hybridfree/eevblog-posts huggingface dataset:
Tek 400 (specifically 465) scope parts - Page 1
Forum section: electronics / repair

author: driador
author_rank: Newbie
timestamp: September 11, 2023, 04:54:32 pm
content: Greetings all, long time listener, first time caller.Quick question. I have an old Tek 465 scope here that has, like many examples out there, a broken Channel 1 vertical adjustment. The knob is gone, and the extension shaft (part number 384-1180-00) is broken off flush with the faceplate of the scope. Most of those fiberglass shafts seem to be fairly rare, oddly enough. Does anyone know if they're something special, or just plain fiberglass shafts? Just curious if I can order some .125" stock and just cut to size?Thanks in advance

author: jdragoset
author_rank: Frequent Contributor
timestamp: September 11, 2023, 05:13:24 pm
content: One left here:https://www.ebay.com/itm/364202820414

author: Gyro
author_rank: Super Contributor
timestamp: September 11, 2023, 05:42:06 pm
content: Welcome to the forum!I've never looked that closely but I'm not sure the shafts are even as good as fibre glass, more like a translucent nylon type plastic, they certainly have some flex. I've never had one break but they've aways seem rather weak. No, there's no special requirement, other than being non conductive, mainly to avoid accidental shorts against PCB components. If you can get the rod cheaply then there's little point in spending over the odds for an original, spend it on a decent condition replacement knob instead.

author: driador
author_rank: Newbie
timestamp: September 11, 2023, 07:28:20 pm
content: Thanks Chris/Gyro,I figured it wasn't anything special, but thought I would ask just to be sure. I did indeed find something equivalent at Max Gain. Two lengths of .125" fiberglass rod, each 23.25" in length for $15USD shipped. The only difference is that the rod is black and not clear/opaque white. I don't think that will matter though.Now I just need to find a replacement cap. I didn't look, but is there a swap/for-sale/trade market here at all?

author: Gyro
author_rank: Super Contributor
timestamp: September 11, 2023, 09:33:43 pm
content: You're welcome,You might want to replace the rest to match, just double check that it isn't conductive carbon fibre first.Yes, there is ahttps://www.eevblog.com/forum/buysellwanted/section here, I'm sure someone in the US will have a spare. I had a look on ebay and there seem to be a fair selection of Tek knobs available - I didn't go as far as checking the exact one. Things are a lot leaner over here.

author: WimWalther
author_rank: Regular Contributor
timestamp: September 12, 2023, 12:17:27 am
content: I believe that I have a 465 parts unit. Is OP in the USA?

author: driador
author_rank: Newbie
timestamp: September 12, 2023, 12:44:34 pm
content: Quote from: WimWalther on September 12, 2023, 12:17:27 amI am indeed! Mid-east Missouri if that helps any

author: WimWalther
author_rank: Regular Contributor
timestamp: September 14, 2023, 01:58:42 pm
content: Quote from: driador on September 12, 2023, 12:44:34 pmPM sent.
tek 453 timebase not working - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: September 19, 2019, 07:56:33 pm
content: hi all ive a 453 tek(late fet model),it was working fine last night but today the timebase knob wont work,it turns and clicks but doesent alter the time base,is the trace doesent change,any ideas where to look?,,the x10 position still works,its as if its stuck on one setting,cheers Paul m3vuv.

author: m3vuv
author_rank: Super Contributor
timestamp: September 19, 2019, 09:00:07 pm
content: sorted,it was the aluminium boss loose on the shaft!!
tek 453 trigg issue? - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: November 08, 2021, 09:47:48 am
content: Hi all,ive an old tek 453,i have just got a new probe so thought i would use the cal sig to compensate it,no mater what i do i cant seem to get the cal signal steady on the screen,its moving from left to right,it takes about one second for the left side of the trace to get to the left side,the trigger level adjust just makes it not trigger at all at the far ends of the travel either way,it slows the walking down but wont halt it,any ideas?

author: CaptDon
author_rank: Super Contributor
timestamp: November 08, 2021, 12:55:30 pm
content: It sounds like it is free running. Possible dirty sync selection switches Line, AC, DC, etc. or I think there is a trigger stability adjustment which may have the triggered sweep free running. If you get a sweep with no trigger then either your trigger selection is set wrong or there is a stability problem. There are many ways to mess up triggering on a 453 since it also has the delayed timebase feature. You probably have something set wrong.

author: med6753
author_rank: Super Contributor
timestamp: November 08, 2021, 07:11:37 pm
content: The following set up is off a Type 454 but your Type 453 should be nearly identical.Assuming your probe is on channel 1.Vertical mode - channel 1.Trigger - channel 1 only.Horizontal display - AMag - OffA Sweep Length - FullA Sweep Mode - Auto TrigCoupling - ACSource - INTAdjust the Level control to middle. It should lock. If it doesn't you do have a trigger issue.

author: m3vuv
author_rank: Super Contributor
timestamp: November 09, 2021, 03:57:28 am
content: thats exactly how its setup,deffo looks like a triggering issue!,luckily i have more working scopes!,cheers m3vuv.

author: m3vuv
author_rank: Super Contributor
timestamp: November 16, 2021, 12:16:47 am
content: well,i took the covers off of the scope and took the scope into the shower,used a small brush and some detergent and scrubbed the lot(keeping the water away from the hv section as best i could) gave all the wafer switches and front panel controls a good scrub and dousing with hot soapy water,then put it in my airing cupboard for 2 days,the upshot is that the whole lot looks like new and the trigger is working fine now on both channels,just one last thing,the fan is noisy,ive had it apart a few times in the past but the bearings are past there best!,i have a fan from a 453a,has anyone any idea if it will fit the 453 not the A version? tia.

