how do you remove a stuck tektronix 5-series TM504 plugin?

[linux-works]

I bought a tm504 tektronix chassis from ebay and one of the modules has a broken off puller, at the bottom of the module.  I'm hoping there's a way to get it out of the chassis somehow?

I'm brand new to this chassis series, this is the first I've touched one.  does that pull tab thing also function as a power-on switch for the module?  the one module that is still stuck in the chassis does not seem to fully power on; one light comes on but I don't see an led 7seg display showing any life signs.  so I'm not sure if that pull tab is just a mechanical thing or if it also has electrical use as well.

[MarkL]

I've never seen a module where the latch controls anything.  You're supposed to always turn the power off before inserting or removing a module.

I would take the bottom cover off the chassis and try to disengage the latch with a small screwdriver.  I have a TM503 and it looks doable.

[linux-works]

ok, I just confirmed the module does at least basically work and the latch does not do anything other than a mech lock.

I was advised to remove the bottom plate so I'll try that and see if I can get the latch to move.

[calin]

If is broken close to surface just use a needle nose pliers and pull the tab out. I do that all the time with my TM503.  I have a DC504 and FG540 in it and the counter latch is broken. The latch does not have any electric connection. If you can't catch it take case of the module out and disengage it that way . Don't break the latch so it does not engages anymore because after that the module may slide out if you move the whole rack around - you will be left only with the power connector backplane holding the module in place in that case.

[alex.forencich]

I havea module that is missing part of the latch as well.  The only way I found to get it out of the rack was to remove the bottom panel and unscrew the guide rail.  Then the guide rail and module can be removed and separated, and the guide rail reinstalled.  I ended up removing the rest of the latch assembly until I can get a replcement, because it's impossible to remove the unit from the mainframe without taking the mainframe apart. 

If a module is partially powering on, there may be an issue with either the module's internal regulators or possibly the mainframe's supplies.  The TM50x units actually provide a pair of transistors that the module can use as positive and negative pass transistors for two supply rails.  There could be an issue in this circuitry somewhere that is preventing the module from working correctly.  I also got a TM503 with a bad filter cap in the 5v supply.  An AM503 worked perfectly, but a frequency counter did not as the AM503 did not use that supply rail. 

[linux-works]

get a load of this!



this is an sg503 sine gen plugin.  only the top range was working when it arrived in the mail, yesterday.

what do they say here?  open it up!

I wish I did that first.  that nomad transistor could have done some real damage!  luckly it just HUNG OUT THERE on a cable, not helping but not hurting, either.

I could see where it had come from so I guessed, plugged it into its triangle just above where it was resting, plugged the module in and now things work fine.

the bug on this module was that only the top freq range would work.  no other range would output any sines.  it seems there is a different osc used for the top range vs all the rest.  the 'all the rest' must have gone thru that nomad xistor

wow.  this is a good argument against socketing things.  especially things that have heat sinks on them!  come on tek.  this was not a good thoughtful design here, you have to admit it.  if a unit can bounce out during shipping, that's not a good design in my book.

at any rate, it now works.

[ahnuts72]

Hopefully you don't have any more trouble out of it.

I wouldn't get rid of my tm506 series mainframe for anything.
Even if I replaced everything in it with modern equipment.
The only thing I have done is replace the ps-501 with another
ps-503a and tied the outputs of the positive supplies to the dm-501a
internal connections.
Haven't had one lick of trouble from it.
Here's a pic of me testing everything after I received it.

[PaulAm]

Tektronix eventually dropped the sockets.

It's kind of a mixed bag.  Sockets make repair and testing very easy, but it's also a major reliability issue.  I've fixed several instruments just by removing and reinserting the transistors.  It has also facilitated tracking down marginal semiconductors since I can just pull them and plug them into my curve tracer.

The pin sockets aren't too bad.  In the 7000 series they used sockets that had wipers on the sides of the pins. made by TI.  Those are a major reliability headache and an engineer's nightmare.  With those sockets, removing and reinserting the IC can actually make the situation worse.  The only thing to do with them is to replace them with quality sockets (or solder the ICs in directly, but I prefer to not do that on boards of that vintage).

[linux-works]

I'm brand new to the TM5 series plugins, but I'm getting interested in this architecture.  even though its old, I like how little space the plugins take and they don't have to be permanently on your bench; only the chassis has to sit there.

what are some of the favorite and useful plugins people have for the TM5?  anything I should try to add to my collection?  I know that's quite an open question but I'm curious what people like and also (more important) which troublesome modules to avoid like the plague.

I was told to avoid the 4 digit modules and stick with the 3 digit ones.  anyone have any comments about that statement?  I was looking at this module (ps5010) but was told it was impossible to repair later on, or something to that effect.

[BravoV]

Talking about socketed semiconductor, I think in 60s when Tek was moving from vacuum tube technology, at their earlier design almost all semiconductors are socketed. 

Anyone know why ? Expensive semiconductor price at that period maybe ? Or for the ease of repair ? 

Few examples from my Tek 2901 time mark generator teardown, even at the 2N3904 transistor 

[linux-works]

I see some chips in my plugins are socketed and some are not.

early chips and mosfets were very easily static damaged, so I could see the speed in having sockets for repair.  but they add all kinds of nasty inductance and capacitance and seem quite counter to high speed design.  yes, I'm sure they avoided sockets for anything speed-critical.

I should shoot some more pics of the plugins I got.  there are a lot of 'bodges' there; components hacked in, standing on their own legs air-wired, stuff paralleled on top of each other, etc.  some plugins are pretty messy looking, to be honest.  I wonder how many tek engineers were working on the modules, at their peak of popularity?  I would also guess that the design skill level was quite varied since some modules seem a bit cleaner inside (layout, etc) than others.

[ahnuts72]

I was told to avoid the 4 digit modules and stick with the 3 digit ones.  anyone have any comments about that statement?  I was looking at this module (ps5010) but was told it was impossible to repair later on, or something to that effect.

There are so many go here to see most of them http://www.barrytech.com/tektronix/tektm500/tektm500.html
There are alot of the tm5000 series listed on that page as well.

The 500 series plugins will work in a 5000 series mainframe just plug them in but you have to mod the 5000 series modules to work in the 500 series mainframe.
Like this http://www.rbarrios.com/projects/TEK5000/

I would also recommend one of these it was the first thing I purchased after getting mine just make sure you assemble it properly all the connections are in the manuals for the plugins.
http://www.jammaboards.com/store/tektronix-tm500-series-extender-kit-tm500-kit.html

The tm5000 series is more modern like this so some things probably getting into the unobtanium realm.

[linux-works]

I was actually looking for a flexible extender.  thanks!  have you actually used that one?

the real tek version has coax for the non-psu lines.  I wonder if that matters; the plugins I am using or plan to use probably won't do anything across the backplane other than get power; and so it seems ok to me to have a ribbon cable like this and not coax lines (?)

[ahnuts72]

Yes I tried it after I assembled it to make sure it works its probably the only one you will find I looked forever.
The tektronix ones I saw where all ribbon cable.
The tektronix ones are like gold plated platinum wrapped in unobtanium.

(For any one else wondering what the cable is for.)
Its to extend the power outside of the chassis to work on the plugins.
Reach inside and plug one end into the chassis and the plugin into the other end.

Another nice thing is the tm504 and the tm506 where the only ones to have a high power slot the very right slot is capable of supplying 1 amp all others only supply 400mA so if you have a power supply it will only output the maximum current of the slot its in 400mA for all but the right slot 1 amp for it.