ET series for the EC1202 iron; not sure on the others, so that will take some research).As per modifying the base unit to use another iron, that should be possible. You just need to know what the resistance of the heating element and temp sensor for both the existing unit (from a good iron), as well as the intended iron in order to find a viable match. Unfortunately, I don't know the acceptable values, but they can be found or calculated (i.e. manual/tech sheet for the EC1202 or EC1503), or even contacting Weller to request it.Fortunately, I found theEC1302B Tech Sheet, which contains the resistance values for both the heating element and sensor. The heating element data won't be the same (half the power consumption, so applying Ohm's Law should get you the range for the EC1202A iron). I'd expect the temperature sensor values to be consistent across all the irons that work with that base unit, and pin-outs will be the same as well.Hope this helps, and good luck.Quote from: DTJ on May 29, 2016, 11:38:11 amThe EC1002 is a temperature controlled station.

author: Sparky_Freak
author_rank: Contributor
timestamp: May 31, 2016, 12:52:48 am
content: Quote from: nanofrog on May 29, 2016, 04:40:11 pmthank u so much will try to modify the unit ill post more info as i attempt it
HP/Agilent 34401A eeprom checksums - Page 1
Forum section: electronics / repair

author: meandeev
author_rank: Regular Contributor
timestamp: May 27, 2016, 07:44:19 pm
content: In the 34401a-eeprom are the calibration data (and the calibration string) stored.I´m now able to "decompile" the calibration string, but not the checksum.Does anybody have one of the checksum calculation of- Cal checksum- secure state Cal checksum- string data Cal checksum- DCV corrections Cal checksum- DCI corrections Cal checksum- RES corrections Cal checksum- FRES corrections Cal checksum- AC corrections Cal checksum- GPIB address Cal checksum ?
Tek TDS3000B front panel encoders - are these custom made? - Page 1
Forum section: electronics / repair

author: Jwalling
author_rank: Unknown
timestamp: May 27, 2016, 10:26:50 am
content: To finish up a repair on a TDS3012B I need to replace one of the rotary encoders that has a broken shaft. But nobody seems to carry the part. These encoders mount to the PCB which was designed especially for this part. They are mounted to the PCB, then the legs are melted over on the other side of the PCB. They are manufactured by Bourns and are not on their website. Does anyone know where or if these are sold anywhere? See attached pictures.Thanks!

author: AndyC_772
author_rank: Super Contributor
timestamp: May 27, 2016, 11:43:44 am
content: I'm pretty sure they're bespoke.A few years ago I replaced the front panel on a TDS3034B on which one of the encoders had simply worn out. The entire PCB assembly was available as a spare part, and not all that expensive either IIRC.

author: Jwalling
author_rank: Unknown
timestamp: May 27, 2016, 03:37:56 pm
content: Quote from: AndyC_772 on May 27, 2016, 11:43:44 amI kind of thought so, but thanks for the confirmation. At this point I'm on a tight budget as I just got laid off last week after 31 years as a Sr. repair technician. For now I moved the broken encoder to the waveform intensity control; who needs that anywayBesides, I cut a little slice in the shaft so I can use a small flat bladed screwdriver if needed.Thanks for that!Jay

author: AndyC_772
author_rank: Super Contributor
timestamp: May 27, 2016, 03:58:35 pm
content: I confess, I didn't look all that hard to see if the encoder itself was available, because in my case the PCB pad underneath was the part which had worn through. The encoder itself was OK, just not the board it was attached to.
DER EE DE-5000: Replacement for diode D5 - Page 1
Forum section: electronics / repair

author: nidlaX
author_rank: Frequent Contributor
timestamp: May 25, 2016, 08:35:56 am
content: I'm in the process of repairing a DE-5000 that had a burnt reverse polarity protection diode at D5 (it likely failed short before, but was made worse by me after I sent 3W through it...). It's a small glass surface mount diode (seehttps://youtu.be/Wcm5-CgX3Wc?t=3m12s).Any suggestions for a suitable replacement? Also, maybe it's just me, but it seems like a mediocre idea to do reverse polarity protection with only a diode and no fuse / poly fuse...

author: nidlaX
author_rank: Frequent Contributor
timestamp: May 25, 2016, 08:08:55 pm
content: After doing some research, I've decided to go with a miniMELF Schottky diode with a specified 600 mV V_f at 200 mA.
Need B&K Precision 1500 Oscilloscope Service Manual - Page 1
Forum section: electronics / repair

author: houdatto
author_rank: Newbie
timestamp: May 25, 2016, 08:02:14 am
content: Does anyone have a source for a service manual for a B&K Precision 1500 Oscilloscope? I can't find anything on line other than a site that has one for sale for $31. B&K did send me several pages of PDFs with schematics and parts lists but there must have been more than one variant of this scope as the schematic for the vertical amplifier board which they sent me, the part I am working on first, does not match up with the board in my scope. Any help would be appreciated.