author: m3vuv
author_rank: Super Contributor
timestamp: November 18, 2021, 09:59:22 am
content: well i thought this worked but it didnt last long,now have no trigger on either channels,any ideas anyone,when i turn the trigg level the trig light flashes for a split second but imposible to adjust it to stay on,feels like it would be ok with a 100 turn pot!
tek 453 trigger issues - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: November 17, 2021, 03:55:19 am
content: hi ive got issues with the triggering on my 453,firstly it wouldnt trigger on ch A or B,i washed the whole scope down in the shower and dried it,it now works fine on ch a but has a hard time triggering on ch b,its odd if i remove q454 and q 464 it makes no difference,the displayed waveform is very jittery but sort of triggers,the level control seems very sharp on chB but normal on ch A,any idea where i start looking? q454 was dead so replaced it but made no difference i suspect a cap ,Its a later scope with the fet front end.

author: m3vuv
author_rank: Super Contributor
timestamp: December 22, 2021, 06:30:48 pm
content: well ive replaced a resistor and a couple of caps+ a tunnel diode ,it now seems to sort of trigger on both channels but the display still moves slowly across the screen on both channels,will this be a trigger problem or sweep or even tb?,not sure where to start looking,tia.

author: med6753
author_rank: Super Contributor
timestamp: December 24, 2021, 08:12:20 am
content: If you run through the trigger calibration section of the manual it might give you a clue as to what is failing.
Tek 465 Power Supply Redo - Page 1
Forum section: electronics / repair

author: NRE_jwarren
author_rank: Newbie
timestamp: July 08, 2023, 04:15:07 pm
content: A redo on the filter caps.I'll provide feedback if anyone's interested.

author: NRE_jwarren
author_rank: Newbie
timestamp: July 08, 2023, 04:32:25 pm
content: I used both a Weller temperature controlled iron and Hakko FR-301 for the large tabs, the Hakko for the small tabs and + terminal. Caps were removed with relative ease. A Chemtronics 1/4" wide braid was used to clean up any residual that kept the tabs from loosening.Caps are Nichicon, PET, similar C-V, radials except for the 1200uF/100VDC which is a snap-in United Chemi-con.

author: med6753
author_rank: Super Contributor
timestamp: July 13, 2023, 04:38:50 pm
content: For future reference. Capacitor adapters are available on Ebay so you don't have to add wiring on the circuit board to accommodate the replacements.This is a similar 475A.
TEK 465 troubleshooting - Page 1
Forum section: electronics / repair

author: beaug
author_rank: Newbie
timestamp: January 25, 2021, 05:08:13 pm
content: Tektronix 465 (S/N B276519)I am trying to get an old Tek 465 working. I have been able to get Ch-2 working but Ch-1 will only show the trace at the very top of the display when using Beam Finder. Using the service manual, O-scope troubleshooting guide and forums I think I have isolated the problem to the Ch-1 Preamp section.I have performed the following:checked DC voltage and ripple on all rails minus 2k rail all rails DC values were good. Ripple less than 4 mVAC RMS except 110V rail was 11 mV RMS (55 mVAC p-p) and had an unusual blip (see pic below). not sure if this is normal.used the Common-mode technique on TP322 and TP324. this moved the trace to the vertical center of the display (per the troubleshooting guide this indicates that the problem is in a stage prior to the Vert. Switch. section, which also tracks with the fact that CH-2 works but CH-1 does not).used the Common-mode technique on TP141 and TP147. This had no effect.checked DC values at the following test points:TP322: +0.6135VDCTP324: -0.8034VDCTP326: +1.6321VDCTP141: +8.529VDCTP147: +7.975VDCre-seated the following transistors:Q132Q134Q322Q322I am at a loss on how to narrow it down further. Any suggestions on what to check next?SIDE NOTE: I can see the Trigger level as expected when pressing Beam Finder and Trigger View, but I noticed that the trigger level pot is inverted (turning it "-" raises the trigger level and vice versa) on both channels. Is this normal behavior? I am inexperienced with analog scopes.

author: Paul Moir
author_rank: Frequent Contributor
timestamp: January 25, 2021, 05:46:47 pm
content: Quote from: beaug on January 25, 2021, 05:08:13 pmNot really helpful but I happened to have a plugged in 465 next to me. This is normalwith DC coupling.

author: med6753
author_rank: Super Contributor
timestamp: January 27, 2021, 03:32:17 am
content: Since you have one channel working you can use it for comparison troubleshooting. Set both channel 1 and 2 to the identical setting on volts/div. Apply identical signal, such as the calibrator, to both channels. Trace the signal on both channels through the vertical circuits until you come upon a difference. That should be the area of the defect.
Tek 465B Ser# B011156 need help with Q1028 - Page 1
Forum section: electronics / repair

author: 460voltclub
author_rank: Contributor
timestamp: March 18, 2022, 04:45:41 pm
content: On the Vertical Pre Amp board I am missing Q1028. I have every service manual for the 465 except the one that shows the early schematic. I need to know what transistor I need and the orientation of the pins on the Vertical Pre Amp board.Thank You for any help.

author: andy3055
author_rank: Super Contributor
timestamp: March 18, 2022, 05:06:45 pm
content: Tek wiki page has an "early version " that might help.

author: andy3055
author_rank: Super Contributor
timestamp: March 19, 2022, 03:53:48 am
content: Sorry, I goofed up. It is the 465 not with the "B."

