hybridfree/eevblog-posts huggingface dataset:
Tektronix MSO3054 power supply trouble shooting - Page 1
Forum section: electronics / repair

author: hitecelec
author_rank: Regular Contributor
timestamp: June 11, 2021, 01:08:22 pm
content: Hineed help SMPS used in this scope is Emerson Network Power 7001526-J000 rev Adc voltages 12v 6.15 A, 6V- 6.15A, 5.1V 0.05Adoesnt power up in burst mode. on visual examination nothing burntAny cluesregards
Tektronix MSO4000B series - Page 1
Forum section: electronics / repair

author: ttbelectronics
author_rank: Contributor
timestamp: January 14, 2021, 10:51:31 pm
content: I have MSO4104B which front panel Keypad doesn't work, it boots pass self test but none of the keys work.Everything I check looks fine cannot find what is causing the problem.Anyone had experiences with this kind problem would like to share some information?Thanks.

author: ALLANDP
author_rank: Newbie
timestamp: July 16, 2021, 05:20:22 pm
content: Not sure on your repair but I just wanted to post if anyone needs to replace the encoders on their MSO4104B they are Bourns P/N: PEC12R-4020F-N0024. I just replaced the horizontal adjust encoder and it works perfectly!
Tektronix NetTek Analyzer - Touch Screen Fault - circuit diagram? - Page 1
Forum section: electronics / repair

author: HarryTek
author_rank: Newbie
timestamp: September 07, 2025, 09:20:38 pm
content: My NetTek spectrum analyzer (Y350C) has served me well until the touch screen just stopped working. It was working one day but the next day when I turned it on it was totally unresponsive - which makes the instrument useless!The analyzer display is based on a power PC running Windows CE. I have probed the circuit board and I can see that the touch screen itself is working and is being scanned. The touch output goes via an analog multiplexer to a 10-bit A/D converter.It is very difficult to trace and probe the signal paths, as there are many vias, and it is not possible to get to both sides of the circuit board when it is running.Can anyone help with a circuit diagram, there must be one somewhere?I have searched high and low but all I can find is the operating manuals. Not like with the old Tektronix equipment where everything is available.Any help will be gratefully received.

author: Jonny
author_rank: Regular Contributor
timestamp: September 13, 2025, 01:54:40 am
content: If it's resistive type touch screen, make sure there's no dirt between the housing and the screen as it can create pressure around the edge giving false touch responses. Also being windows, can you boot into a safe mode to see if it works again? Maybe it's software related.

author: HarryTek
author_rank: Newbie
timestamp: September 15, 2025, 01:54:03 pm
content: Thanks for your reply.It is a resistive type touch screen, and I did clean it, and its ribbon connector, before I started looking more closely at the hardware, but it made no difference.Windows CE does not have a safe boot mode, unlike XP and later versions of windows.I am pretty sure that it is a hardware problem. If I monitor the pins of the touch screen cable with a scope, there is no activity until the screen is touched.As soon as the screen is touched a scanning routine kicks off, resulting in the waveforms shown in the attached picture. (This is a composite picture showing the waveforms for the X and Y axis). When a finger is dragged across the screen the X and Y traces can be seen to change.The problem seems to lie in a faulty analogue multiplexer chip, which should send the signals to an A/D, but they do not make it that far. I have ordered a replacement part and will update the post when I have tested it.
Tektronix option code Generation - Page 1
Forum section: electronics / repair

author: tektronixman
author_rank: Newbie
timestamp: March 06, 2023, 11:08:19 pm
content: Does any body know how Tek used to generate these codes I believe they were used on various Tek test equipment. Tektronix have no interest and no record of how it was done but is there any body who used to work for Tektronix who would be able the shed some light on the process Who knows it may be possible to start generating some and rescue some of the fantastic kit like the VM700 sRegards all Colin
Tektronix Oscilloscope TDS7154 On/standby switch not working - Page 1
Forum section: electronics / repair

author: joonse
author_rank: Newbie
timestamp: June 29, 2025, 10:41:13 am
content: Hello everyone,I’m reaching out with a question regarding the power-on switch of the Tektronix TDS7154 oscilloscope.Even though the rear power switch is enabled, pressing the front panel power button results in no response at all.As part of the repair attempt, I disassembled the unit and cleaned the front panel area with IPA, and even tried applying graphite using a pencil to restore conductivity — unfortunately, this didn’t resolve the issue.I also traced the flex cable coming from what appears to be the capacitive touchpad, and attempted to simulate a button press by shorting pairs of the 5 pins(not sure) in various combinations, but again, nothing happened — no signs of life.Referring to the manual (see attached photo #3), I tried jumping the debug power-on pin, and while this did cause the system to power up, it didn’t boot properly:all front panel buttons lit up, but the screen remained black, and the oscilloscope never fully initialized. (I'm unsure if this behavior is expected when using the debug power-on pin.)At this point, I’m wondering — what else can I try?Any insights or suggestions would be greatly appreciated.Thank you in advance for your help!

