ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hello everyone!
This is my first post here in this forum. Previously I had no experience (or never heard of) the brand B&O, until a few hours earlier when I was cruising around the local second-hand shops, I found a B&O Beomaster 4400 unit which seems to be in pretty classy styling and good cosmetic condition, however the shop owner claimed the unit was 'non-functioning and for collectors only', nevertheless I purchased it, just for research and maybe, scavenging for parts. Upon searching the internet I found this website and it's amazed to see there are so many people are dedicated to this brand, which is danish (quite surprised that this brand actually survived to this very day)
Disassembly indicates that my unit has never been tinkered before, the interior is so dusty that flowers may be planted in the bottom plate, no kidding. Fuses are original and aren't blown. However I measured the resistance between the AC plugs it was barely 4.5 ohms, which I suspect is abnormal, maybe an indicator of some severe short circuit, so I dare not to plug it. Can anyone verify this by telling me the AC resistance of a working 4400 unit?
Hi,
Welcome to Beoworld!
The Beomaster 4400 is considered by many as one of the best receivers of the marque. It is also very good in absolute terms, and to my ears at least, better than many Japanese receivers of the time, which were all lights and buttons but not necessarily very good at all!
So yes this one is certainly worth renovating! Don't you dare scavenging it for parts!
My own 4400 measures about 47 Ω when Phono - or any other input - is depressed.
Do the switches seem to operate normally, firmly? Any photos perhaps?
PS: CCTV? Really?
Jacques
Thanks for your reply, chartz! All switchs in this unit seems to be clicky, good condition
Upon further observation I found most loads on 4400 may be disconnected from the power supply via connectors, I unplugged all visible ones (including the power output amp for 2 channels), however it's still only 4,5ohm between AC input plugs, ten times afar from your working unit (47Ω)! However the power components are located in a discrete shielded metal box which I do not have time to dismantle today...
So I guess this unit could have suffered a faulty power supply (bad main AC transformer or recitifier bridge - or a leaky power capacitor) but under those circumstances, fuses should have blown once plugged in, and I'm almost sure the owner of the secondhand shop must have plugged and tested (if he verified the machine as a working unit, he would be able to charge MUCH more), yet no smells of burnt inside. I just know smells of electric burnt can last for 10+ years if you move your nose close, but in my unit there is only smells of dust.
What you "see" is the transformer's primary winding, so whatever you unplug on the other side has no influence on that winding's resistance, since primary (the 240V winding) and secondary windings (coils) are galvanically insulated.
Do have a look at that ominous voltage selector!
Good reasoning. I rotated the input voltage selector, and when '110V' is selected the ohm resistance reads 2.1ohm or so, about halved compared to '240V' setting. So the voltage selector is working, it is highly probable the transformer itself is faulty (partial shortage, maybe bad insulation paint, in the input side but not completely down to 0ohm so that fuses are not fried yet.)