author: Neil Barlow
author_rank: Newbie
timestamp: March 19, 2022, 11:13:27 am
content: My early 465B manual calls Q1028 a Tek PN 151-0221. This part number can be crossed to a 2N4258 or an MPS4258 - i.e., a fairly high-speed PNP.

author: 460voltclub
author_rank: Contributor
timestamp: March 19, 2022, 03:43:42 pm
content: Thank You all for the help.

author: med6753
author_rank: Super Contributor
timestamp: March 19, 2022, 11:25:42 pm
content: Quote from: Neil Barlow on March 19, 2022, 11:13:27 amIf you can't find those an NTE159 is a direct sub.
TEK 543 Serial under 20.000 manual required - Page 1
Forum section: electronics / repair

author: ingalopez
author_rank: Contributor
timestamp: July 21, 2024, 08:50:08 pm
content: Hi there! I have adquired a Tektronics 453 osciloscope. The one with the Nuvistors. The serial number is 14.293.It was working to some extent, but after some disasembly needed to unstuck the variable A sweep pot, and clean the Position pots wich were jumping all arround, I cannot get a display.Checked the low voltage power supplies, al good. Manage to measure the -1950 V (without frying my meter!), and it is there.Also, can see the heater of the CRT glowing (fiuu...!).I got a Service manual for the 453, S/n 20.000 +, but it wont match mine.Can indicate where to get the right Service manual?And some advice to were to look will be welcome.Thanks guys

author: colorburst
author_rank: Regular Contributor
timestamp: July 21, 2024, 08:59:10 pm
content: BAMA has a copy:https://bama.edebris.com/manuals/tek/453

author: ingalopez
author_rank: Contributor
timestamp: July 21, 2024, 09:43:57 pm
content: Thank you!Will be looking into it, but it is the right one.I must have broken something with my elbow, while playing with this oldie.Also the fan was stuck, it needs replacing the bearings, but they are not easy to find in my country.
Tek 564B Timebase Problem - Page 1
Forum section: electronics / repair

author: Domokelly
author_rank: Contributor
timestamp: January 13, 2021, 10:42:01 am
content: Hi Everyone,I recently came into the company of a beautiful old Tektronix 465B.It's in great condition- cosmetically it looks great with only a few minor scuffs and dents on the exterior but otherwise it looks fantastic. it only needed a minor clean to get it to the state you see below.However it does have one problem which I was hoping someone might be able to help me out with:The type 3B4 timebase was missing a grub screw on the TIME /DEV knob (the other ring) and had come completely loose. I think it may have lost it's sync to the inner knob because unfortunately the time base isn't working at all.I managed to get it working in the 1 mSec position, but that was short lived.I've looked in the Tek 3B4 manual on Tek Wiki but can't seem to find a procedure for aligning the inner and outer time base knobs- so I think the next step will be to start checking components in the time base unit.https://w140.com/tekwiki/wiki/3B4This kind of high voltage stuff is beyond my paygrade... so I thought I'd ask if anyone had any suggestions for any easy fixes?If not I might have to take it to a professional!Thanks in advance

author: Domokelly
author_rank: Contributor
timestamp: January 13, 2021, 10:58:18 am
content: And here's the problem:
Tek 577 Step/OffSet Ampl Switch (cam switch) Strange behavior - Page 1
Forum section: electronics / repair

author: rodd
author_rank: Regular Contributor
timestamp: February 07, 2022, 11:02:58 pm
content: Hi folks,I am working on the step amplifier of this instrument and I found a very strange behavior of this switch (S404).This is one of those cam switches used in many Tek instrumentsThe voltage set part of the switch is showing a resistance much different from the one expected ( using diag 4 as reference).I removed the aluminum cover of this switch and inspected the gold fingers.All fingers are there and move as the switch is rotated.I have sprayed Deoxit gold on the contacts (fingers) and gently slided a sheet of paper when each finger was closed in an attempt to remove any dirt.Then I measured the resistance between pin 6 of U360 (signal input) and pin 3 of U380 (signal output of the resistor divider) and compared with the expected value.Note ( measurements taken with U380 pulled out)The differences vary between 30% and 1/4 of the expected value.I could not think of an explanation to such behavior.Here are the values I have measured as well as the expected values:Knob Volt reading(V) measured resistance expected value2 1.367 1.5051 2.517 3.01.5 4.317 6.02.2 7.61 15.05.1 10.18 30.1.05 12.26 60.2I am attaching the reference diagram for referenceThe measurements in question are related to the Voltage Set Resistors, on the top left part of the diagram.Any ideas?

author: m k
author_rank: Super Contributor
timestamp: February 08, 2022, 02:39:54 pm
content: So expected div 10 from .05 to .5 and 2 sets and then div 2 inside a set.Parallel 15 all the time is pretty close but no idea how it can happen.

author: rodd
author_rank: Regular Contributor
timestamp: February 15, 2022, 07:52:47 pm
content: Thank you for your reply, m.k.You figured it out!!!!There is a circuit in parallel with the voltage set resistors that I have overlooked.Please see the attached schematics.The total series resistance of this circuit is R364+R393+R391+R396 = 6.2k+2k+1K+7.5k = 16.2kRoger
Tek 577 Vertical current/div knob question - Page 1
Forum section: electronics / repair

author: adrianh
author_rank: Contributor
timestamp: June 23, 2023, 08:31:35 pm
content: Hi all. Can someone with a Tek 577 please tell me what the setting (as indicated by the knob skirt) is when the knob is turned fully counter-clockwise (ccw)? I've got a broken knob I need to reinstall. I'm pretty sure it should simply line up with the screws on the shaft, but since I had to fit the skirt/knob interface I'm lost.Thanks!

