Hi, I have a LeCroy 9450A Oscilloscope.
It has problem about triggering mode.
LeCroy 9450A Oscilloscope displayed "NO or SLOW TRIGGER".
It works well most of times.
But sometime it does not run triggered mode but it run auto mode well.
I can not fix this problem.
Please let me know how to fix this problem without calling maker service.
I have not service manuals for LeCroy 9450A Oscilloscope.
Please give me any advices .

Kishikawa.

that means the scope is not seeing a trigger signal.

the scope may be broken or you may not have it set up right

did you select the trigger source to the channel you are looking at?

Mark

Thank you, Mark.

Yes,scope can not see trigger signals.

I connected ch1 probe to probe calibrator out put whitch built in.
Probe and trigger mode is set to DC coupling mode.
Trigger source is set to ch1.
I set trigger level to half level of Probe calibrator output.
The trigger level is maybe set properly.

In this condition,
Most time LeCroy 9450A Oscilloscope works looks like perfectly.
But occasionaly LeCroy 9450A Oscilloscope lost trigger signals.
LeCroy 9450A Oscilloscope displayed "NO or SLOW TRIGGER".
I do not change any settings.

Then I set to trigger mode to auto.
LeCroy 9450A Oscilloscope display Probe calibrator signal
in free running mode not triggered.
I change trigger level or other condition.
Displayed signal is not changed---free run signal is seen.

I think
LeCroy 9450A Oscilloscope has intermittent trouble in triggered mode.
I want to fix this trouble.

Please Advice me another point.

Thank you Kishikawa.

"Mark" wrote in message
oups.com...
that means the scope is not seeing a trigger signal.

the scope may be broken or you may not have it set up right

did you select the trigger source to the channel you are looking at?

Mark

yep, sounds like a problem in the scope

check for a loose connector or something simple, more than that and
you will need a schematic

Mark

Thank you,Mark.

Yes,there are any problem in LeCroy 9450A Oscilloscope.

After problem found.
I have checked loosen connector,IC in sockets,built in batteries.
I could not found anything wrong except low batteries(I already changed).
Trigger mode problem is not solved.

Maybe LeCroy 9450A Oscilloscope or similar type has same problem.
There are 4 Lecroy Oscilloscopes near my sights.
3 of 4 Lecroy Oscilloscopes are in trigger mode problem same as mine.

I have not service manuals or schematic diagrams for LeCroy 9450A
Oscilloscope.
Someone experienced same problem which already fixed.

So,I want any advice to fix problem.

Thank you Kishikawa

"Mark" wrote in message
oups.com...
yep, sounds like a problem in the scope

check for a loose connector or something simple, more than that and
you will need a schematic

Mark

Thank you All.

I maybe fixed LeCroy 9450A Oscilloscope problems.

1.100MHz Xtal is poor ---- change to 100MHz Xtal OSC.

2.ECL power supply is -3.6V ---- correct to -5.0V.
Variable resister for voltage adjustment in power supply unit is bad.

Thank you Kishikawa