author: tautech
author_rank: Super Contributor
timestamp: May 25, 2016, 08:16:40 am
content: Quote from: houdatto on May 25, 2016, 08:02:14 amAs you have already made contact with B&K, thank them for the SM and provide the with further info so they can send you any revisions.SN# and PCB #'s is what they'll need.Failing that there's a number of manual repository links in the sticky at the top of this board.Check their B&K folders as they don't always show as hits in a Google search.Let us know how you get on.
Optio E30 stopped counting and saving images properly. - Page 1
Forum section: electronics / repair

author: ResR
author_rank: Regular Contributor
timestamp: May 25, 2016, 03:33:46 pm
content: I have Pentax Optio E30 for 8 years, after counting to 9999 it started to act weird. When before it saved images in it's numeric order into one "100pentx" folder, now it creates new folder every time I turn it on and starts counting from 0001 again, creating a whole clusterf... of images with same name. Has anyone else stumbled onto such a failure and is it repairable?Edit: It broke other cheap SD card

author: AndreasF
author_rank: Frequent Contributor
timestamp: May 26, 2016, 06:09:23 am
content: According to the user manual (e.g. here:http://www.camera-usermanual.com/manuals/pentax/Pentax_Optio_E30.pdf) page 133, this mode of saving images is just one of the options available. This can be changed in the settings. This doesn't explain why it creates multiple folders for the same day. I would try changing the mode back to the "standard", but perhaps you also have to fully reset the camera and format the SD card and the internal memory.

author: ResR
author_rank: Regular Contributor
timestamp: May 26, 2016, 10:05:37 am
content: It did the same with "standard" mode, I took the image after third SD card format, testing if the changing that mode would make any changes. I also tried to reset it by disconnecting it until it forgot the date and time, then reset and format it from the settings menu but the bug is still there.

author: AndreasF
author_rank: Frequent Contributor
timestamp: May 26, 2016, 11:38:46 am
content: Have you tried formatting the internal memory (i.e. "format" with no SD card in it)? Since this appears to be a bug related to the counter reaching 9999, that may reset this counter. If that also doesn't work, I think it's time to look for a new camera.

author: ResR
author_rank: Regular Contributor
timestamp: May 26, 2016, 12:14:59 pm
content: Formatted without SD card and it was still the same. I was afraid of that I have to look for new camera.
lorex security camera night vision model LW2711AC1 - Page 1
Forum section: electronics / repair

author: mrfixstuff
author_rank: Newbie
timestamp: May 20, 2016, 07:23:33 pm
content: Hi new herei working on a wireless lorex security camera model LW2711AC1here's what i think happened..... at night the camera was pointing at a outside fire ( very bright ) it would set off the motion sensor and the camera would record ( this may have went on most nights for a year ) ... by the time they found out what was going on the night vision is about shot...the IR LED's are working i can see the light with one of my camera's at night ..so my question is...... is the image chip toast ?thanks

author: tautech
author_rank: Super Contributor
timestamp: May 20, 2016, 09:48:48 pm
content: Welcome to the forum.That's a possibility one would imagine.... I couldn't say for sure but your thread's worth a bump.

author: mrfixstuff
author_rank: Newbie
timestamp: May 21, 2016, 02:44:24 pm
content: thanks for the bumpi will double check the IR LED's as it seems to pick up light good at night ..........like the headlights of a car

author: bitseeker
author_rank: Super Contributor
timestamp: May 22, 2016, 04:19:22 am
content: I can't imagine that a little fire would be brighter than broad daylight. Unless that camera has a completely different sensor for low light, perhaps something went awry with the gain control (either software or hardware).

author: Muttley Snickers
author_rank: Unknown
timestamp: May 22, 2016, 04:43:45 am
content: The IR LED's on most cameras generally operate independently of the camera itself and are usually controlled by the LDR as seen in the picture below, if the camera face and in turn the LDR never gets dark enough then the LED's will never be at full illumination, the fire may not be bright enough for the camera to see normally but too bright for the LED's to switch on.Also on some of these types of cameras there may be a setting for the IRE threshold or sensitivity level and this will dictate the switch from colour to black and white so check this as well, some of the LED control options might also be adjustable in the menu settings but every camera is different.