author: mawyatt
author_rank: Super Contributor
timestamp: June 23, 2023, 09:48:40 pm
content: 2A CCW on our 577 for Vert Current.Best,
Tek 577 white/green wire of Max peak Volts (S120x) switch location in schematics - Page 1
Forum section: electronics / repair

author: rodd
author_rank: Regular Contributor
timestamp: March 18, 2022, 10:12:59 pm
content: Dear all,I am trying to fix a 577 and can't complete the Vertical gain adjustment procedure.The DMM connected between pin 4 of P129 and this white/green wire of S120 reads 8v when the OFFSET MULT pot is at minimum, so I need to troubleshoot this part of the circuit.This voltage is generated in Step Amplifier (Diag 3) and it is ok @ TP360 so the problem is between TP360 and pin 4 of P129, which is located at the vertical amplifier input (dig 6).The white/green wire seems to be the ground/return wire for this signal, but it would make troubleshooting easier if I could locate this point on the schematics.Any idea of where it is?Thanks,Roger
TEK 754D repair  - Page 1
Forum section: electronics / repair

author: pmoyle
author_rank: Newbie
timestamp: July 14, 2021, 10:21:12 pm
content: My 754D started giving the ++processor fail error message on startup after the power company started power cycling every 15 minutes due to power shortage.I read that there is a NVRAM problem - maybe bad battery or out of space. Need a data restore and maybe re-cal after module replaced.Is there anyone out there that works on these things? Does anyone know anyone ? I have seen a bunch of posts from those who have already done it. Seems like someone would want to profit from the knowledge and setups/tools they already have. I can supply a new NVRAM module(s) - I have seen posts of people have a hard time finding them as they are obsolete.I don't have the time and inclination to have to get into these things. 30 yrs ago I wrote code and designed 8051 interface to read write these things, but I don't have time to bother with that either. 10 yr ago I started to take a 520 apart but it was a mechanical maze and on that one I decided the effort was not worth the result. This scope is and I hear it can be upgraded to 1 GHz, so I'd be interested in that too.It seems to work fine otherwise, but I hate that message coming up on the screen when I turn it on.
Tek 7904 Power supply help - Page 1
Forum section: electronics / repair

author: Bill Riches
author_rank: Newbie
timestamp: September 10, 2020, 10:25:24 pm
content: I have been working on my 7904 power supply for way too long! I would like to talk with someone that knows and has repaired these units. Thank you.Bill Riches, WA2DVUCape May, NJbill.riches@verizon.net

author: med6753
author_rank: Super Contributor
timestamp: September 10, 2020, 10:58:25 pm
content: I have. When I bought my 7904 it was ticking like mad. Issue turned out to be a shorted tantalum capacitor on the -17V bulk supply. What is your supply doing? Blowing fuse? Or just completely dead? Or trying to come up but going into tick mode?I have a document specific for troubleshooting the 7904 PSU but it is too large to attach here. Send me an email at seanfinn999@gmail.com and I'll send it to you.Edit...oops...just noticed you provided your email. I'll send you the document.

author: madao
author_rank: Frequent Contributor
timestamp: September 12, 2020, 05:02:03 am
content: i have repair two 7904 PSU. Both is failed with odd reason.One runs only up to 170V Input (by 230V setting), then fuse blow. One 940µF of two series is shorted.other PSU run with two simple plugin with sometime starting issues. Four plugin, it starts sometime , if PSU is warmed up. It make noise "SUMMMM ! SUUMMMM! ", not ticking !Reason: two power transistor in primary side is semi-broken (to much less current gain by higher current, less than 4 ßeta ), if transistor is hot, it hat gain of "a bit over 4" --> stable oscillation.Transistor swapped , then it run stable. I have replace him with 2N6678.Greetingsmatt
Tek 7A13 - Page 1
Forum section: electronics / repair

author: harrison@cs.unc.edu
author_rank: Contributor
timestamp: July 23, 2021, 09:17:35 pm
content: I have a broken 7A13...the later version with LED's. The serial number does not have the B for Beaverton in front of the number.Online schematics don't quite match the plug in. The serial number starts with 102xxx. Does anyone have a manual for that version?The BAMA archive is close, but not good enough to find the faulty parts.Any help is appreciated.

author: David Hess
author_rank: Super Contributor
timestamp: July 23, 2021, 09:47:57 pm
content: I would check against the documentation at tekwiki, and then ask artekmanuals.
Tek AFG3022B repair - Page 1
Forum section: electronics / repair

author: mr ed
author_rank: Regular Contributor
timestamp: December 13, 2024, 07:57:53 pm
content: I have a well used afg3022b with a channel 1 error: 2303 : offset error. The service manual is a useless modern no schematic type and the block diagram is geared for the higher end models. (That said I did get both outputs working from the dead state and number 2 is perfectly fine).Ch 1 works fine up to 40kHz where it seams to roll off down to near zero at 2MHz. The offset actually works fine but has a -50mV offset. That offset is just about at the outside of spec - but cal may be off with the roll off too.Any ideas on the roll off? Maybe someone has a better block diagram?

author: Harry_22
author_rank: Frequent Contributor
timestamp: December 13, 2024, 09:25:36 pm
content: Two identical channels. One has a problem. You couldn't think of better conditions for troubleshooting.Compare them step by step.

author: mr ed
author_rank: Regular Contributor
timestamp: December 13, 2024, 10:55:31 pm
content: I know. If it was that easy...but access is very difficult.

