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,
I was running some music through my Beomaster 5000 for about 30 minutes, at loud volumes something like 4.2, driving a pair of CX100 and a pair of Beovox Pentas. I felt the heat sinks and could not hold my finger against them for more than a second. I estimate the temperature was 60°C. The hottest were to the left of the BM when looking from the front.
Is this considered normal?
The unit was originally shutting off after 20 seconds as the two pre-sets needed renewing, which I completed. The circuits had to be set to 11.2 mV, which I did to the best of my abilities using a somewhat simple multimeter.
According to the design notes,the cooling fan should start up at 50 degrees,and be going full tilt if the heatsink reaches 95!!!!
Often,the fan system is u/s.It suffers from failure of capacitors,and also the temperature sensor thermistor mounted to monitor the heatsink temperature.
There is another system in place to protect the amplifier though! An auto volume control limiter that actually turns the level down if the amplifier is overloaded.
It's most likely that the fan system in your Beomaster is not functioning,but also you need to look at why it's overheating.
This could be instability caused by dried out capacitors etc.
Regards,
Nick
Many thanks for the reply.
Actually, your first line is probably reassuring. I estimate the temp is 60°C. Therefore, am I seeing normal operating temperatures?
Can the system run between 50 and 95°C normally?
Is there something wrong if the fan operates or is this normal?
How can I tell if the fan is operating?
cheers
In my experience it's very rare for the fan to operate,except when the unit is under excess load,or poorly ventilated,say when confined inside furniture etc.
You'll remember when you replaced the output stage presets,that the section is covered by a plastic cowl.The fan blows into this and forces cooling air over the amplifier and heatsink until the temperature drops when it switches off again.It's quite quiet,but you will feel the hot draft at the rear of the unit.
The protection is built into the design in view of the low profile styling,and the possibility of system 5000 components being stacked.Also with several link rooms connected, the load on the amplifier would be increased.
The Beomaster 5000 and it's derivatives 55,65 and 7000,have proved to be robust and reliable over the years.
I suspect that your Beomaster needs a "re-cap" if it's getting hot.Does the unit overheat in any particular mode,say when using phono?
Beoworld member Dillen can no doubt help with a capacitor kit
Many thanks for all the info.
The speakers are a pair of CX100 and a pair of Beovox Pentas. I was listening to a CD at the time. Do you have a 5000 unit? If playing fairly loud, do your heat sinks feel hot to touch?
My thinking is that if the fan operates at 50°C, I'm probably feeling about this temperature, I'm still within sensible operating temperatures.
What I'm asking is that do you heat sinks just feel warm, or do they get quite hot when playing fairly loud? I'm trying to find out what would be considered normal? If the fan is running, is it obvious? Do you feel air flow at a particular position at the rear of the amp?
Beomaster 5000 gets warm at the cooling fins when playing. That's normal.If you can touch the cooling fin, it's not more than 60 degC or so and all is fine.
Martin
I do have a BM5000,but no Pentavox speaker's alas!
The heatsink/cooling fin's will of course get hot,that's what they are for,but I know what you mean,and it's a bit like asking "how long is a piece of string"?
Certainly if you can't touch the heatsink fins and there is no apparent warm(hot?) draft blowing out around them,there would seem to be a problem.
Rest assured that these are robust designs and well proven now.
I've found that owning a little IR thermometer, the type with a laser to aim that you point at things to read their temperatures to be an invaluable thing, even just for amusement. I use it often in the kitchen to read the temperature of pans and grills to make sure they are hot enough (I regularly, when searing steaks and such, get my cast iron skillet up to 500+ deg F). Also very useful for reading temps of electronics. Not expensive, and it's also just fun to wander around and randomly see what temps things are, good way to look for where your insulation in the walls or ceilings may not be up to snuff.
Jeff
I'm afraid I'm recovering from the BeoVirus.