author: mrfixstuff
author_rank: Newbie
timestamp: May 23, 2016, 07:01:13 pm
content: thanks for the infoi went to the house and looked at the spot where the camera was and the sun shines right in the front of the camera for a few mins in the after noonalso i will take the camera and put it beside one of my camera's that has a good night vision and see if maybe it's the IR LED's... see how the bad camera works with a good IR lightwill post back when i do the testthanks

author: bitseeker
author_rank: Super Contributor
timestamp: May 23, 2016, 07:09:21 pm
content: Those are good follow up tests. Direct sunlight into the camera lens isn't good news, though. It could fry the sensor.
Agilent/Keysight DSOX2022A won't boot! - Page 1
Forum section: electronics / repair

author: JoeB83
author_rank: Regular Contributor
timestamp: September 17, 2015, 01:27:19 am
content: Hi All,A friend of mine brought me his Agilent DSOX2022A that won't boot. I have the same scope, I guess that's why he brought it to me, but I have the most recent firmware, his is from 2012.Anyway, what happens is: it turns on, shows the boot screen, cycles the lights on the control panel, and repeats infinitely. I've tried leaving the scope on for an hour, nothing; I've looked at the service manual, and tried everything I could short of opening it up. Opening it isn't a problem, I just don't have a clue where to start or know what to look for.I contacted Keysight a few days ago, and all they'll say is that it needs to be returned to them. No troubleshooting advice.Unfortunately the warranty expired in June, so the owner doesn't want to return it to Keysight.Here's a video if that'll help:https://youtu.be/JJ1bZfaCyPE(Yes, that's my goofy dog in the background trying to help.)Thanks in advance for any help or ideas at all!

author: LA7SJA
author_rank: Regular Contributor
timestamp: September 17, 2015, 05:49:57 am
content: If you search for this rather long treadhttps://www.eevblog.com/forum/testgear/dsox2000-and-3000-series-licence-have-anyone-tried-to-hack-that-scope/you will find that it is possible to boot this scope from a USB drive (given firmvare <2.36) and then try a firmware upgrade. Try the 2000XSeries.02.35.2013061800.cab first. The 2.35 version firmware is the newest that supports USB boot.Johan-Fredrik

author: JoeB83
author_rank: Regular Contributor
timestamp: September 17, 2015, 07:06:41 am
content: Quote from: LA7SJA on September 17, 2015, 05:49:57 amThank you, sir!

author: tec5c
author_rank: Frequent Contributor
timestamp: September 17, 2015, 07:18:20 am
content: Did this just happen out of the blue? Or was he trying to do a firmware upgrade at the time?

author: JoeB83
author_rank: Regular Contributor
timestamp: September 17, 2015, 07:50:37 am
content: As far as I know, it happened out of the blue. He told me he bought the scope nearly three years ago and hasn't tried to update the firmware since. I'll double check @ work tomorrow.

author: Hydrawerk
author_rank: Super Contributor
timestamp: May 23, 2016, 06:38:32 pm
content: Any news, please?

author: LA7SJA
author_rank: Regular Contributor
timestamp: May 23, 2016, 06:57:18 pm
content: I think you would find this tread interesting:https://www.eevblog.com/forum/testgear/agilent-dsox2024-won't-boot/Johan-Fredrik
12V TV Fuse identification - Page 1
Forum section: electronics / repair

author: splin
author_rank: Frequent Contributor
timestamp: May 22, 2016, 06:17:03 pm
content: My neighbour connected 12V with the wrong polarity to his Kenmax 19LVD00D1 19" LCD TV and consequently I've been asked to take a look. A 3A 250V fuse has blown so hopefully it will be easy to fix.The fuse is a through hole glass type, 11mm x 4mm covered with black heat shrink marked "BESR TUBE". The fuse itself is marked '3A 250V' at one end and '3D' plus some certification symbols. One I can't identify is an '<' in a circle, but rotated anticlockwise such that the lower line in the < symbol is horizontal.The fuse wire is straight so I assume it is simply a medium speed type but the marking on the PCB is T3A/250V so does that mean a slow blow? Any recommendations as to what type I should replace it with?

author: tautech
author_rank: Super Contributor
timestamp: May 22, 2016, 09:30:03 pm
content: If you have a graveyard of old PC PSU's some of them might have TH mains fuses you can re-purpose.Surely you can but these things but I'm not sure where.Otherwise try to find some that have the fuse element soldered in and add the wire extension needed to make TH use possible.You might have to play around with different temp solders to prevent the wire extensions falling of when soldering to the PSU pads. Otherwise use some "clip on" heatsinking to keep the heat from getting to the fuse.