author: mr ed
author_rank: Regular Contributor
timestamp: December 15, 2024, 10:50:04 am
content: Fixed. Key is to get good access. Pull out power supply and tuck it under the CPU board.Issue was a hidden SMD fuse in parallel with a 0 ohm resistor between relays. Both more or less open but passing DC to 50kHz.when driving a high Z scope. Not sure why the parallel protection scheme.As a side note, it's not designed for repair but has an excellent build quality and design with Asian assembly. All Texas Instruments and Burr Brown parts etc.

author: mr ed
author_rank: Regular Contributor
timestamp: December 15, 2024, 06:57:44 pm
content: Correction: the fuse is in parallel with 10k Ohms, that explains the wierd behavior. Not that the fuse was much use, This is the carnage that was done by someone before I got it. The good side fuse measures 0.265 Ohm which may be around 3/4 Amp. Where is the bloody schematic Tektronix?
Tek CG5011 calibration - Page 1
Forum section: electronics / repair

author: syau
author_rank: Frequent Contributor
timestamp: July 03, 2020, 12:18:38 pm
content: Anybody got the calibration manual for Tek CG5011 ? The one from the web has 2 volume, Volume one has section 1 to 4 while Volume 2 start from 6 which missed the Section 5 (Calibration）

author: nicnac117
author_rank: Contributor
timestamp: April 21, 2024, 12:13:06 pm
content: Just a bump up for this question .Has anybody got or come across the Section 5 of the CG5011 manual .Its the Calibration Section .

author: calibrationfixture
author_rank: Regular Contributor
timestamp: April 22, 2024, 05:58:30 am
content: Hi,I have the Originals including Section 5. 34 Pages including a Page 5-15A and 5-15B. Till now I wasn't aware of the fact that the TekWiki Copies were incomplete.Calibrationfixture

author: nicnac117
author_rank: Contributor
timestamp: April 27, 2024, 03:24:38 pm
content: Any chance you could make it available ?

author: fmashockie
author_rank: Frequent Contributor
timestamp: April 27, 2024, 04:46:27 pm
content: I have both manual parts for the CG5011. Here's part 1. I can't attach part 2 because the file size is too large. But if you give me your email via DM I can send it to you.I also did a video series on my YT channel repairing mine which includes the following:-Fixing the current loop-Replacing the dual encoder (variable shaft broke off) with two separate encoders.-Going down a rabbit hole chasing an issue with the DC amplitude modes.Part 1:Part 2:Part 3:Part 4:Excellent piece of equipment and fairly easy to calibrate.-Frank
TEK DG2020A Schematics - Page 1
Forum section: electronics / repair

author: Ade911
author_rank: Regular Contributor
timestamp: January 31, 2023, 08:21:09 pm
content: Hi team, I have a dead DG2020A Data Generator , Ive given up with the power supply  and used separate supplies , however I now have clock errors. I don't want to brick the unit its in a good state and boots OK. Has anyone got any circuit diagrams please, I have all the manuals that are online [Also circuit diagrams for pods as it didn't come with any].Many thanks,
Tek DM44 front plate? - Page 1
Forum section: electronics / repair

author: JohnTinkers
author_rank: Contributor
timestamp: July 07, 2025, 01:45:14 am
content: Hi. Looking to buy a front faceplate for my DM44. I’ve included a photo because depending on the scope the plate can be different. If it has the DM44 card attached that is great. I’d buy that too. 🙂Checked eBay and no luck. 😞
Tek DMM150 - Page 1
Forum section: electronics / repair

author: abrasumente
author_rank: Contributor
timestamp: March 29, 2025, 01:29:27 am
content: So I recently came into possession of a Tektronix DMM 150 with a roasted display. I can safely assume two things:1) Due to the type of damage to the screen, it is donezo. Gigantic black blotch.2) This meter is almost as old as I am, so figure parts are basically nonexistentThe meter still powers up, and what part of the display wasn't brutalized still shows life. Any folks hanging around here that might point me to a hidden repository where I might procure a screen? I'd love to get this thing back to operational status and use it as a daily carry.

author: squadchannel
author_rank: Frequent Contributor
timestamp: March 29, 2025, 01:31:23 am
content: it can be repaired by replacing the polarizer. maybe

author: abrasumente
author_rank: Contributor
timestamp: March 29, 2025, 01:45:01 am
content: I don't profess to know what I'm talking about but this looks like the display equivalent of letting the magic smoke out

author: abrasumente
author_rank: Contributor
timestamp: March 29, 2025, 02:39:21 am
content: I may have lucked out. A Greenlee CM-400d appears to be the exact same meter, just rebranded. I just snagged one off fleabay for some chump change, and it came with the clamp and leads to boot!We'll see how it goes when it arrives.

