I have an Hitachi V-1050f oscilloscope. I have lost the ability to trigger the scope. Does anyone know where I can get some help to get it repaired. I have the service manual and I have located the triggering system but I really don't know how the scope works. Any guidance is appreciated.

 

Are you certain that it is an internal circuit problem and not simply a wrong setting on the front panel?

What are your settings on the trigger section?
Can you get a line on the screen?
Have you tried feeding a signal into the trigger input?

 

The trigger settings are correct. I have had and used this scope for about 20 years. It will not trigger on an input signal ( sine wave, sq.wave, ramp, etc....... I probed around a from the trigger level pot on the front panel, all the way back to an op amp in the triggering system. When I turn the trigger level pot, i can see variation on the op amp. I do not know enough about how the system works to really know to look further.

 

If you can provide a link to the service manual I might be able to help.

 

http://www.eserviceinfo.com/downloadsm/11460/Hitachi_V-1050.html

Here is the link to the Manual. "I want to thank you for your efforts"!! There are 5 "MultiParts" (Multipart: 0 1 2 3 4) You double click on "0" and download, then
"1"...."2"...etc until you have all five zip files. Then you can unzip the file and you get the entire manual. Kind of funny but you'll see. Thanks again....

Steve

 

http://www.eserviceinfo.com/downloadsm/11460/Hitachi_V-1050.html


Multipart: 0 1 2 3 4

 

Does it fail to trigger on both internal (Chan 1 or 2) and external triggers?

 

Yes. I found an interesting article about the Triggering System. My problem may be with the Horizontal Sweep, I am still reading. Anyway, you have any ideas?

 

I have noticed something kind of interesting. Initially, I was working on a circuit, looking at wave forms on a bread board, no problems. On the scopes "A TRIG LEVEL" knob, I pulled the knob out for - slope. This is when my problem started. I lost the ability to trigger.

I have some kind of issue with this "A TRIG LEVEL" POT. Right now the trigger is working, but if I go to a -slope setting, I lose the trigger again. I am able to get it back by changing the mode setting from AUTO to NORM and playing with the POT till I get a trace to run, then it starts to work again. Would like understand what is happening.

It's probably time to get another scope!!