author: EduardGede
author_rank: Newbie
timestamp: July 24, 2025, 05:01:13 pm
content: Hi,The flex in your unit is old and of poor quality.Look for this topic "Tektronix on/off powerflex TDS5/6/7/8000 series partnumber 259-0155-01"https://www.eevblog.com/forum/buysellwanted/tektronix-onoff-powerflex-tds5678000-series-partnumber-259-0155-01/Gede

author: coromonadalix
author_rank: Super Contributor
timestamp: July 24, 2025, 07:31:45 pm
content: lucky youcheck the sell section thread ... as he wrote loll

author: joonse
author_rank: Newbie
timestamp: July 24, 2025, 08:41:19 pm
content: Thanks for replies !I will try to buy the part ^^
Tektronix P5050 shorted cable - Page 1
Forum section: electronics / repair

author: Jwalling
author_rank: Unknown
timestamp: February 10, 2021, 12:59:14 pm
content: Never seen a scope probe cable fail shorted before. Open, yeah, all the time...About 550 Ohms.Might try blowing the short with a power supply, but I'd worry about it coming back again in the future. I wonder if it could be a tin whisker thing?

author: capt bullshot
author_rank: Super Contributor
timestamp: February 10, 2021, 01:16:55 pm
content: I've had this before, too. And it was reported by someone else before, tin whiskers were suspected. Goes away by applying some voltage.When I tried to use that particular probe (indeed a bunch of probes were affected), I was quite confused until I discovered the short.

author: CaptDon
author_rank: Super Contributor
timestamp: February 10, 2021, 02:16:25 pm
content: With the insane price that Tek charged for those 500mhz probes back in the day they sure didn't hold up very well. The grounding was always suspect when the probe lead could twirl around in the body of the 10:1 part that attached to the scope. The little trimmer capacitors were easily damaged when doing compensation adjustments also. What about the crappy probe that was 6mhz in the 1:1 mode and 100mhz in the 10:1 mode!!!! Are you kidding, 6mhz in the 1:1 mode?I have probes from old 10mhz scopes that will do 50mhz faithfully without over/undershoot and ringing. And the crappy low bandwidth probe from Tek was still around $170.
tektronix p5122 probe (blue one) - compensation stoped working - Page 1
Forum section: electronics / repair

author: zoiasso
author_rank: Contributor
timestamp: April 20, 2021, 02:02:34 am
content: Anyone knows how to open the bnc conector of this probe wtihout damaging it? The balance adjustment stopped working, i think the variable capacitor lost connection. Im a electronics hobbiest only, i got this one used for cheap with all acessories, i was adjusting the compensation and suddenly it stopped.

author: zoiasso
author_rank: Contributor
timestamp: April 20, 2021, 02:09:56 am
content: managed to open the back, just need to know how to remove the spring part now.

author: zoiasso
author_rank: Contributor
timestamp: May 11, 2021, 12:59:44 pm
content: up
Tektronix P6117 passive probe repair (THS720) - Page 1
Forum section: electronics / repair

author: Caaarlo
author_rank: Newbie
timestamp: September 05, 2019, 03:05:06 am
content: After receiving an 8KV pulse (accidentally) during a measurement, not only the probe is broken, but also one of the input attenuator boards.The Probe is mostly fine, except for the input chip resistor which actually has the resistive film (laser etched) on one side and an integrated capacitor in the other side of the ceramic substrate. The attached images show the resistor next to a 1206 SMD 000 jumper for size reference.Well, the capacitor blew up (see the crater on the red paint) and left the resistor alone without compensation cap, leading the -3dB frequency to shrink from the original 200MHz to ~10KHZ, so I have two choices:1) To solder an SMD capacitor (probably ~10 pF) in parallel with the resistor2) To get a spare resistor-capacitor chip(and possibly a third choice: To buy a new probe)The resistor-capacitor chip seems to be a custom part, nearly impossible to source.Suggestions ?

author: Gyro
author_rank: Super Contributor
timestamp: September 05, 2019, 10:55:37 am
content: It looks dead unless you can source a replacement custom R/C unit.It's that size of distributed R/C for a reason. You won't achieve the same performance or ratings by just hacking some SmD Rs and Cs together.

author: macboy
author_rank: Super Contributor
timestamp: September 06, 2019, 01:13:39 pm
content: Save this link:https://www.tek.com/datasheet/passive-and-active-probe-general-replacement-partsFor Tektronix subminiature probes (2.5mm and 3.5mm size), this hybrid is part of the replaceable probe tip (refer to photo halfway down the above linked page). In the manual for your probe, it isn't clear where this hybrid is located or whether it is included with the replacement tip part number 131–4997–01. I would assume not. The hybrid is also not listed as a separately replaceable item.You may get lucky and find a used probe with a damaged cable or some other defect that makes it inexpensive. Hopefully then you can salvage parts from it to fix yours. Also be sure to carefully check all components in the compensation box of your damaged probe.

author: Caaarlo
author_rank: Newbie
timestamp: September 08, 2019, 12:22:06 am
content: Quote from: macboy on September 06, 2019, 01:13:39 pmThank you ! Unfortunately, the R-C hybrid is not within the tip, but soldered on a thin pcb inside the probe body. I think I will try adding an SMD cap and see how it goes.
Tektronix PowerPc in tds7xxx series monitor connection - Page 1
Forum section: electronics / repair

author: charlyd
author_rank: Frequent Contributor
timestamp: December 27, 2020, 06:37:06 pm
content: Hi i am working on a 7000 series scope (see other topic) i open this topic because i am curious if everyone ever diagnosed the monitor( &touch) connector on the PowerPC board in the Tek 7000 seriesFrom what i found the display is a 640x480 TTL analog RGB signal. a NEC 104BLM31 also know as a NL6448BC33-29 i am looking to find a 10.4" 1024x768 screen.if not possible directly then i will figure out to the vga output on the pc board.but i first want to o for the internal version so then i came to the connector situated on the PowerPc board right behind the display where the lcd flatcable ends.does somebody ever managed to get the pinout from that connector.?i am curious to that pin out og theJ190...

