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
Hi, new to the site here and looking for a bit of guidance from the more tech savvy and experienced here.
I bought a 5500 series last year with amp/tuner, cd player, tape deck, linear turntable etc and put it in storage until I had time to get it properly set up. Big mistake! Had I known that it was faulty I could have claimed a refund but it's now too late.
The cd, phono, and tape deck seem to be working fine but initially I had to get the speakers repaired due to the outer support rings being disintegrate. I understand that this is a common issue and it wasn't an expensive repair.
Once I received the speakers back and set everything up, it was obvious that the Beomaster unit was not behaving correctly. The audio signals from all external devices were not being amplified to the speakers. After some fault finding, I discovered that the 40, - 40, 13, 12, -12, 8 and 5 Volt rails were all missing. This lead me to the standby/power on relay which was toast. Found a replacement and installed it but I noticed that the 8V rail is now a 10.5 V rail. All other DC voltages appear to be very close to the specs. The relay is switching on and off correctly but the 6V coil has 8V across it due to the high 8V rail voltage when in standby mode.
The amplifier works fine for a short time of perhaps 30 seconds and then shuts down. I noticed that two of the smaller transistors bolted to the rear heatsink are getting up to +40 Deg C before the shutdown occurs.
Has anyone else here experienced similar problems?
Any advice will be greatly appreciated.
Time was on my side!
Sorry to hear about your 5500.
I've recently killed a BeoMaster 7000 with a fault in the same region of the board. Have a look here,
https://archivedforum2.beoworld.org/forums/p/42092/307257.aspx#307257
Bits just explode off the heatsink now!
Given the age of the amp I'd suspect all the power supply capacitors. Also check how you are measuring the voltages. A very good true RMS multimeter may tell you more than a simple voltmeter. Measure the DC voltages on the AC range. Any more than a few mV is too much. Some meters will add the AC ripple to the underlying DC voltage. High ripple replace capacitors.
What are the numbers of the small transistors that are getting hot? I've got the circuit diagram for a 6000 here. It's much the same out the back end of the amp.
Good Luck, you'll need it.
Baegle ( I'm near Lithgow NSW)