author: abrasumente
author_rank: Contributor
timestamp: April 06, 2025, 10:59:00 pm
content: Success! There's some slight differences in the board layout (see photos) but the Greenlee CM-400d is essentially the same meter. Can verify all functions work as intended, including the amp clamp. The board photos show the Tektronix DMM150 board on the left, and the Greenlee CM-400d on the right.I'll probably end up listing one of the boards on fleabay. I checked both of them, the original Tektronix board reads mains a little higher than my Fluke 289, but the Greenlee board spits out basically the same (at its lower accuracy). Excuse my lack of proper calibrating equipment
Tek DPO 5104B Disk Boot Failure - Page 1
Forum section: electronics / repair

author: CrazyTiger
author_rank: Regular Contributor
timestamp: December 28, 2023, 03:43:13 am
content: Hi,I got myself a tek scope from a factory that is closing down. The instrument turn on with a Disk Boot Failure. Taking out the solid state hard disk and attaching it to my PC, the hard disk is not detected at all by my pc. So its a totally dead SSD. I am yet to see any hard disk image for this scope. Based on the windows sticker at the back, its a windows 7 ultimate emb 32/64. If i am to install a fresh installation of win 7, then install all the drivers and firmware from the tek website for the model, would it work? or is there any user with a working hardisk that can provide me their hard disk image?Thank You

author: coromonadalix
author_rank: Super Contributor
timestamp: December 28, 2023, 06:04:05 am
content: it has been upgraded to win7, not by default when purchased, normally it's win 2k if i recall or w98dont burn steps, grab everything here, theses where provided by TEKhttps://xdevs.com/docs/Tektronix/TDS5000B/please do note this is a copy of the genuine site who ask registration by Xdev's, they have the same content, be sure you have a good cd-rom in the scopeunless you have nvram battery failure or other problem, even the computer cmos battery could have died and changed some of the motherboard settings ..

author: CrazyTiger
author_rank: Regular Contributor
timestamp: December 28, 2023, 06:18:45 am
content: Quote from: coromonadalix on December 28, 2023, 06:04:05 amNot sure if this is applicable here, as TDS5104B, is an older scope. Mine is DPO 5104B, which seems like a whole generation newer.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 28, 2023, 07:13:33 am
content: could be i dont know them at all ...if someone has an hdd backup, but it could be a long or short wait ?https://xdevs.com/fix/tds5000b/#osreiand ghost file
Tek DPO40x4 repairs - Page 1
Forum section: electronics / repair

author: lokl
author_rank: Newbie
timestamp: December 11, 2020, 09:37:50 am
content: Hello,First, sorry for my bad EnglishI have a few defect DPO4034s, and a DPO4054 on my Bench which all have different problems, but all fail SPC (Signal Path Compensation). I would really like to get rid of the SPC thing, then at least one unit would be error free :-)While investigating the signal acquisition section the part "Maxim 2032859-22" caught my attention - i am unable to find any usable information about it.It looks like digikey had it of a while ago ..?https://www.digikey.com/en/products/detail/maxim-integrated/203-2859-22-TD/6615863And here the part was mentioned aswell:https://192.65.40.157/viewtopic.php?t=142260I would like to ask if anyone has some more information about it or maybe even a datasheet of that part?

author: mikehank
author_rank: Regular Contributor
timestamp: March 25, 2022, 11:25:32 pm
content: That part is the 1mohm attenuator. It’s is an ASIC so it will be hard to find a replacement.

author: TiN
author_rank: Super Contributor
timestamp: March 26, 2022, 01:56:31 am
content: I have a dead DPO4k board

author: mikehank
author_rank: Regular Contributor
timestamp: March 28, 2022, 06:06:01 pm
content: TiN,Any debug script out of the VGA connector? Pin 4 is tx and pin 11 is rx. 9600 Baud for this modle.

author: TiN
author_rank: Super Contributor
timestamp: March 28, 2022, 11:53:17 pm
content: Only have a board, nothing else.
TEK DPO4K - defective Channel 2  BNC input connector - Page 1
Forum section: electronics / repair

author: hitecelec
author_rank: Regular Contributor
timestamp: May 13, 2019, 06:54:47 am
content: Hi AllHow easy is it to replace a defective BNC Input connector on this scope. Has any one done it beforeis it possible to share the commercial part number of the BNC ConnectorThanks in advanceRegardsAnand
Tek FG501 SN 127000-128000 Cannot calibrate frequency... - Page 1
Forum section: electronics / repair

author: JohnTinkers
author_rank: Contributor
timestamp: July 11, 2025, 10:54:05 pm
content: Hi. I've got a Tek FG501. Serial number is between 127000 and 128000.It was old and jumpy and out of cal. Began to calibrate per the manual.Got through the steps to verify volts +13.8, +20, +17 and -17.Got through calibrating the square wave.Did the Dial calibration and that is, as Dave would say, very "How ya' doin." I got it set properly or so I thought.Square wave symmetry, bang-on.X10 cal, got it spot on to the single hertz!Then the excrement hit the fan at X1 cal. With the count showing 25% high, I ran out of adjustment in the trim pot -- and these things are horribly touchy. I've been tempted to rip them all out and put in some nice 10-turn Bourns trimmers.If I try to slack off on the 10X cal, I still can't get the X1 cal in place or even within 15-20%I tried hitting the trim pots with Deoxit F5, working them, and letting them dry out overnight. No joy. Almost the same result. I have also hit the pot for the dial with deoxit F5 in a dropper. Got rid of the jumpiness but the cal is still off.The circuit is a typical Tektronix 1970s cryptic. nightmare.So I felt around and there is a very hot Tantalum cap. Doesn't test short, however. I include it in the schematic below because it is somewhat close electrically to the cal pots in question.The electrolytics in the power end of the thing are date coded 1974! I'm ordering replacement caps from Mouser.Am I worrying about the wrong thing here?Thanks!John.

author: BreakingOhmsLaw
author_rank: Frequent Contributor
timestamp: July 14, 2025, 09:01:25 pm
content: If a cap gets hot, it's leaking. Replace it.

author: Kwakerman
author_rank: Regular Contributor
timestamp: July 14, 2025, 10:06:42 pm
content: If you have an infra-red camera take a look at it with that. They are good at spotting warm tants before they go properly short. Just replace any that are showing as warm as they will all be at the same age.