author: splin
author_rank: Frequent Contributor
timestamp: May 23, 2016, 02:20:48 am
content: Quote from: tautech on May 22, 2016, 09:30:03 pmThanks tautech. I had considered doing exactly that but through hole fuses do seem to be available on ebay.My main question though was what *type* of fuse should I use - a standard speed or slow, 'T' type? Since it won't be easy to replace I don't want to use a standard fuse if it needs a slow blow because of inrush currents. On the other hand I don't want to use a slow fuse if it isn't required, reducing its protection.

author: tautech
author_rank: Super Contributor
timestamp: May 23, 2016, 02:31:59 am
content: IMO slow, in order to withstand power on inrush currents of a SMPS.But as you don't know the design tolerances there's no way to know if the designer didn't allow for inrush.Often if slow is required it's marked on the overlay.

author: TheMG
author_rank: Frequent Contributor
timestamp: May 23, 2016, 04:23:48 am
content: Before you go out of your way to find an exact replacement fuse, I would just throw in whatever 3A fuse you can find just so you can at least test the TV and assess whether there is anything else wrong with it.If the manufacturer did not include a reverse polarity protection diode in the design, there is almost guaranteed to be some damage to the power supply circuitry. Even if it is equipped with a reverse diode, a lot of times that will fail short by the time the fuse opens.So there definitely are some other things to check.
Samsung S22a100n monitor repair. - Page 1
Forum section: electronics / repair

author: Refrigerator
author_rank: Super Contributor
timestamp: May 22, 2016, 09:21:35 pm
content: The other day i stumbled upon a rather recent monitor in the dumpster and thought to myself that it would be just a quick cap change on the PSU to get it working again, but i was wrong.Firstly, this monitor has an external PSU, which i do not have, althogh it did rig a couple wires up to the board for power, so there must be something else wrong.At first i tried to give it power, but with no success, i thought that the main board was dead, that was untill it gave away some light and a "no signal" image for about a second and then died again.I then pulled out my DIY RF detector to probe the crystal and the results were rather interesting.It seems like the crystal is off untill i press the on button and it starts pulsing on and off in about one second intervals, then if i press the on button again at the right time the crystal activity jumps up for a couple seconds and the monitor powers up for about one second and dies.Not sure what it could be, maybe the internal DC-DC is faulty, but then it wouldn't work at all if that was the case, the processor seems allright, i had it plugged into my PC and had a glimpse of my desktop for a second till the monitor died.I'll try to get a more graphical representation of the crystal activity tomorrow.Thanks.

author: tautech
author_rank: Super Contributor
timestamp: May 22, 2016, 09:39:29 pm
content: Despite it using an external PSU there will likely be an internal SMPS that could be shutting down from an over-current condition.Bad caps is the normal cause.

author: Shock
author_rank: Super Contributor
timestamp: May 23, 2016, 03:40:28 am
content: Had a quick looksee if thisis the correct buck converter. It looks something like that from the layout of components I can see to the right of the IC.You want to test the supply input and output (does the input or output ever go down?), test components around it, check ripple, isolate it and put a load on it if you have to, if it looks flaky double check what the IC is and replace it. Hot and cold testing is also a good idea.
Good will Fellows laminator, for PCB transfer. Appears broken, is it fixable? - Page 1
Forum section: electronics / repair

author: rwgast_lowlevellogicdesin
author_rank: Frequent Contributor
timestamp: May 22, 2016, 03:59:06 am
content: I got a fellows Saturn 95 laminator (seems to be in the 100 range new and working) for 6 bucks. Kind of cool has a 3 mill and 6 mill option on top. Seems to suck my radioshack clads right through, and there is even a lever to stop the thing and apply pressure.When I first got it I thought it worked, turns out the stand by light never goes off! I took half a** apart and found the thing was producing no heat. From what I understand the heating elements are in the rollers themselves. I was wondering if this is a fixable problem, I know laminators are super cheap but Im not at a point where I want to throw 30 bucks down on something that doesnt live up to my hope.I have plenty of nichrome and kanthal from vaping, toasters, dyres etc etc. If there anyway to get the heating elements going again or is this one of the those SOL problems since the elements are part of the rollers? maybe there is some diy super roller projects out there:

author: SeanB
author_rank: Super Contributor
timestamp: May 22, 2016, 05:08:37 pm
content: Picture of them, many I have seen have a pair of flat plates with the heaters in there, wound on a mica plate and then with a kapton insulator to heat the flat plate. Have had a few with a broken wire end, so just undo a turn and wind around the terminal again and they work again.
Need help identifying memory card connector on Lenovo X220 - Page 1
Forum section: electronics / repair

