Marantz 4400 oscilloscope does not display - AVS Forum | Home Theater Discussions And Reviews

Forum Jump: 
Thread Tools
Old 02-29-2012, 03:53 PM - Thread Starter
Josea's Avatar
Join Date: Feb 2012
Location: Swarthmore, PA
Posts: 97
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
My 4400 works great except for the oscilloscope. When i turn it on it is a faint orange color, but none of the functions (such as FM tuning) show up on the scope rendering it useless. I can provide a picture if needed. I do not want to replace this unit, it has great sentimental value. When it worked it was green color as far as I recall.
The attachment is how it should look, I get no green color now
I appreciate any suggestions, I am willing to take off the cover and 'tinker' if necessary.

Josea is offline  
Sponsored Links
Old 02-29-2012, 04:12 PM
AVS Addicted Member
Join Date: Dec 2005
Posts: 13,434
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 12
Not that I have any suggestions for you on it, but dang that is a cool oldie but goodie ya got there.
JOHNnDENVER is offline  
Old 02-29-2012, 08:58 PM
Advanced Member
juancmjr's Avatar
Join Date: Dec 2006
Location: Santa Rosa, CA
Posts: 907
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 10
I don't have the absolute answer for you but at almost 40 years old it's possible that the CRT has burned out and obviously you'll need a new one. Not sure where to get a replacement or if any would be available NOS or used. I recently came into possession of a 4400 in need of restoration.

Occupation: Millionaire Philanderer... I mean philanthropist

juancmjr is offline  
Old 02-29-2012, 09:00 PM
AVS Special Member
DonH50's Avatar
Join Date: Feb 2010
Location: Monument CO
Posts: 9,322
Mentioned: 23 Post(s)
Tagged: 0 Thread(s)
Quoted: 1662 Post(s)
Liked: 1205
You'll have to get it serviced unless you know how to do it yourself. There is high voltage (~kV) on the tube so don't mess with it if you don't know what you're doing. The bad news is it could be very hard to find replacement parts... Orange glow could mean the filament is OK but the HV supply or sweep circuits have fried.

"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley
DonH50 is online now  
Sponsored Links
Thread Tools

Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off