author: m k
author_rank: Super Contributor
timestamp: December 29, 2020, 05:58:05 pm
content: Does the machine support those new pixels?If not then you still have those 640x480 pixels in your new 1024x768 screen.One manual says that internal LCD resolution must be 640x480 and 16bit colors.It succests that connector is something parallel.You can test it but for that you probably need a more than mechanical adapter, since it's rather irritable if you must open and close the machine all the time.

author: charlyd
author_rank: Frequent Contributor
timestamp: January 03, 2021, 02:44:45 pm
content: Hi M K i think you are right the resolution is ok but it is the colordepth where it goes wrong and i looked to the SVGA output (ati rage 3D) which is for sure a higher res. and colordepth. so i think i am going to work out if i can fit in a 1024x768 10.4" led with USB touch.come back on this one later.Is there anybody who already tried this conversion?
TEKTRONIX PS 5004 diagrams - Page 1
Forum section: electronics / repair

author: roumen
author_rank: Newbie
timestamp: April 13, 2020, 03:09:44 pm
content: Hello,Looking for diagrams only to repair my Tektronix PS 5004 Precision Power Supply.Instruction Manual 070-4442-00 is available but diagrams missing.Regards / RoumenLZ3RV

author: anotherlin
author_rank: Frequent Contributor
timestamp: April 13, 2020, 06:49:33 pm
content: Hi,Seems that the manual with full schematics isn't available on the web.Try artek media, they have full scan of the manual.Unfortunately, it's not free ($10), but the scans are very good quality.Best regards,

author: duak
author_rank: Super Contributor
timestamp: April 13, 2020, 08:30:24 pm
content: I was interested to see the details but could not find a schematic either. The best I could do was a more detailed block diagram.

author: roumen
author_rank: Newbie
timestamp: April 13, 2020, 11:58:04 pm
content: Dear Anotherlin and Duak,Thank you very much for your response.I will ask ArtekManuals.Best regards
Tektronix PS2520G - Torn binding post mounting trace - Page 1
Forum section: electronics / repair

author: amaschas
author_rank: Regular Contributor
timestamp: August 25, 2025, 03:42:28 am
content: I recently acquired a Tektronix PS2520G that had an inconsistent power output on channel 1, and after disassembly I discovered that one of the binding posts had torn traces free from the mounting PCB. I've repairing ripped traces before on a number of boards, usually by either adding some trace area with copper tape and UV-curable PCB coating or just bridging in a wire from a nearly point, but in this case the solder connection is structural and I'm not sure how exactly to proceed. I think the other binding posts appear to have some sort of adhesive coating over the solder joint, so I'm thinking I can use my standard copper tape approach and add a final coat of epoxy? Curious if anyone has attempting a similar repair successfully.
Tektronix PWS2185 Schematic - Page 1
Forum section: electronics / repair

author: jseefried
author_rank: Newbie
timestamp: May 18, 2023, 02:44:42 pm
content: Hello all,Does anyone have a service manual or at least the schematic for the Tektronix PWS series power supplies? Specifically the PWS-2185?If so please email me: jseefried@reagan.comThank you.
Tektronix RM502A Scope Repair - Page 1
Forum section: electronics / repair

author: Lem
author_rank: Newbie
timestamp: August 30, 2020, 02:26:59 pm
content: HiI have this Tek RM502A scope that has a single sweep problem.When set to do single sweep....as soon as the scope triggers the ready led goes off, the actual waveform displays for a split second and disappears.So when single sweep is reset led comes on (ready for sweep) then as soon as its triggered the led goes off and the waveform is displayed for a split second then disappear.Does some of you guys maybe know what could cause this?PS: Normal sweep mode seems to work fineThanksRichard

author: bob91343
author_rank: Super Contributor
timestamp: August 30, 2020, 09:36:29 pm
content: It's totally normal. Single sweep is just that - the trace triggers and waits. So unless your CRT has infinite persistence, it is to be expected that it will fade out quickly.You would want a storage scope to get the trace to be displated after the spot is cut off.

author: Lem
author_rank: Newbie
timestamp: August 30, 2020, 10:02:18 pm
content: Yes just discovered thatFeel Like an idiotI have the 468 storage scope that can do storage.Apparently that single sweep of the 502 is used with a cameraBut thank you. It is good to know that it works the way it is suppose toThank you Vince For the info
Tektronix SC502 scope brightness drifts - Page 1
Forum section: electronics / repair

author: CaptDon
author_rank: Super Contributor
timestamp: December 09, 2021, 01:38:38 am
content: I have an SC502 15mhz analog scope (the modular series) and the brightness drifts. I noticed the comparator circuit made up of Q830 and Q820 is very temperature sensitive. I have tried freeze spray on all the different components in the circuit and none cause brightness drift EXCEPT the comparator transistor pair. I have physically bent them to touch each other and JB Welded them to each other. The reason I did that is heating one makes the brightness go up, heating the other makes the brightness go down so I tried to thermally bond them to neutralize the effect of temperature drift. It is better by a 'relative' eyeball quality factor of 50% less brightness drift, but it still has some drift. Anyone familiar with this anomaly? I had several SC502's in various workplaces and I don't recall this much drift. Thanks for any leads!!