author: JohnTinkers
author_rank: Contributor
timestamp: July 15, 2025, 04:19:33 pm
content: Hi - I just got replacements in and will be replacing all tants on the PCB. My Flir DM166 deploys, and sure as can be, they're hot. I just got in new Electrolytics for the smoothing caps in the power supply too. So every electrolytic on the board will be new.Hopefully that gets me to stability, but I am worried about some of the op amps and possibly the CC resistors on the board. None of them look cooked, but caps standing alone don't seem to explain those symptoms.Thanks!!!
Tek FG504 no workee - Page 1
Forum section: electronics / repair

author: audionautica
author_rank: Newbie
timestamp: May 21, 2023, 05:38:58 am
content: My FG504 is sick.When I turn the mainframe on, the signal is there for about a second and then disappears.Failure then manifests itself in one of two ways :EITHER - no volts at all on power rail test pointsOR - +25 and +15 is present, -25 and -15 is not present.DCR check on the rails does not indicate short to ground, and have checked the obvious tants that I can see for shorts. Can't find any.Very odd that there is a signal for a second or so on power up and then it disappears.Any ideas where I should start?PS - No, I don't have extenders, however I can slide the side off my TM5006 which allows me to access quite a lot in situ.

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: May 21, 2023, 07:39:04 am
content: Hi audionautica,is the problem on all six slots?Maybe one of the external transistor for the psu-reg went bad.Check the slot-contacst also.Are all electrolytics good??Good luck
Tek MDO 3012 intermittent failure - Page 1
Forum section: electronics / repair

author: hitecelec
author_rank: Regular Contributor
timestamp: October 21, 2019, 05:20:59 am
content: hi Allunit had an intermittent problem. used to Boot up, pass all power on self tests successfully and shot down within 5 minutes.diagnosis- defective TOP221YN in the SMPS. Probably thermal shut down.Unit working ok.Hope it is usefulregardsAnand
(fixed) Tek P6201 active probe - Page 1
Forum section: electronics / repair

author: richnormand
author_rank: Unknown
timestamp: March 10, 2023, 05:47:29 pm
content: As seen in the photos one of the coupling pin is broken.The probe itself works well but it is inconvenient when switching attenuator to remove the coupling pin.Does someone know of the availability of these before I bite the bullet and attempt to repair/machine it?Cheers and thanks.

author: alm
author_rank: Super Contributor
timestamp: March 10, 2023, 10:53:10 pm
content: I'm going to guess that the only availability of this is other used attenuators, and maybe the spare parts dealers likeQservice (Greece)orSphere (Canada). It might help to find the part number in the manual and search for that on these stores or eBay.

author: james_s
author_rank: Super Contributor
timestamp: March 10, 2023, 11:08:52 pm
content: Can you remove it or is it molded into the plastic? Maybe you could use a precision mini lathe to drill the location of the original pin and press in a new one?

author: Jeff eelcr
author_rank: Frequent Contributor
timestamp: March 11, 2023, 12:45:00 am
content: Part number is 206-0200-00 for tip.Jeff

author: richnormand
author_rank: Unknown
timestamp: March 11, 2023, 03:50:36 pm
content: Thanks Jeff, James and alm.I'll look up Sphere. I finally found the manual on-line for the probe.The plan B is using a cut to length needle and spot weld it to the screw base.With the proper part number from Jeff I located a few sources. Looks like they are pretty expensive.Cheers.Edit: just prepping up the surface and the base is brass it looks like. Spot welding wont work.I'll use a fine drill bit and a needle to solder it in place in the hole....

author: richnormand
author_rank: Unknown
timestamp: March 13, 2023, 08:26:03 pm
content: While locating a source for these pins I got a temp fix that might be adequate for a while.As seen in the photos of the original posting the outside pin is 0.1570" long and 0.0300" in diameter.I usually work in metric but since this is an original Tek part I figured it would match drill sizes better.To replace the probe pin I used one of the numerous clothing pins I got when I got a new shirt. You can see its remains in one photo.The shirt needle is 0.0255" in diameter, a good fit for a 0.026" drill using the Dremel in a makeshift drill press.Located the center of the brass pad with the screw thread and used a jeweler's file to make two V grooves at 90° to position the drill in the middle and prevent wandering.After prepping the surfaces and the pin it was hard soldered in the hole and cut/sharpened to size. It screwed back in its original position without fuss after cleaning the leftover flux.Probe works perfectly with the witch hat and the IC accessories.Hope this might be useful to someone in a similar situation.

author: james_s
author_rank: Super Contributor
timestamp: March 13, 2023, 09:26:42 pm
content: Looks like that ought to do the trick.
Tek P6248 cable repair - Page 1
Forum section: electronics / repair

author: SBW
author_rank: Newbie
timestamp: August 27, 2018, 05:16:36 am
content: I have a Tek P6248 differential probe that seems to have had its cable yanked. Three of the wires have broken off their pins at the connector on the back of the probe. My problem is that I do not know which goes where. Looking at the back of the connector (solder cup side, not mating side) I have:Coax signal Coax shieldPurple Black? Red? ?The broken wires are brown, white, and blue.The 'red' wire is more orange than red, but there is also a loose orange wire that I suspect is a NC.Given the lack of strain relief on the cable, and the fact that the P6248 I borrowed from a friend also seems to have similar damage, it seems likely that this is a common problem. But not so common that I was able to find the pinout, or enough schematic information to deduce the pinout.Can anyone tell me which wire goes where?Thank you,Steve

author: tautech
author_rank: Super Contributor
timestamp: August 27, 2018, 05:25:58 am
content: Welcome to the forum.This may or may not help:Tek Probe Circuits ~19Mbhttp://w140.com/tekwiki/images/6/62/062-1146-00.pdfP91-It's old but could point you in the right direction.

