Date   

Re: Tek 555 service manual.

John Clark
 

There appear to be a few on eBay. Most are listed as service manuals even though they say "instruction manual" on the front. However, looking at listing pictures item 271658505408 looks like the same version that's available on the Tek wiki site that has full diagrams, parts lists, and theory of operation. $26 and free shipping seems reasonable.

John
To: TekScopes@yahoogroups.com
From: TekScopes@yahoogroups.com
Date: Fri, 22 Jan 2016 08:25:33 -0800
Subject: [TekScopes] Tek 555 service manual.


























Was wondering if anyone here had a factory service manual for a 555 scope. I have the instruction manual already. Thanks for any time and help.








Garrett










[Non-text portions of this message have been removed]


Re: Tek 555 service manual.

Artek Manuals <manuals@...>
 

Garrett

IF the manual you have has a part number on the title page in the lower
left hand corner which is 070-165
Then that is the factory Service manual ( actually it is a combined
Operator & service manual ) IF your INSTRUCTION copy has the part number
above on it but has no schematics then your copy is incomplete ...

WE have a COMPLETE copy of that manual for download but I think it is
likely there are free copies available on the WEB


Dave
ArtekManuals.com




On 1/22/2016 11:25 AM, lbfulton@windstream.net [TekScopes] wrote:

Was wondering if anyone here had a factory service manual for a 555
scope. I have the instruction manual already. Thanks for any time and
help.


Garrett



[Non-text portions of this message have been removed]

Garre

--
Dave
Manuals@ArtekManuals.com
www.ArtekManuals.com


Tek 555 service manual.

zerousair
 

Was wondering if anyone here had a factory service manual for a 555 scope. I have the instruction manual already. Thanks for any time and help.


Garrett


Re: TDS754A printer compatibiliy

Vince Vielhaber
 

I don't know if this helps at all, but the 2040 is a PCL-5e printer.

Vince.

On Thu, January 21, 2016 11:14 pm, edbreya@yahoo.com [TekScopes] wrote:
Thanks Al,


I tried the laserjet and almost every other one too, but it didn't work
with the Brother HL-2040. I'm wondering if maybe the printer's
communication and format settings can be changed via a PC hooked up to
it. I don't recall ever seeing any explicit provision for that in
printers, since the drivers usually take care of all the details.


Ed





--
Michigan VHF Corp. http://www.nobucks.net/ http://www.CDupe.com/
http://www.foggymist.com The Foggy Mist Emporium


Re: TDS544A status

Siggi
 

My TDS784D does this as well. I recapped the CRT driver board, which
alleviated this for a spell. I was in email contact with another TDS owner
who found that in his case it was due to degradation of the connections to
the horizontal deflection coil. Apparently there's reasonable peak currents
there and the connector is not so hot.
Once I get through the pile of HP gear hogging my bench ATM, I'll give the
connections a look-see and a good clean, as this random, flickering
shearing is a little annoying.

On Thu, Jan 21, 2016 at 23:04 edbreya@yahoo.com [TekScopes] <
TekScopes@yahoogroups.com> wrote:



Now I'm getting paranoid - I just remembered that lately the 754A display
sometimes has slight flickering in the display shortly after power-up, and
then would be OK after warming up a bit. I hope this is not a sign of
impending doom like a flaw in the HV transformer that gets worse as
happened in the 544A. I'm thinking about maybe opening it up to see if
there's any evidence of HV leakage on the outside of the transformer.



Ed






Re: TDS544A status

 

Hi Ed,

I have a number of those HV assemblies lying around from doing conversions to LCDs
They were converted as the CRTs were too dim for resale. I've been slowly unloading them on Ebay, but they're not hot sellers by any means. You can see one of them in Ebay item 321799417496
http://www.ebay.com/itm/Tektronix-TDS784C-HV-CRT-board-for-TDS700-600-and-500-series-oscilloscopes-/321799417496?ssPageName=STRK:MESE:IT http://www.ebay.com/itm/Tektronix-TDS784C-HV-CRT-board-for-TDS700-600-and-500-series-oscilloscopes-/321799417496?ssPageName=STRK:MESE:IT
If you're in the US, I'll send one to you for $75 including shipping.

Jay


Re: TDS544A status

stefan_trethan
 

It can never hurt to open it up and have a look.
Except in those cases where you damage something in the process of course. ;-)

Even if there is nothing to be found at the very least it will give
you some idea what to expect when things do go wrong.