author: ESTechnical
author_rank: Contributor
timestamp: December 09, 2021, 08:32:22 am
content: Is the comparator just a long tailed pair? If the output is single-ended, is the load on the output perhaps higher than before leading to one transistor being too hot? Maybe the gain of one transistor has become very different to the other one? Is the supply voltage well regulated to this part of the scope circuit or is that drifting too?

author: CaptDon
author_rank: Super Contributor
timestamp: December 09, 2021, 03:10:30 pm
content: both of the comparator bases are connected to +5 regulated via resistors and the commoned emitters are connected to +20 regulated via 7.68k. Q830 has its base driven from the intensity control which itself is a low voltage circuit, basically a pot connected from ground to +5 regulated, not high negative cathode voltage. Q820 is the other side of the comparator and its base is driven by the sweep unblanking signal, the chop signal when in dual trace chop mode, and external rear panel Z-Axis input which is unconnected. All voltages are correct and well regulated as is the high voltage. There is no blooming or defocusing and the C.R.T. is very sharp and bright as if it were new. The resistor values connected to the transistors are of high enough value that nothing is dissipating more than 10 to 20 milliwatts. When first turned on the trace is very bright, then it settles down to a 'normal' level during perhaps a 5 to 10 minute 'settling' period. I leave the intensity control alone knowing it will finally stabilize where I want it.
Tektronix Scope Shopping Cart List for replacement parts 465 465B 2246 2465B - Page 1
Forum section: electronics / repair

author: W3KW
author_rank: Contributor
timestamp: December 12, 2022, 09:22:21 pm
content: I own a 2235, 465, 465B, 2246, and 2465B Tek scope. I am gearing up to service them over the winter and found a great way to get the required parts gathered more easily. I watched this videohttps://youtu.be/lrXCVg6T-ekon the 2235 and in the comments was an entire parts list for a Digikey shopping cart. I opened the link which took me to MY shopping cart. I made a few changes for parts that were back-ordered, and bam. Done. Wow. That was easy.Does anyone have a shopping list for the other scopes you may have used recently? The electrolytic versus tantalum issue is interesting. Does anyone have input on that issue? Are modern tantalum caps dependable?I searched the forums pretty hard for this topic (a shopping list) and didn't see an obvious answer or resource. If I missed it, please point me in the right direction.Thanks all,WesW3KW

author: med6753
author_rank: Super Contributor
timestamp: December 13, 2022, 02:39:11 am
content: If your intention is to re-cap the PSU in the 2465B you will find this link helpful:https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/msg1658102/#msg1658102The list of capacitors required is attached.Modern tantalum capacitors appear to be much more reliable. That said replacing all the tantalums in the 465/465B would be an extremely expensive and time consuming proposition. In my experience with 400 series scopes there seems to be a pattern that 15uf and above with especially the 47uf tantalums to be the most troublesome. Concentrate on those values and stick with no lower than 35V.I've done PSU capacitor replacement on both the 465 and 465B but I don't have a saved material list. I also used the capacitor mounting adapters readily available on Ebay.I've also done a 2235 but the YT link you found is perfect. I have no experience with the 2246.
[EDITED] Reverse engineering a transformer without knowing all secondary turns - Page 1
Forum section: electronics / repair

author: gkmaia
author_rank: Frequent Contributor
timestamp: September 21, 2019, 10:59:57 pm
content: Edit: subject and basic informationThis may be a long shot.I have a high voltage switching ferrite transformer that has failed. Due to the construction of the transformer I could not retrieve all its windings. The only winding I could retrieve was the primary.The oscillation is caused by the feedback winding forward biasing a transistor at the end of the primary winding.Is it possible to recalculate the secondary windings taking in consideration:- cylindrical core area 80mm2- operates at 50Khz- ferrite Bsat ~0.3T- primary (pin 4-5) has 30 turns. Is feed with rectified/decoupled +120VDC oscillates at 240v pk-pk.- feedback (pin 3-6) is feed with rectified/decoupled +2.3VDC oscillates at 4.5v pk-pk- secondary A - (pin 9-10) oscillates at 2v pk-pk- secondary B pin 1 ground- secondary B pin 2 -120VDC from rectified/decoupled input- secondary B pin 7 -220VDC from rectified/decoupled input- secondary B pin 8 -2.7KV RMS supply to CRTRegarding the current I can still retrieve the winding gauges.

author: Chris56000
author_rank: Frequent Contributor
timestamp: September 22, 2019, 07:38:18 pm
content: Hi!Try heating the transformer with a heat-gun - this might soften the resin enough to enable you to chip it away so you can get at the remainder of the windings!Failing that, you might find one of the other Tektronix oscilloscopes that uses a similar type of e.h.t. oscillator has a transformer you can use in your T910 with a little circuit adaption!Chris Williams

author: gkmaia
author_rank: Frequent Contributor
timestamp: September 22, 2019, 07:57:53 pm
content: Heating did not work... unfortunately.But I guess that could be a cool project. Trying to figure out what the other windings are based on the primary and the schematics.Not sure if that is possible. But would be a cool project if it is.

