I couldn't end the day with just having the board restoration work complete.
I am always curious whether the audio components will actually work now.
First step was to reinstall the preamplifier and FM boards.
The Beomaster is ready to power on. Like I always do with this type of amplifier I connect the power cord to my variac, ammeter, voltmeter and dim bulb test device. That device will protect against any hidden short to grounds on the power signals and it will tell me if something is drawing too much current.
In this case...I got nothing. No lights, no voltage on the power supplies.
After a bit of investigation I discovered that one of the AC cable wires was not connected internally in the Beomaster. That explains that.
I checked the other wires around it and checked for any shorts. Other than the disconnected AC wire everything else looked fine.
Here is my repair of the broken wire.
That looks much better.
On the second round of the power checks I still don't get any lights illuminating on the Beomaster 4400 but I do have power on the supplies.
Here are the +15 VDC and +35 VDC supply checks
and here are the ±35 VDC rail voltage checks
It looks like the Beomaster 4400 is ready for a quick listening check.
I did a quick, initial setting of the idle current for the output amplifiers by adjusting the left and right channel trimmers to get 10mVDC across the respective channel emitter resistors.
Once those were adjusted I connected an iPod Nano to the Tape 2 source input and used a pair of headphones to check if I had sound.
Success!
I connected up an FM antenna to the Beomaster 4400 antenna input and tried tuning a station.
Another success. The FM tuner section is working great. The tuning indicator and stereo lamps do come on as well.
So for certain the Beomaster 4400 power on lamp is not working and the lamp that illuminates the radicator (the FM signal strength meter) is also not working.
I am not sure about the overload lamp but I can test that when I replace the power on lamp.
Beolover provides professional Bang&Olufsen maintenance and restoration services. We give one year warranty on parts and labor. All parts featured on the blog are available at the Beolover Store. Please, send an email to beolover@gmail.com for inquiries. Enjoy the blog!
Featured Post
Beolover SyncDrive: DC Platter Motor Replacement for Beogram 4002 and 4004 (Type 551x and 552x)
Late Beogram 4002 and the 4004 (Types 551x and 552x), which have DC platter motors instead of the earlier synchronous AC motors usually suff...
Sunday, July 26, 2020
Beomaster 4400 Type 2419: Personal Project: Initial Power Checks
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment
Comments and suggestions are welcome!