author: awe_cz
author_rank: Newbie
timestamp: May 17, 2016, 10:21:49 am
content: Hi,I have (mechanically) damaged card reader in my Lenovo X220. Unfortunately this part is soldered directly on motherboard so the only reasonable solution is to desolder it and replace. I'm not able to find any connector matching the pads;(This is how pcb looks like. There are two holes next to pads used for fixing the connector (plastic rods melted on the other side), then there is read/write sensor pad in bottom right part and on the right edge top and bottom are two pads just for fixing. The original connector had 18306 number on metal cover, no other sign/text there. I've seen some pictures of another X220 motherboards and they seem to be mounting more different types of connectors there - hard to say if they had equal pads though. Also, the original connector was push-push with card being hidden fully inside the chassis.Thanks in advance, I hope someone would know straight away;)

author: MrSlack
author_rank: Frequent Contributor
timestamp: May 17, 2016, 10:28:27 am
content: Damn that's on the motherboard on the X220. My X201 it's on a daughterboard which is cheap to replace.Can you get another X220 motherboard (dead) and steal the connector off it?

author: awe_cz
author_rank: Newbie
timestamp: May 17, 2016, 11:03:40 am
content: I was not able to find any, apparently they don't die that often. Apart from that, the connector itself is rather fragile and it might not survive it. It's made of some really soft plastic material that melts quite soon.I found image of another version od X220 motherboard, maybe this card slot rings a bell? Anyone is able to identify manufacturer?

author: Rasz
author_rank: Super Contributor
timestamp: May 19, 2016, 01:25:15 pm
content: Quote from: awe_cz on May 17, 2016, 11:03:40 amfew on ebay at ~$20 price pointalso this:http://allegro.pl/uszkodzona-brak-podsw-plyta-glowna-lenovo-x220-i5102171865.htmlhttp://allegro.pl/uszkodzona-brak-usb-plyta-glowna-lenovo-x220-i5102171837.html~$20btw those two are easily fixable, one has bad backlight, the other botched usb socked replacement, both come from same incompetent service place

author: awe_cz
author_rank: Newbie
timestamp: May 21, 2016, 09:32:13 pm
content: Quote from: Rasz on May 19, 2016, 01:25:15 pmNice find, thanks!
Digital clock unconnected resistor - Page 1
Forum section: electronics / repair

author: aljowen
author_rank: Newbie
timestamp: May 07, 2016, 05:37:42 pm
content: On my digital clock I noticed that the Temperature readout on it has been a couple deg c out for quite some time so I decided to open it up to see if it had any trimmer pots inside with the hopes of adjusting it, while I sadly didn't find any trimmer pots I did find this:I have never noticed an issue with the clocks functionality, Thatresistorcapacitor connects +3v directly to the switch, and the switch seems to works fine as is.So my question is, Do you guys reckon it was ever supposed to be connected on this configuration of the board?Some extra images just in case people are interested in them (its either oct 2004 or 2002, its stamped inside but the last digit is messed up) :

author: Neilm
author_rank: Super Contributor
timestamp: May 07, 2016, 05:46:44 pm
content: Are you sure that is a resistor? It looks more like a ceramic capacitor to me.

author: aljowen
author_rank: Newbie
timestamp: May 07, 2016, 05:51:12 pm
content: Yes, you are correct. Just tested it.Never done surface mount before and thought that they were resistors, my bad.

author: Raj
author_rank: Frequent Contributor
timestamp: May 21, 2016, 03:45:17 pm
content: looks like a button de bounce filter cap to me

author: Yansi
author_rank: Super Contributor
timestamp: May 21, 2016, 03:46:49 pm
content: Just solder the little bastard where it should be. The other pad is next to it. (Seems manufacturing defect and poor quality control in the manuf. process)

author: Raj
author_rank: Frequent Contributor
timestamp: May 21, 2016, 03:47:09 pm
content: I always say to myself... don't fix it unless it's broken
Identify part  - Page 1
Forum section: electronics / repair

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: May 20, 2016, 03:34:14 pm
content: Getting back to an earlier question , but could not find old post ?Trying to repair a inverter / charger Freedom Combi 2022 and found part of the protection circuit a diode was bad and 4 transistors that appear to control LED's , one was blown off board , one was moved / reflowed from too much current and the last 2 looked & tested ok , here picture .Trying to get info to order replacements ?

author: TiN
author_rank: Super Contributor
timestamp: May 20, 2016, 03:43:18 pm
content: Jelly-bean 2N7002 or it's analogue.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: May 20, 2016, 03:50:27 pm
content: Thanks , heading to our local Digi-Key to find .