author: andy3055
author_rank: Super Contributor
timestamp: September 23, 2019, 11:07:14 pm
content: Unless you took the transformer out of the board or lifted other parts to isolate it, you could be reading through other components and the readings will throw you off.I am, at the moment, repairing my 465M and found the issue was the tripler. I had to isolate it before I was able to stop the fuse from blowing. I was glad to find that the transformer is OK.Try these guys:https://www.sphere.bc.ca/test/tek-transformers.html#catalogEven if they have not listed it, they may be still having one in their pile of stuff in the back! The site also shows a couple of them that has clips holding the 2 halves of the ferrite core together. If you break the ferrite core you are dead! If you drop it, it is gone. I am saying this not to insult your knowledge but because it is very brittle, delicate and fragile. So, be very gentle with it.Good luck
Tektronix TAS 250 +145 V power supply repair and partial schematic - Page 1
Forum section: electronics / repair

author: octillion
author_rank: Contributor
timestamp: January 03, 2021, 01:48:02 am
content: I fixed an issue with an out-of-spec +145 VDC supply in a Tektronix TAS 250, which I'll share here in case it helps anyone else. A service manual, schematics, and BOM were never released for this or the sister TAS 220, only adjustment procedures.It's a budget scope, I wouldn't ever pay money for one (I found it in the trash), but functions well enough for most uses once it is working and tuned up. The plastic used to make the knobs is absolute garbage, and will spontaneously fall apart without ever being touched. If you want to have a laugh, do an image search for TAS220 or TAS250, and notice that 99% of the images have at least one knob missing or replaced with a substitute. This guy made 3D printed knobs for the variable knobs, and released the design files:https://www.thingiverse.com/thing:2209012I was making replica knobs for a few other items, so ended up making all new knobs for this oscilloscope. Attached are one of the few TAS 250 images with zero missing knobs, but they are all replicas (only the buttons are original, which don't spontaneously disintegrate). The knobs are a little darker than original as I was color matching for the other knobs I was making.Symptoms:The screen intensity was too high, and the beam retrace was visible (especially at the fastest time divisions). At 0.1 us/Div, the main beam and retrace had equal brightness, making it hard hard to distinguish the two, and the image would distort when moving the horizontal position left and right. At the fastest time divisions, the cursor display had a significant amount of noise. Focus and astigmatism were sub-optimal, but not bad.Resolution:Replaced C605 (1 uF 200 V), which was leaky and caused the +145 V supply to regulate around 130 V.Casual inspection of C605 could easily miss this fault, as an LCR meter measured 0.974 uF with a Q of 25 at 120 Hz. DC resistance measured with a DMM fluctuated between 12.5 - 13.5 MOhm, but when measuring leakage current at high voltage, the DCR dropped below 1 MOhm, which is sufficiently low to bring the circuit out of spec.Circuit notes:Partial schematic attached. A bridge rectifier charges a 47 uF 350 V capacitor to about 210 volts (this is not shown in the schematic, but it connects to the double up and double down arrows). The positive end is the +145 V supply rail, and the negative end gets regulated through Q601 to ground, referencing the -12 V supply.
Tektronix TCP0030 Probe "Overload" condition after 20 min warmup - Page 1
Forum section: electronics / repair

author: dominitech
author_rank: Contributor
timestamp: February 04, 2022, 06:59:39 pm
content: I have a Tektronix TCP0030 current probe that will have an "Overload" fault after warming up. I took the compensation assembly apart but could not visually find any problems with it. I inspected the probe head itself as well. I am wondering if anybody knows of the fix for this specific problem. Tektronix no longer sells the parts for these and probably not worth it to spend too much time troubleshooting it but the customer still wants it fixed of course. Any help is appreciated, thanks!

author: mikehank
author_rank: Regular Contributor
timestamp: March 18, 2022, 03:53:44 pm
content: You most likely have a bad hall effect device. I dont think sells those out anymore so ya its probably scrap.

author: dominitech
author_rank: Contributor
timestamp: March 22, 2022, 04:34:48 pm
content: Quote from: mikehank on March 18, 2022, 03:53:44 pmThanks, yeah I ended up sending it back as is but now I know not to accept these in the future for this problem.
TEKTRONIX TDS 1002: HELP! - Page 1
Forum section: electronics / repair

author: lionelkjh
author_rank: Frequent Contributor
timestamp: November 07, 2022, 04:22:10 pm
content: Hi there! Since this morning; my trusty TEKTRONIX TDS 1002 oscilloscope is down with the following error at startup: CH1 and CH2 acquisition down; without any apparent reason, because it worked perfectly the day before!! Has anyone ever faced this failure? Is it fixable??? Thanks for your help!

author: alm
author_rank: Super Contributor
timestamp: November 10, 2022, 05:16:52 pm
content: Quote from: lionelkjh on November 07, 2022, 04:22:10 pmMaybe. Start with collecting all service documentation you can find for it. You won't find any schematics, but if you're lucky you might find a service manual with a block diagram and some other details.If you can do it safely, I would start by measuring the power rails, both DCV voltage and ripple. Ideally, if you have access to another scope, check them with a scope. I would also try reseating any internal connectors, especially if there's a cable between the digital board and the acquisition board (and if these are separate boards). Take pictures, and check for any burnt component on the PCB.
Tektronix TDS 2012 display issues - Page 1
Forum section: electronics / repair

author: s-petersen
author_rank: Contributor
timestamp: April 08, 2025, 08:10:00 pm
content: I bought a TDS2012 on ebay for cheap, and when I received it the LCD had a few small vertical lines in it, and the rotary encoder for CH1 Volts/Div had broken plastic rivets holding it to the control board. It was basically usable for my needs, after an hour I shut it down, and the next time I turned it on, the screen image was shifted to the left 1.25" but was otherwise ok, well it seems every time I turn it on, the LCD reacts differently. The issue does not seem heat related (maybe works a little more reliably when warm), and is also not affected by jostling it around.After this happened, I repaired the rotary encoder, I completely disassembled the LCD, and didn't see anything out of the ordinary, and reassembled the scope, nothing changed with the LCD. What could be casing this? It does not seem like bond failure, and it is erratic, and not a constant issue, sometimes it will work properly. What ever it is, is related to initializing the LCD, because it will not change until it is shut down, and restarted. If the picture is good, it will stay that way, for as long as you keep it powered up.

