tek 2215

• #25 Reply
  Posted by andy3055 on 22 Oct, 2021 06:26
• Yeah, those are protected files. Check pdf page 157.
• #26 Reply
  Posted by m3vuv on 22 Oct, 2021 06:41
• it gives the location as beeing 2 c,is that on the board with all the controls on,gives a pic of the front pannel board on this manual.
• #27 Reply
  Posted by andy3055 on 22 Oct, 2021 06:54
• Get this manual: https://w140.com/tekwiki/images/9/9a/070-3826-00.pdf
  
  Page 157 has the Vertical preamps.
• #28 Reply
  Posted by m3vuv on 22 Oct, 2021 07:35
• it gives the location as 2c,is that on the board with all the controls on it,ie the front panel board?
• #29 Reply
  Posted by andy3055 on 22 Oct, 2021 08:08
• Check page 156. It is on the A10 main board towards the bottom left. Location 2C area.
  
  I saw your posts on Tek Groups.io. Did you try the responses from those people?
  
  It is just past 1 AM for me in the bay area. I am going to sleep. Will catch up in the morning. Brain does not function at this hour!
• #30 Reply
  Posted by m3vuv on 22 Oct, 2021 08:53
• well i have found them,again a total ass to get to with the crt in situ,looks an ass of a job to remove the crt,it may get put back together and go on ebay as spares or repair,cheers for the help,the tek group io have been no use whatsoever! .
• #31 Reply
  Posted by andy3055 on 22 Oct, 2021 22:12
• I still think you should check the voltages per the service manual on that section. I get the feeling that something has failed there. Since it does this on both channels, it has to be a common thing like power for both channels.
  
  There are some good tips on this thread: https://www.eevblog.com/forum/repair/tek-2215-repair/msg2508945/#msg2508945
• #32 Reply
  Posted by m3vuv on 24 Oct, 2021 01:17
• does anyone know where the voltage test poins are located on this,all i can see is a ground tag/tp.
• #33 Reply
  Posted by m3vuv on 24 Oct, 2021 02:06
•  i located the test points under the psu cover,they all read within 100mv of what the service manual states.
• #34 Reply
  Posted by andy3055 on 24 Oct, 2021 02:24
• Even though the test points have the specified voltages, check the transistors and make sure they have the correct voltages.
  
• #35 Reply
  Posted by m3vuv on 24 Oct, 2021 02:42
• thats the next step,trouble is they are total bastards to get to with the crt in the scope,may have to remove it but that looks a major task in itself.
• #36 Reply
  Posted by m3vuv on 24 Oct, 2021 03:14
• Wel i have the crt removed,wasnt a big job infact,thing is is it safe to turn the scope on without the crt in it,or is the eht gonna spark all over the place and kill things,or should i just reconnect the eht to the tube and fire it up?.
• #37 Reply
  Posted by m3vuv on 24 Oct, 2021 03:47
• well while i was in there i thought i would check some caps for esr,there are what look like tantalum caps,see pic by the tip of red probe,is that a tant cap?if so it reads infinity.

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• #38 Reply
  Posted by David Hess on 24 Oct, 2021 04:05
• That is a polystyrene or possibly polycarbonate plastic film capacitor.  Ignore it.  It reads infinity because it has a low value of capacitance.
  
  
• #39 Reply
  Posted by andy3055 on 24 Oct, 2021 04:18
• I would follow the diagram instead of just checking random components because it tends to make you deviate from what you are after.
• #40 Reply
  Posted by m3vuv on 24 Oct, 2021 04:42
• i took it out and measured it,its fine,i have just ordered a solder heat gun to remove the transistors and test them,with it being a double sided board i feel i will lift tracks etc,also need to know if i can power this up with the crt removed,or possibly with just the eht connected?
• #41 Reply
  Posted by jonpaul on 24 Oct, 2021 05:42
• Bonjour
  
  
  A bit puzzling to read all of these notes from  m3vuv and similar posts on 2215 on the excellent TekScopes Groups .io,
  I can only wonder why the complete and correct version of the manual and schematics is not easily available?
  
  I suggest to follow a logical troubleshooting procedure.
  
  Finally as an active contrib on both EEVblog and groups.io TekScopes, i can highly recommend the TekScopes and very surprized that it seems unresponsive to this thread.
  
  
  Bon Chance,
  
  Jon
  
  
  
  
• #42 Reply
  Posted by m3vuv on 24 Oct, 2021 06:26
• Hi jon,im supprised by the lack of responce from the tek io groupe,my main issue is running the scope to check transistor base voltages in the vert amp section with the crt removed as its nearly imposible to probe them with the crt in the scope,but im wondering if i power it up without the tube in,will the eht rise to crazy levels and kill something,thats where i am at  at this moment in time,sort of chicken and egg,i have the correct manual,but on a pdf its hard going,i much prefer paper! 73 m3vuv.
• #43 Reply
  Posted by m3vuv on 24 Oct, 2021 15:07
• is it safe to power the scope up with the crt removed to take measurments?,as stuck until i get advice on doing this.tia.
• #44 Reply
  Posted by Ground_Loop on 24 Oct, 2021 15:41
• With no input signal and the input switch set to GND can the trace be positioned in the center of the CRT?
• #45 Reply
  Posted by m3vuv on 24 Oct, 2021 18:09
• FFS cant you guys read my last post!!!!
• #46 Reply
  Posted by Ground_Loop on 25 Oct, 2021 00:28
• Quote from: m3vuv on 24 Oct, 2021 18:09

  FFS cant you guys read my last post!!!!
  

  
  I was just asking to see if you had tried it before taking the CRT out.  Anyway, I doubt anyone is going to tell you it's safe to run the scope with the CRT disconnected and I hope the reason is obvious.  Try it, see what happens.
• #47 Reply
  Posted by bdunham7 on 25 Oct, 2021 03:52
• Quote from: m3vuv on 24 Oct, 2021 15:07

  is it safe to power the scope up with the crt removed to take measurments?,as stuck until i get advice on doing this.tia.
  

  
  I've never run one without a CRT in it so I can't be completely sure that nothing will burn up due to no load, but I don't know what it would be.  As for personal safety, there's about -2000V on some of the CRT socket terminals, about +10kV on the red wire that you disconnected from the front of the CRT and a few hundred volts or so on the 4 wires you disconnected from the middle of the CRT.  I'd be super careful not to let any of those short out on anything, especially the horizontal and vertical deflection wires..  Usually I can do everything I need as far as testing from underneath, but if that isn't practical and you want to do it with the CRT out, I wouldn't go probing around a live board.  Connect up with test clips, then power on and be sure to power off and wait a bit before moving on.
• #48 Reply
  Posted by m3vuv on 25 Oct, 2021 05:59
• Well i hooked up the eht to the crt and moved the whole lot to one side,heres a few readings i took,on q387 base i get 8.8v,it should be 2.6!,r290 wiper measures as follows,fully cw=3.44,fully ccw 3.4v,r190 is fully cw3.4,fully ccw 3.4v,dont know if this helps?
• #49 Reply
  Posted by m3vuv on 25 Oct, 2021 06:01
• groundloop,with both inputs set to ground and no input the furthest up the screen i can get both traces is about 2 divisions from the bottom of the screen.