ST


On Fri, Jan 22, 2016 at 5:04 AM, edbreya@yahoo.com [TekScopes]
<TekScopes@yahoogroups.com> wrote:
Now I'm getting paranoid - I just remembered that lately the 754A display sometimes has slight flickering in the display shortly after power-up, and then would be OK after warming up a bit. I hope this is not a sign of impending doom like a flaw in the HV transformer that gets worse as happened in the 544A. I'm thinking about maybe opening it up to see if there's any evidence of HV leakage on the outside of the transformer.


Ed



[Non-text portions of this message have been removed]



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Posted by: edbreya@yahoo.com
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Yahoo Groups Links



Re: TDS754A printer compatibiliy

Tothwolf
 

On Thu, 21 Jan 2016, edbreya@yahoo.com [TekScopes] wrote:

I tried the laserjet and almost every other one too, but it didn't work with the Brother HL-2040. I'm wondering if maybe the printer's communication and format settings can be changed via a PC hooked up to it. I don't recall ever seeing any explicit provision for that in printers, since the drivers usually take care of all the details.
According to the user manual, it looks like the HL-2040 only supports GDI. The 2070N supports PCL, Epson FX-850 and IBM Proprinter XL emulation. See pages 2-1, 2-17, A-2 and A-3

https://www.brother-usa.com/ModelDocuments/Consumer/Users%20Manual/UM_HL_2040_2070N_EN_1289.PDF


Re: TDS754A printer compatibiliy

Tothwolf
 

On Thu, 21 Jan 2016, edbreya@yahoo.com [TekScopes] wrote:

I tried the laserjet and almost every other one too, but it didn't work with the Brother HL-2040. I'm wondering if maybe the printer's communication and format settings can be changed via a PC hooked up to it. I don't recall ever seeing any explicit provision for that in printers, since the drivers usually take care of all the details.
I'm not sure if this will help, but I have a HL-2070N which is the same basic printer as the HL-2040 but it also has a network interface. The default mode for the 2070N is the Epson FX-850 but it can be switched to the IBM Proprinter XL via its built-in webserver based configuration page.

If you happen to need it sometime, I have the service manual for these printers in pdf format. I don't remember where I got it from but Brother doesn't seem to make it publicly available.

Also, if you ever begin to have trouble with the printer not feeding paper, pick up a LM6291001 paper feeding kit (mine was ~$15 from a printer supply company). The feed roller assembly in these printers seems to last for about 20k-25k pages after which the textured roller surface is worn too much to reliably pull paper from the paper tray. Installing the roller requires quite a bit of disassembly (and you have to carefully align the marks on the gears while installing it), but following the diagrams in the service manual makes it pretty easy.

If you have trouble with double-feeds, there is a small rubber dampening pad for the feed solenoid that breaks down and turns into a sticky tar-like goo. Removing it solves the problem, although after removing it, you can definitely hear an audible click when the solenoid pulls in.


Re: TDS754A printer compatibiliy

Ed Breya
 

Thanks Al,


I tried the laserjet and almost every other one too, but it didn't work with the Brother HL-2040. I'm wondering if maybe the printer's communication and format settings can be changed via a PC hooked up to it. I don't recall ever seeing any explicit provision for that in printers, since the drivers usually take care of all the details.


Ed


Re: TDS544A status

Ed Breya
 

Now I'm getting paranoid - I just remembered that lately the 754A display sometimes has slight flickering in the display shortly after power-up, and then would be OK after warming up a bit. I hope this is not a sign of impending doom like a flaw in the HV transformer that gets worse as happened in the 544A. I'm thinking about maybe opening it up to see if there's any evidence of HV leakage on the outside of the transformer.


Ed


Re: TDS754A printer compatibiliy

allanjamison
 

Ed:

I have a TDS 544A and it has a centronics parallel port. I have used it with several printers that use the standard HP PCL language. Set the printer options to output to the centronics port and select the laserjet format.

It should work. The PCL format uses ASCII characters and it a very common standard in the older, more expensive printers, from many vendors. Many current printers also support PCL but you have to check the specifications. Very inexpensive printers now do most of the formatting in the PC and require proprietary drivers.

I hope this information helps. I am assuming the your TDS 754A has similar options.

In my TDS 544A there is also a floppy disk that you can use to save standard image formats. These formats can be processed by most PC drawing and word processing programs. That is another way to get a screen print into a document or print it out.

Al Jamison


Re: 7603 Strange HV Need Help

Ed Breya
 

Yes, the sockets can cause much more grief in terms of diagnosis and repair. I was thinking more in terms of frequency of occurrence - I've seen way more stories about bad caps, although perhaps sockets actually are the cause of more trouble than is attributed to them.