author: s-petersen
author_rank: Contributor
timestamp: April 10, 2025, 04:08:50 pm
content: So yesterday, it worked well all day, and today I got this. It seems random, Is this possibly a PS noise problem, LCD problem(cap?) or motherboard problem? Any way to isolate it? Any ideas?

author: ondraN
author_rank: Regular Contributor
timestamp: April 10, 2025, 04:53:42 pm
content: I solved a very similar problem on another DSO and it was caused by a faulty RAM for the display. It could be detected by applying "Freeze spray" to individual circuits. Before that, of course, check the PSU and noise on the power lines.

author: s-petersen
author_rank: Contributor
timestamp: April 16, 2025, 05:01:29 pm
content: Is the ram directly on the LCD board, or the main board?I just repaired another o-scope, a FNIRSI 1014D it works mostly, the function generator is still dead, but it should be good enough to scope the PS, will do. Thanks!
Tektronix TDS 2012B,just backlight and nothing on the display. - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: December 29, 2021, 12:33:42 pm
content: Hi all ive the chance of one Tektronix TDS 2012B scope that fires up to a totaly blank display,ie backlight comes on but a blank screen,is it likley to be fixable or do i leave it?

author: george.b
author_rank: Frequent Contributor
timestamp: December 29, 2021, 04:30:01 pm
content: Is there any signal on the probe compensator output?

author: Squarewave
author_rank: Frequent Contributor
timestamp: December 30, 2021, 04:19:45 pm
content: Is this the one on ebay? I saw that one too, if it is that one. Let us know how you get on if you do get it.

author: m3vuv
author_rank: Super Contributor
timestamp: January 01, 2022, 01:26:47 pm
content: yes its on fleabay beeing sold by freespirit,i got outbid so left it,i just got a tek2430 that ive repaired,i now have 5 scopes,an old 453 50mhz bw,a kenwood DCS-8200 dso 50mhz bw,an hp 54503a 500mhz bw dso,and an old heath pc scope 50mhz bw so dont realy need any more,unless i can find one with a higher sampling depth cheap lol.

author: m3vuv
author_rank: Super Contributor
timestamp: January 01, 2022, 01:28:04 pm
content: out of all my scopes the old 453 is my goto scope,lovely to use compared to the dso scopes.
Tektronix TDS 3032B - Dead power supply - Page 1
Forum section: electronics / repair

author: Arca
author_rank: Newbie
timestamp: March 21, 2021, 10:45:33 am
content: Hello all,I picked up a broken Tektronix TDS 3032B.PSU is dead on it (NFN40-7615N01 -https://docs.rs-online.com/f3f9/0900766b800a6f33.pdf). Some componant are dead (red on the picture) :It seems that some componant had already been replaced in the past. There is also componants that I cannot identify (burned resistor for example), so I'm thinking about replacing all the PSU board by a new one, and not just replace dead componants (there is probably more dead componants than what is visible).What reference could be compatible? The one that is used no longer exists.Artesyn LPS64 could be fine ?https://docs.rs-online.com/34b4/0900766b814344f9.pdfThx

author: giosif
author_rank: Frequent Contributor
timestamp: March 25, 2021, 09:41:06 pm
content: From the perspective of electrical specifications, I think LPS64 should be fine.Even from the physical dimensions, it is ok, except for the height: it is about 1.0 cm taller than the original power supply.Whether that extra height is an issue or not, I cannot say for sure, but I think it might interfere with the module plastic tray which normally sits above the PSU.The other concern is the height of the heatsink and capacitors at the end of the board on the secondary side of the PSU, which might interfere with the board which has the Ethernet port (among other things).I suggest putting the dead PSU back in the scope and put everything together, including the module plastic tray, but except for the rear case.Then, check for clearance between the PSU and the surrounding elements.If you have 1.0 cm or more of clearance, you are good with the LPS64.

author: Arca
author_rank: Newbie
timestamp: March 27, 2021, 09:01:27 am
content: Thanks a lot for your answer ! 😄I'll check dimensions when I have a bit of time.I'll give a feedback then.