author: Haitarai
author_rank: Newbie
timestamp: August 27, 2018, 07:01:20 am
content: I'm looking for this information to fit it.

author: KrudyZ
author_rank: Frequent Contributor
timestamp: August 27, 2018, 11:23:32 am
content: Here you go!I hope that's the side you're interested in. I don't really feel like unsoldering the shielded case of the probe itself to peek inside...

author: Milhouse
author_rank: Newbie
timestamp: February 22, 2025, 07:24:55 am
content: Hello,I'm a little late in this thread, but maybe someone has an answer or Steve was able to solve the problem.It's about the pinout of the microwires of the P6248 probe. The wires are disconnected and I can't clearly identify the pinout.Any help is welcome.Best regards,Eric
Tek Power Supply Capacitor Q... - Page 1
Forum section: electronics / repair

author: icy.dev
author_rank: Contributor
timestamp: August 13, 2019, 12:40:27 am
content: Hey Folks!First post and I'm just a tinkerer....So I'm replacing the PS Caps on my Tek 475A....I cannot find the same capacitance ratings for replacements.I've read Ron Childress' Tek 465 PDF and it was VERY helpful but as a noob I question the selection of replacement capacitor ratings....Part Purpose Original ReplacementC1512 +110 VDC Filter Cap 550 uFd, 100V 560 uFd, 160VC1513 +55 VDC Filter Cap 1200 uFd, 100V 1200 uFd, 160VC1542 +15 VDC Filter Cap 5500 uFd, 30V 5600 uFd, 35VC1552 +5 VDC Filter Cap 5000 uFd, 25V 5600 uFd, 35VC1562 -8 VDC Filter Cap 3000 uFd, 35V 5600 uFd, 35VI don't question Ron of course...esp because his scope works now....But I just cant get around choosing a 5600uFd cap in place of a 3000uFd one (C1562)I have more than these caps to replace and I really need to understand the logic behind it!!!!PLEASE educate me!dc

author: jdragoset
author_rank: Frequent Contributor
timestamp: August 13, 2019, 01:13:34 am
content: In general, PS caps can be replaced with a larger capacitance value and voltage rating, provided the package fits in the location.This will work within at least a 100% increase of capacitance and likely not cause a fuse or diode overload.This philosophy also works for in-circuit decoupling across resistor networks, etc.Looking at the tolerance spec', e.g. "+50,-10% or +100%" is also a good indication that substitutions can be increased in capacitance value without ill effect.This helps with limiting the number of values that must be purchased for such replacements.
Tek Probe tip (P6046) repair suggestions - Page 1
Forum section: electronics / repair

author: aarons
author_rank: Regular Contributor
timestamp: May 29, 2025, 07:02:05 pm
content: I got a differential probe at auction, but failed to notice in the pictures that one of the probe tips is broken off (and the other is bent, so perhaps soon both will be broken off). Ideally I'd be able to buy the little part with the tips and switch that lives inside the probe housing, which is easily removable with a few screws, but I'm guessing that isn't going to be easy to find. It looks like if I had like a jewelers drill press I could drill out the broken pin, and replace it with something new, but I don't have the tools available for that.Anyone have any suggestions?

author: srb1954
author_rank: Super Contributor
timestamp: May 30, 2025, 01:51:21 am
content: Download the product manual and carefully follow the instructions for dismantling the probe. Damage could result to delicate and irreplaceable components inside by failure to follow the procedure. Also, carefully follow the instructions for reassembly as the performance of the probe could be affected by incorrect placement of cabling etc and require that a recalibration be carried out to restore performance.There doesn't appear to be a procedure given in the manual for replacement of individual probe tips so they may have to be replaced as a pair.

author: richnormand
author_rank: Unknown
timestamp: May 30, 2025, 05:28:49 pm
content: Had a similar situation with a Tek probe.See:https://www.eevblog.com/forum/repair/tek-p6201-active-probe/msg4753490/#msg4753490Hope this might give you some idea on how to approach a repair.Still working just fine.
Tek PS2521G RAM dump - Page 1
Forum section: electronics / repair

author: DadBurnit
author_rank: Newbie
timestamp: May 02, 2020, 08:06:59 pm
content: Hello all. First post to EEVblog. Been lurking for years. I have a Tek PS2521G needing repair. Does anyone have a copy of their NVRAM they could share or know where I might find a copy. I am looking to compare my NVRAM.
TEK scope 2465B power supply  - Page 1
Forum section: electronics / repair

author: jonpaul
author_rank: Super Contributor
timestamp: November 12, 2020, 09:39:45 am
content: Bonjour a tous:Have a blown 2465B PSU, a late SN with many nice options.PSU a line startup/transistor driver issue.In debugging, I may have blown the main switch transistors and driver parts. I am about out of time.I asked Walter at Sphere, if he had any spare PSU and came up empty.Qservice in Greece has them but cost + shipping is a large fraction of the value of the scope!If anyone has a junker/parts 2465/A/B (all same PSU, I think) that can yield a good PSU, OR a spare that works, I am very grateful.If in USA, can ship on my Fed Ex acct, to USA location. Or if you are in EU, post to an adresse in Paris.Am open to any reasonable swap, have TEK probes, spare TM500 and 7000 plugins and spare parts.Mille Mercis pour votre gentil aide!Bon Journee,Jon