Ed


Re: 7603 Strange HV Need Help

 

I would actually rank the TI sockets as a larger problem than tantalum
capacitors. The capacitors unambiguously fail and are relatively easy
to find and replace. The sockets become intermittent with no visible
sign and replacing them is a much more involved procedure.

On 21 Jan 2016 14:21:24 -0800, you wrote:

The problems with TI sockets and ICs with silver plated leads are well known, and have been discussed here a number of times over the years. Unfortunately, Tek used a helluva lot of them in many of our favorite instruments from that era. I believe they are one of the main causes of problems - especially strange and intermittent ones. I'd rank the TI problem well below the usual bad Ta caps and worn out Al caps, but it's up there somewhere near the top of the list.

Ed


Re: 7603 Strange HV Need Help

 

I have never encountered this problem with silver or these TI ICs of
which I have lots but I have with thick gold. I assume the leads are
FeNi42 which was a common lead frame material in the past and whatever
process which is needed to plate silver to FeNi42 was lacking.

Maybe silver sulphide which is that black tarnish you find on silver
can form between the lead frame material and the silver isolating it.

On 21 Jan 2016 15:42:36 -0800, you wrote:

In a nutshell, there is something seriously galvanically and/or metallurgically wrong with those TI IC leads with Ag plating. Over time, and depending on the environment, the bond between the Ag plating and whatever is underneath disintegrates, literally disconnecting the outside surface from the leadframe material, causing loss of contact. I have even seen this in leads that were soldered to the board clean through.

Ed


Re: 7603 Strange HV Need Help

Ed Breya
 

In a nutshell, there is something seriously galvanically and/or metallurgically wrong with those TI IC leads with Ag plating. Over time, and depending on the environment, the bond between the Ag plating and whatever is underneath disintegrates, literally disconnecting the outside surface from the leadframe material, causing loss of contact. I have even seen this in leads that were soldered to the board clean through.


Ed


Re: TDS544A status

Ed Breya
 

OK - message sent.


7834 Transformer rewind

Gordon <tekscopes@...>
 

Hi all. The 7834 transformer has been running for a couple of days now and appears to be OK. I just thought I'd post some details. The first attempt blew through the windings. One of the issues with layer winding as opposed to bank winding is the way Tek anchored the HV winding tails. They use a small circuit board to fix the fine ends and the Teflon output wires. The problem with layer winding and the circuit board is that the start has to come up and over the return of the second layer which is at about 1400V. You can insulate it but the potential for a flash over is higher. It doesn't happen with bank winding as the high voltage end is always at the opposite end to the low voltage.

The second attempt didn't blow but the voltage was too high, it wouldn't regulate. There really could only be two reasons why output > input * turns ratio. I'd got the turns wrong or it was resonating. I was a little skeptical about the distributed capacitance causing resonance. Whilst I could see it would be critical in a tank circuit, why would it make that much difference in what is really just a transformer? I'd fairly good reason for the line of thinking. The reason I have a coil winder is from my guitar pickup winding days. I know from past experience and data that a guitar pickup capacitance is in the order of 100pf. They vary a lot but 100pf is not untypical. This is for a coil of circa 8000 turns single insulated 0.063mm polyurethane. Just how much capacitance could a 610 turn coil have? Prepare to be amazed, at least I was.

Thinking I must have got the turns wrong I wound a third coil. No change so it had to be distributed capacitance. The thing self resonated at 25k - how convenient! It's the working frequency of the switcher.

To get a grip on how the coil could be wound to reduce the capacitance I did a series of simple winds.

455 turns 0.08mm (~40AWG) in two 25mm layers on 19.6mm piece of wood dowel. In the following when I say insulation I'm talking about insulation between the layers. There were odd bits of Kapton to hold things in place. 'Return wound' is where at the end of a layer the wire is brought back over the wind so that the layer starts are always at the same end. I'm not sure of the proper name for it.

I used the two capacitor method for measuring, there's an on line calculator here http://www.vk2zay.net/calc/DistributedCapacitance. There are others but they give the same result.

Single build solderable polyurethane, no insulation = 953pf

Single build polyester, no insulation = 634pf

Single build polyester return wound, no insulation = 335pf

Single build polyester 1 layer 5 mil Formex insulation = 78pf

Single build polyester 1 layer 10 mil Formex insulation = 33pf

Just as a sanity check I checked an old guitar pickup I had lying around, IIRC 7650 turns single build 0.063mm polyurethane - 76pf - go figure?? As a double sanity check I redid the first test and got the same result.