author: Arca
author_rank: Newbie
timestamp: April 04, 2021, 09:58:47 am
content: Hello,I'm about to order the board but yeah, LPS64 is a bit high and also expensive.I found LPS44 with similar specs, less high and less expensive :https://fr.rs-online.com/web/p/alimentations-a-decoupage/1829997/If I'm not wrong, it should work.I also found a low cost one :https://fr.rs-online.com/web/p/alimentations-a-decoupage/0200055/I guess the output connector is different but if I adapt it, could it work ?Thx

author: giosif
author_rank: Frequent Contributor
timestamp: April 04, 2021, 11:11:48 am
content: The LPS44 looks to be an exact match, both electrically (in terms of output specs) and physically.I didn't check the low-cost PSU, but I wouldn't risk the rest of the scope by going cheap on the power supply.Good luck!
tektronix TDS 3034B - Page 1
Forum section: electronics / repair

author: hitecelec
author_rank: Regular Contributor
timestamp: October 15, 2024, 08:48:47 am
content: helloHow does one clean the rotary encoders/switches of the scopeVolts/div, Time/div etcThanks in advance

author: sicco
author_rank: Regular Contributor
timestamp: October 15, 2024, 06:51:12 pm
content: Many hints here:https://www.eevblog.com/forum/repair/tds3000b-tds3054b-strange-type-rotary-encoder-repairreplacement/msg2825664/#msg2825664andhttps://www.eevblog.com/forum/testgear/tds3000b-tds3054b-rotary-encoder-repairreplacement/msg3578292/#msg3578292

author: coromonadalix
author_rank: Super Contributor
timestamp: October 15, 2024, 11:24:51 pm
content: i would have used a small twist drill make 2 small holes, 1 near each plastic post who pass thru the pcbon the other linked thread you see how the pcb pads are ... just drill location when the circular pads are not under the square framei first would not decap theses from the pcb, but try cleanup before anything else

author: hitecelec
author_rank: Regular Contributor
timestamp: October 16, 2024, 12:15:02 pm
content: hellothanks for all the inputs
Tektronix TDS 3052B stuck on splash screen - Page 1
Forum section: electronics / repair

author: djcrazeed
author_rank: Newbie
timestamp: March 12, 2022, 01:43:23 am
content: Hello all! I thought I might see if anyone on the forum has successfully repaired one of these units. I understand this is a fairly common problem with these scopes and have read a few entries here regarding this problem but I don't think I've seen any where the scope was brought back to life. I've got a TDS 3052B that is stuck at splash screen. No relay click, nothing, just splash screen. Inside there are no blown components, power supply is working well. i thought I might take a chance and pull out the timekeeping ram to replace but that would be a shot in the dark. Is there a way to test the ds1742 to see if the battery is indeed dead? Date code on mine is 2006 so it could certainly be older but still could be dead. Any and all ideas are welcome, Thanks!!

author: dominitech
author_rank: Contributor
timestamp: March 12, 2022, 06:16:52 am
content: Quote from: djcrazeed on March 12, 2022, 01:43:23 amYes, I have fixed a TDS 3054 before that would not boot up. They don't sell the exact part anymore but you can find a modified one that is sold on eBay herehttps://www.ebay.com/itm/293776182478.2006 is pretty old and I don't see many batteries go past 10 years so its something you'd want to change anyway.

author: m3vuv
author_rank: Super Contributor
timestamp: March 12, 2022, 10:22:38 am
content: Are they taking the piss with pricing?

author: Teichhermelin
author_rank: Regular Contributor
timestamp: March 12, 2022, 10:43:41 am
content: I had the same Problem. I have payed 40€ for the Battery

author: djcrazeed
author_rank: Newbie
timestamp: March 12, 2022, 11:37:24 pm
content: Ha! As it happens I was looking at that exact ad last week and decided that if it came to it, that would be the one I would buy. I was corresponding with the seller and he told me how the scope should behave with the nvram out completely so I've got that for troubleshooting. I think I'll take a chance and pull the nvram, haven't got much to lose at this point. Thanks!!

author: djcrazeed
author_rank: Newbie
timestamp: March 12, 2022, 11:39:37 pm
content: Did it fix your problem?
Tektronix TDS 310 repair help - Page 1
Forum section: electronics / repair

author: Helios
author_rank: Newbie
timestamp: June 30, 2020, 08:29:19 pm
content: I have some problems with my Tektronix TDS 310 and unfortunately the other TDS-related threads on the forum did not help me enough to fix it.The scope boots up fine and passes the powerup checks but the Cal. initialisation fails. I have attached the error log for further information.All measurements are fine up to 100mV/div except for some offset between ranges. When switching into <100mV/div the input signal is gone on both channels. I have read that there can be some problems with the relays on the input but I could not notice anything abnormal (coil voltage, contact resistance etc.).The only fault I was able to find is the input resistance. When the range is >50mV/div, the resistance is 1 Meg on both channels. When switching to 50mV/div, the respective relay clicks and there is a voltage of 6.7V on the input BNC. What could be the cause of this and how could I fix it? Bad/leaky caps perhaps? Any help is greatly appreciated.

author: wn1fju
author_rank: Frequent Contributor
timestamp: July 01, 2020, 10:18:20 pm
content: I have a TDS350 which is similar and the problems I had were similar to yours: 1) the baselines would shift around, 2) the traces would vanish off the screen at 50 mV/div and below, and 3) there was approximately 7 volts on the input BNC connector. Incidentally, as soon as I put a load on the BNC, the 7 volts dropped way down. All this happened only on channel #2 in my scope.My conclusion - and I know this isn't good news - was that the input preamp hybrid was bad. I managed to find one fairly cheap on eBay and that fixed the problem. The hybrid doesn't look like a circuit that is easy to repair - there is all sorts of buried stuff if I recall. Perhaps someone else on the forum that has actually fixed one successfully can chime in.

