Tektronix 2215 repair project.

[Six_Shooter]

Well, today I received a non-operational Tektronix 2215 Oscilloscope that I plan to repair, or at least attempt to. Either way it was worth the small cash outlay to get it here and learn from this even if I don't get it working.

I knew that certain pieces internally were going to be loose, so I didn't even bother with trying to power it up, I just opened it up to see what I could see, this is my fist analog 'scope afterall.

On the preregulator board I found a broken leg on a MOSFET, I will likely outright replace this, but might try just joining the leg back together, since there's space to do so.

The other thing I have found so far is something on the main board I have not been able to identify what it is. I will upload a picture of it later, but it seems to be made of glass and almost looks like a small lamp.

I have found this item on the schematic found in the service manual, and don't recognize the symbol and have not been able to find the same symbol online to tell me what it is.

Can someone recognize this symbol and help in determining a sutable replacement?

It is DS856 the attached schematic, DS854 seems to be an identical piece.

 

[OLIVE2222]

looks to be gaz discharge tube symbol

http://www.ttieurope.com/docs/IO/6867/Bourns1.pdf

For the value I guess this is stated in the service manual part list

Olivier

 

[davenn]

Neon lamps they are !!

six shooter ... why do you think they need replacing ??
the chances of them being faulty is a million to one unless actually physically damaged ... beoken glass or wire leg

Dave

 

[OLIVE2222]

Thank you for the correction Dave !
Indeed gaz discharge tube have small triangles inside the symbol, absent here

Olivier

 

[Six_Shooter]

davenn, it needs to be replaced, physical damage.

Thank you, so I wasn't far off with thinking they are some sort of lamp.

I haven't found actual values in the service manual, but I haven't read it line for line either. There might be some sort of code I haven't come across yet.

 

[OLIVE2222]

I find out a service manual with stated "LAMP,GLOW:90V,0.3MA.AID-T,WIRE LD" for 3 of them however the designators are not the same (DS856,858 and 870)

Olivier

 

[tryppyr]

Looks to me like all the parts are individually and sequentially numbered. That would allow a replacement parts list to be keyed by the number only, not requiring a part type designator.

 

[Six_Shooter]

Looks to me like all the parts are individually and sequentially numbered. That would allow a replacement parts list to be keyed by the number only, not requiring a part type designator.

I don't follow this.

I see that each board has a listing of parts for that board, to find them on the schematic, but not a list of what they are. Some items seem to be labeled on the schematic however.

I'm going to look through the service manuals I have again, to see if I can find the specs on this particular part.

The one thing that bothers me, is that in the service manual it shows a current limit board, but I can not locate this in my 'scope and wonder if it's missing, though I can't find a location for it exactly, or how it might electrically connect into the scope. One service manual it looked like it could be a board that is soldered perpendicular to teh main board and attached directly to the main board. It doesn't seem like anything is missing in that area.

 

[davenn]

olivier has already givent you the details from the service manual .... did you not read his post ?


Dave

PS
Neon globes with a 90V strike is pretty standard
should be real easy to find from a decent electronics supplier

 

[davenn]

I find out a service manual with stated "LAMP,GLOW:90V,0.3MA.AID-T,WIRE LD" for 3 of them however the designators are not the same (DS856,858 and 870)

Olivier

the designators are there in the parts list, there's just a secret to reading it
read the introduction notes to the parts list

Dave

 

[Six_Shooter]

olivier has already givent you the details from the service manual .... did you not read his post ?


Dave

PS
Neon globes with a 90V strike is pretty standard
should be real easy to find from a decent electronics supplier

I did read his post, I'm just not seeing where that is in the service manuals I have.

the designators are there in the parts list, there's just a secret to reading it
read the introduction notes to the parts list

Dave

I'm reading through some of it again, like I said I haven't read this word for word, and have issues with this sort of document on a computer screen. I need to print it out to be able to use it easier.

--==EDIT==--

After looking at the Service manual some more and figuring out how to open two of the same .pdf at the same time, I was able to locate the part in the parts list.

Thank you.

 

[Six_Shooter]

Just posting a few pictures:

 

[davenn]

if you get really stuck trying to fix it, that's an excellent tektronix forum on yahoo groups
http://groups.yahoo.com/group/TekScopes/

I have belonged to it for a number of years

cheers
Dave

 

[Six_Shooter]

Cool, I don't have a Yahoo account, but if I really get stuck, I'll consider it. lol

At this point I just want to repair what I know is wrong and then move on from there.

I'm considering buying another broken, or at least damaged but looks to be functioning 2215 from ebay, and combine the two, but would rather do that as a last resort.

 

[OLIVE2222]

Hi,

You can find the globes here:
http://be.mouser.com/ProductDetail/Chicago-Miniature/A9A/?qs=sGAEpiMZZMsEIsGLxVc9kMj9z82SfnH7

and here

http://fr.mouser.com/ProductDetail/...=/ha2pyFadugTPK7BO86yQeNNXdx7eMwqpKmOoyecnwA=

the FET looks easy to repair

Olivier