Given the massive difference the insulation makes I used solderable Polyurethane for the final 610T HV wind. I'm not keen on scraping these fine wires. All others were single build Polyester.

I managed to get some Micanite but it might actually be better using Formex, being polypropylene it has a lower dielectric constant than Micanite. The downside is that it won't stand much heat - working temperature of 115°C. Lets hope it's enough. The good thing about flexible Micanite is that it stays formed. Once you've wrapped it round it more or less stays there. The 0.01" Formex is quite springy, it needs holding down quite well with tape.

I dispensed with the little circuit board Tek used and fixed HV Teflon wire to the coil ends. This brings it's own problems, anchoring them sufficiently to prevent them being yanked out. I soldered the ends to a small (about 5*5mm) square of copper tape and used that as the anchor on top of some Kapton. The copper tape sticks like the proverbial so it should be OK. Small bits of Tape don't stick that well to Micanite. If you tape over Micanite make sure it goes all the way round so the tape sticks to itself.

There are some shoulders of insulation on the original. Presumably to support the bank wind. I put them on but wouldn't if I was doing it again. Ideally the between layer insulation needs to be wider than the coil. If there are shoulders there you can't really do that with 10 mil insulation. Another problem with using thicker insulation is that you can't slit the edge and slip it over the start of the return wind. It would probably weaken the wire, that's if you could manage to do it. I got round it by leaving a gap of about 1.5mm in the insulation over the width of the coil with a piece of Kapton under the gap.

I also finished the second layer of the HV winding 4mm short of the end. I've uploaded a drawing here http://www.mgcsoft.com/tek/7834_hv_transformer_drawing.pdf. I didn't stick exactly to the original drawing mainly because tape is much easier to get here (UK) in metric widths. Some of the insulation lengths on the drawing may not be exactly right after the bifilar winding. I'm not about to rewind it just to check the lengths!

I found it easier to take the taps out to the right hand side then bring them back to the left once the wind was finished. If you take them to the left/insulate then wind on top, it's harder to get the continuing turn to lay properly. I'm guessing it's how seasoned winders do it anyway.

On the drawing it specifies to "Fold back wires 1,4, 5 and 6, I didn't. It's probably for strength and easy enough if you're using a hot chemical stripper. If you're scraping you have to separate the wires, then you don't know which is 'live'. It's not a problem with single wires if you're careful.

When you come to fit the transformer the wires are conveniently 1:8 left to right as you look at the back of the board with the transformer on top.

It's quite easy to check the HV wind without finishing the transformer. Do the bifilar wind which is relatively easy. Put the coil onto the core and drive the bifilar wind with a 50Ohm sig gen at 25kHz. No need to run it at full voltage, 1V will do. I don't know whether it's necessary but I tacked a 3.3M resistor load onto the 610T wind. If Vout > Vin*turns ratio you have a problem which is likely to get worse when the other winds are done.

A small point but the original drawing for the transformer is wrong. It's been corrected, sort of in the change log. The change log extends wire (4) to 1"3/8 because it was too short. What should have been done is to reverse the lengths 1:4 they should be 1=1", 2=1"1/8, 3=1"1/4, 4=1"3/8. They're the other way round on the drawing.

Sorry about the mixed units. My brain works pretty much the same way - mixed :-)

Cheers

Gordon


Re: TDS544A status

stefan_trethan
 

Charly is c.dickens@xs4all.nl
or if yahoo tries to mess with it again:

c.dickens at xs4all.nl

ST

On Thu, Jan 21, 2016 at 11:34 PM, edbreya@yahoo.com [TekScopes]
<TekScopes@yahoogroups.com> wrote:
I'm not sure what you mean:


"hi Ed please send me an email I have the same unit TDS544A and calibration software. now I can buy a TDS754D processor fail. send me email please: c.dickens@... mailto:c.dickens@...


please email me.
greetz charly "



I can't send emails directly to anyone in the group because the address is blanked. I think you can email to me at my user name at yahoo.com.


Ed








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Posted by: edbreya@yahoo.com
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Yahoo Groups Links



Re: TDS544A status

Ed Breya
 

I'm not sure what you mean:


"hi Ed please send me an email I have the same unit TDS544A and calibration software. now I can buy a TDS754D processor fail. send me email please: c.dickens@... mailto:c.dickens@...


please email me.
greetz charly "



I can't send emails directly to anyone in the group because the address is blanked. I think you can email to me at my user name at yahoo.com.


Ed

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