author: Helios
author_rank: Newbie
timestamp: July 04, 2020, 09:14:36 am
content: I will try to do some measurements on the preamp circuit. Replacing its components sure does look quite tricky. I guess someone must have overloaded ch1 and then continued to ch2 since both channels are affected.Thanks for narrowing down the problem!
Tektronix TDS 340 help - Page 1
Forum section: electronics / repair

author: aqibi2000
author_rank: Regular Contributor
timestamp: June 24, 2020, 07:42:28 pm
content: I’ve scored this scope cheapAnd was told it was dead, as it arrived I dissembled and checked all unlit stages for shorts and the input high wattage power resistorsIt turned on to my joy, but it’s not working correctly1) When power is inserted all the buttons illuminate and the screen stays off, I press the power button and the unit boots up and passes all test, yet I cannot turn it off from the same switch?2) the 2 reference signals are always displayed, how does one turn these off permanently - maybe the Coin cell battery needs replacing3) the signal is very noisyI know these can do with RECAP but I’d like to see what other failures may be on the cardsPoor photo looks like it’s a long exposure photo

author: Smoky
author_rank: Frequent Contributor
timestamp: June 24, 2020, 08:08:26 pm
content: The first thing I would do is pop the grille off of the front of the scope. Remove the rubber membrane that holds the carbon contacts for the soft-buttons. Put it in a container of hot water and dish-washing soap. Scrub it with a toothbrush, rinse, and pat it dry.Look closely at the carbon buttons in the membrane, if you see a silhouette or shadow on them, lightly swipe the face of them with a piece of 2000 grit or higher wet/dry sandpaper to remove the glazing.Next, take a soft dampened cloth and lightly wipe over the contacts taped to the chassis of the oscilloscope. Don't use alcohol or any other solvent to do this.The same needs to be done to the membrane behind the front panel board since there are soft-buttons that select/remove the waveforms. I've seen electrolyte eat the traces to the contacts and make the switch inoperable.

author: aqibi2000
author_rank: Regular Contributor
timestamp: June 24, 2020, 08:28:15 pm
content: I think you’re right. I thought I was powering it up but instead it’s auto booting up after about 30’ seconds of power.Every button currently works on the front membrane so need to give the power button and ribbons some attention.Also the noise signal was actual noise over the cables from my function gen ha haThank you I’ll feedback after doing what you suggested to the entire unit
Tektronix TDS 420 Oscilloscope and SMPS repairs - Page 1
Forum section: electronics / repair

author: Shock
author_rank: Super Contributor
timestamp: April 21, 2016, 05:22:19 pm
content: Enjoyed these so shared.

author: maxxim
author_rank: Contributor
timestamp: January 11, 2020, 06:11:24 pm
content: hello everyone, what is the value of the tantalum capacitor on the underside power supply pcb (hybrid pin 13-19)
Tektronix tds 460A PSU  - Page 1
Forum section: electronics / repair

author: vectra_1098
author_rank: Newbie
timestamp: April 10, 2019, 10:39:19 am
content: Hi ,I have another Tektronix Scope a TDS 460A with a failed power supply.Does anybody have any schematics/pcb layouts for this PSU ??Thanks in advance...

author: pbarton
author_rank: Frequent Contributor
timestamp: April 10, 2019, 09:56:24 pm
content: Some info herehttps://www.eevblog.com/forum/repair/tds400-power-supply/msg2138764/#msg2138764

author: Dacke
author_rank: Regular Contributor
timestamp: April 11, 2019, 12:05:00 am
content: There isn't really schematics available for the TDS *** scopes as far as I know. When I rebuilt my TDS 420's power supply I used the schematic for a Lecroy 9354A power supply, it is about 90% the same power supply, you just have to be aware of the differences. I'm not sure if the TDS 460 has a similar supply to the 420, but a link is here:http://bee.mif.pg.gda.pl/ciasteczkowypotwor/LeCroy/LeCroy_9354A-M-L-TM_Service_Manual_Complete.pdf- pages 8-195 and 8-196.

author: shakalnokturn
author_rank: Super Contributor
timestamp: April 11, 2019, 11:40:49 am
content: Is it the PS-1690 model you have?

author: vectra_1098
author_rank: Newbie
timestamp: April 11, 2019, 05:10:46 pm
content: Hi,The PSU has a TEK number on the top silkTEK 119-3939-02I tried to send a jpeg photo but the site failed to send itThanks

author: z80tw
author_rank: Contributor
timestamp: April 11, 2019, 05:18:28 pm
content: Just fixed my TDS420A yesterday,couldn't power on.the LVPS failed on Line voltage 110V but worked on 220V,I took out the power supply board and replaced the C10(22uf/50V).it works now.

author: vectra_1098
author_rank: Newbie
timestamp: April 11, 2019, 05:54:55 pm
content: Hi,The photo you just sent, I am pretty sure its the same PSU as mine.I do have problems though my GREEN Module is damaged and I have removed it from the PSU,I do recall that there is some schematics for them ?Somebody actually removed the green coating to reveal the circuit ?Thanks

author: ctbully
author_rank: Newbie
timestamp: April 11, 2019, 08:45:29 pm
content: You can find the service manual herehttps://elektrotanya.com

author: shakalnokturn
author_rank: Super Contributor
timestamp: April 11, 2019, 10:13:55 pm
content: Quote from: vectra_1098 on April 11, 2019, 05:54:55 pm

author: maxxim
author_rank: Contributor
timestamp: January 11, 2020, 06:15:26 pm
content: Hi, what is the value of the tantalum capacitor on the underside power supply pcb (hybrid pin 13-19).Thanks