Lecroy 9400

Hi
After 3 years my Lecroy 9400 has died. It no longer responds to the
front panel or GPIB. Everything still works but the settings are stuck
and can`t be changed. There is a red LED glowing on the main board
which I guess is a fault indication. My gut reaction is that a clock
has stopped oscillating but where to start???

Any help appreciated.

 

Many thanks for the response.
I see what you`re getting at. Where are you looking for signals on the
rear panel?? At one of the RS ports or the GPIB??
Had a poke around with another scope and find that both crystals are
operating....although did `nt know there were PLLs on board.

Thanks for the tip on that LED....I`m certain it does n`t
blink....maybe confirmation that front panel signals are not getting
through.

A schematic is the answer I think.



Nick

kishikawa wrote:

Hellow Nick,

I have Lecroy 9450A having some trouble.
But most of time it works properly.

There is a red LED on front panel interface board(main board?).
Red LED is glowing,it blinks when changing front panel settings.
Maybe LED glowing means not fault.

I guess clock is not setted properly maybe PLL circuit is in problem.
So cpu is waiting until clock setted signal.

If you have another Oscilloscope.
Check clock out signals in rear panel.
My Oscilloscope does not output any signals when troubled.
But when Oscilloscope works well there are clock out signals.

Your trouble is very similar to my trouble.
Most of my trouble is not triggered.
But rarely I can not change front panel setting as your trouble.

I am shooting this trouble.
But I have not schematic diagrams,service manuals.
Have you any advice?

Thank you Kishikawa

nick.kenworthy@ntlworld.com> wrote in message
news:1112044072.059861.151050@z14g2000cwz.googlegroups.com...
Hi
After 3 years my Lecroy 9400 has died. It no longer responds to the
front panel or GPIB. Everything still works but the settings are
stuck
and can`t be changed. There is a red LED glowing on the main board
which I guess is a fault indication. My gut reaction is that a
clock
has stopped oscillating but where to start???

Any help appreciated.