Well I went and got the lot of stuff from my neighbor. Some good some not so good.
The Tek 465 powers up but the display does nothing. I am hoping it is something simple from it being in storage for a few years. Does anyone have an idea what to check?
I need to hook up the frequency counter and test it.
a yankee living in the hind end of the bible belt
some people are like slinkys, not really good for anything, but still bring a smile to your face when you push them down the stairs.
What are the power supply voltages like?
Get hold of a service manual and verify each . Most Tek scopes of the era have +5, +/-15 and a +/-50v outputs off the main PSU header; all other voltages are derived from those.
Start by isolating the PSU board from the rest of the scope. If all checks out, reconnect the power headers and proceed with troubleshooting. If not...the likely culprit is a bad electrolytic filter cap.
For that matter, one of the many tantalum decoupling/despiking capacitors used on the various subassemblies may have gone bad and is drawing the respective supply line to ground.
That's what ails most of the Tek scopes I've worked on lately.
Check the supply and let us know what you find out.
"Everyone wants to be an AM Gangsta until it's time to start doing AM Gangsta shit."
Before you do anything, go here young man, go here :
http://www.ko4bb.com/manuals/index.p...Service_Manual
I will have to do that. I got a bunch of radio parts in the lot also (caps, transistors and IC's) I might even have the parts to fix it when I find the issue...Originally Posted by N8YX
I spent most of this afternoon setting up a board for model trains in the 11 yo's room. This morning was spent verifying that my daughters car was running right again.
Thanks for the starting points
a yankee living in the hind end of the bible belt
some people are like slinkys, not really good for anything, but still bring a smile to your face when you push them down the stairs.
If you don't, I probably do - or can point you off to a source for them.
"Everyone wants to be an AM Gangsta until it's time to start doing AM Gangsta shit."
Have you pressed the beam finder button? If you press that and have the intensity up, I think it needs repaired.
As stated above, a quick push of the beam finder will tell you a lot. If it works, it will confirm the HV is present, and most of the crt operating parameters are close. PS and HV section failures are where I have found most scope problems. And check it in a darkened room because you can see even the faintest phoper glow that you might miss in a bright room. And as Fred states, the power supply branches should be next. Once you can some light on the screen, you can work on the deflection and signal processing circuits, if needed. For what it's worth, over the years I've developed my troubleshooting techniques to begin with a thorough visual inspection with good lighting and some magnification. You will find you can fix a hell of a lot of stuff just by doing that. Obvious things like smoked parts, burned or cracked traces, shitty connections (that's a technical term) and stuff like that. On a scope or any crt equipment, after the visual, I try all the controls and push buttons looking for anything that feels suspicious, then head to the power supply and HV section. Also getting the readings around the crt is a good idea in case of a failure of something like a bias resistor, something in the brightness circuit, or something else that would keep the tube from from conducting. Once you get passed that it's just a matter of going through the sweep and vert circuits. Be sure to take advantage of the calibrated 1 vpp terminal used to put the scope probe to calibrate the vertical deflection. It makes a very handy signal source. Naturally, use a DVM or other scope to make sure the 1vpp or there abouts is present, first. Level isn't important until you go through the calibration. And that brings up another thing I've learned at the school of hard knox. Many times, just following the calibration instructions will get you in the right area. If as you are following the OEM cal sequence, (and block diagrams) you find something that is grossly off, you will find it a great place to start looking around, and then after a little detective work, you will be where you need to be. At this point, it behooves one to make sure the defective area doesn't share a common connection with another circuit, sometimes even on another board. This, in technical circles, is called chasing your tail; or, if you're a ham, frogging your dong.
Good luck with the challenge. You will prevail.
A clear conscience is usually a sign of a bad memory
RIP ALBI-W3MIV RIP RUSS-W5RB RIP BOB-VK3ZL
A challenge it will be. A dark room will be the first test. The garage with the door open and afternoon sun shining in was very bright. I was told it was working when put in storage between 5 and 10 years ago.
If I get it working and I can unload the amps and antennas I got in the lot I will have a scope on the cheap. I will start digging into it in the morning...
a yankee living in the hind end of the bible belt
some people are like slinkys, not really good for anything, but still bring a smile to your face when you push them down the stairs.
Jerry's comment about the beam finder is definitely relevant, especially in light of:
If you can see anything upon a press of the beam finder button I suspect dirty focus, intensity and trigger level pots, especially the latter if you don't have a sweep.
An FYI:
On many Tek scopes, the deflection, CRT filament and CRT high voltages are derived from a DC-DC converter which is powered from the 5V section of the supply. There is a very narrow voltage range in which the converter will oscillate properly and supply primary power to the HV transformer - from which all of those voltages are obtained. If the 5V supply is above or below those tolerances, you'll get nothing.
A quick way to see if all is in order with regards to that portion of the circuit is to remove the scope's covers and check for the presence of an illuminated CRT filament. If it isn't, start with the 5V supply. If it is, have a look at those pots. A little DeOxIt "FaderLube" will help restore operation.
Disclaimer:
There are voltages on the CRT anode which will kill your ass very dead should you come into contact with them. If you for any reason have to remove the HV supply and/or the CRT, be VERY mindful of Tek's procedure for disconnecting the anode lead and discharging the tube. And do so with the unit unplugged from the wall.
You may find the following to be of great help. It was written by your scope's manufacturer:
http://www.sphere.bc.ca/test/tek-par...ing-scopes.pdf
"Everyone wants to be an AM Gangsta until it's time to start doing AM Gangsta shit."
Powered it up last night in the dark and zilch, nada, nothing. I will start with checking the 5v supply in a few..
Thanks for the warning on the HV on the CRT. It is always good to have a reminder.
a yankee living in the hind end of the bible belt
some people are like slinkys, not really good for anything, but still bring a smile to your face when you push them down the stairs.
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