BK Precision 2160 Oscilloscope

Aler · Guest

I bought a BK Precision 2160 from ebay that was reported to be in working condition but sold as is. The picture on ebay showed a working scope.
When I got it in the mail it didn't work. (Surprise there huh?)
The symptoms are this:
No output on the CRT. 'Beam Find' doesn't find the beam.
The unit seems to power up, the power led comes on, the trigger led flashes every now and again when I turn a knob or flip a swith.

I have the schematics for the scope but being an electronics newbie they aren't much help without instructions.

Does anyone have suggestions on how to start to troubleshoot this thing?
Thanks in advance,
Aler

Guest · Posted: Sat Apr 22, 2006 3:35 am Post subject:

Does the probe work? Have you connected the probe to the calibration squarewave? Which chanel is the probe connected to and is that chanel switched on? Which triggering option are you using and what level is it set to? What voltage is it set to?

Guest · Posted: Sat Apr 22, 2006 4:26 am Post subject:

I'm totally new to scopes.

Does the probe work? (No. I connected the probe to the BNC plug, connected the grounding clip to the probe, grounded the clip to the chassis and stuck the probe point to the calibration pin)

Have you connected the probe to the calibration squarewave?

Which chanel is the probe connected to and is that chanel switched on? (Channel 1. It is switched on to GND, I switched it DC during testing)

Which triggering option are you using and what level is it set to?
(Auto)

What voltage is it set to?
CH1 0.2V

(I'm in Germany. The Hz is 50. Not sure if that makes a difference or not)

I got a blank screen for all my efforts.

Guest · Posted: Mon Apr 24, 2006 5:21 pm Post subject:

When on GND wind the beam up and down and from left to right, try a different triggering mode (maybe line) and wind the beam up and down, left to right. Change the triggering level and try again.
The user/owners manual should show you how to find the beam, maybe you could find it on the BKPrecision website?
http://www.bkprecision.com/www/NP_d_scopeguide.asp

hermanthegerman · Joined: 01 Feb 2006 Posts: 5

So, if you are from Germany, we could go-on in german: Prüfe mal, ob die Bildröhre überhaupt heizt. Dazu das Gehäuse öffnen, Achtung, im Betrieb führen die Elektroden natürlich hohe Spannung. Ob die Glühkathode arbeitet, sieht man dann im abgedunkeltem Raum, genau wie bei den TVs.

hermanthegerman · Joined: 01 Feb 2006 Posts: 5

Sorry, didn't work:

Pruefe mal, ob die Bildroehre ueberhaupt heizt. Achtung, im Betrieb hohe Spannungen. Im abgedunkelten Raum sieht man dann gut, ob die Heizung der Gluehkathode arbeitet.

Guest · Posted: Thu Apr 27, 2006 5:26 pm Post subject:

I am sure you would have tried turning the 'intensity' up? If you find the beam wind it back down so you can just see the trace or you will burn the phosphors.
Do you have the sweep mode switched to main? Below is the user manual, it has a procedure for finding the beam.

http://www.bkprecision.com/manual/2160A_manua.pdf

Some models have a resistor connecting to the BNC plug, if it was overloaded this could be burnt? Can you test FET's? Any further fault finding should be done by somebody who knows the danger involved, there could be 12 000 Volts present with the unit unplugged.

Let us know how you go.

gridleakrick · Guest

Aler,
Forget all the other advice you have received so far. If pressing the beam finder button does not display a trace then something is seriously wrong internally in the scope. First, check all the power supplies to see if they are putting out the correct voltages. You will need a high voltage probe to check the cathode and accelerator voltages. Be VERY careful as these are thousands of volts!!! The lower voltages can be checked with a standard meter (digital or VOM). Then check to see if the sweep circuits are working. It starts to get rather complicated here so you might want to find someone in your area to give you a hand.
By the way, could I get a copy of your schematics for this scope, please?
If possible, email them to me at gridleakrick--at--yahoo.com (of course, replace --at-- with @).
Thanks,
gridleakrick

Guest

Hello Aler,

Now I am in the same situation with this same type of oscilloscope (I have purchased on Ebay also) but I have no schematic diagram. I can help you in your problem because I have professional level knowledgement in this kind of electronic repairs - and you can help me in my problem. I would need the schematic diagram first of all.

Best Regards,
Jozsef Kovacs
info at realtimecontrol dot hu

hhopkins · Guest

Would someone sell me a copy of the Schematic? I would greatly appreciate it!

Earl