Hi,

Maybe this will help;

/forum/general-discussion-and-questions/beolab-4-repair-options#post-2085636

Kind regards

Julian

Hi,

There have been a few threads here on broken BeoLab 4s. I too had a very similar problem, though the led was also pulsing yellow, very faintly.

Bottom line is that a repair is quite costly. Problem with a used set off ebay is that those will probably fail too, sooner rather than later. I did buy a replacement speaker, but the seller had not tried them out for a certain time, and when it arrived, it seemed to have the same problem.

Eventually, I bought a set of M3 speakers to replace my lab 4s. They sound even better in my opinion, and there is still warranty on them. Price-wise, I paid €350 for the set through a second life dealer (for one demo and one brand new speaker). Apart from the line-in which I mostly use, they are also easily paired through bluetooth, airplay or chromecast for wireless streaming.

XavierItzmann wrote:

 

2.  As soon as sound is detected and the light switches to green, the speaker emits an awful high-pitched wobbling sound, with about a 1 or 1.5 second frequency between the low and the high.  No actual music is emitted (that I was able to detect).

This sounds like a defective amplifier and/or powersupply inside. What your hear is a not working well amplifier and after booting the powersupply collaps.

You never know for how long an extra bought pair will work. A fixed BL4 might surpass them..

Thanks Julian. Quite interesting to see so many others have experienced similar issues!

Yes good point!  On eBay these go for about $250/unit... but you are right these are just as likely to fail!

Thank you marry.  I have sent you an e-mail via this system.  Best,

XavierItzmann wrote:

So, do you think this was a defective electronic design on the 4's? 

That is what I made up from reading about it.

Marexy here on the forum has seen plenty of Lab4s with the same problem. He kindly offered to repair mine, but due to transportation costs, it was not an economically feasible operation for me. I was sad to see them go. Design-wise, the M3s are not nearly as good looking as the Lab4s.

At the beginning I fixed these boards (ICE power amplifiers). But to do it properly with a reliable result, the costs to fix (amount of time and parts) doesn't weigh up to the costs of a new board. The older failing boards are always from the older batch series. When newer boards fails in case of a replacement of a previous faulty amplifier, then there has been a problem in the power supply as well, which probably has been overlooked. A unstable power supply increases the changes of a failing amplifier.

The BL 4000mk2 have pretty the same design, but I tend to say that there are a bit less sensitive for failing. 

Switching technology has been used now for more than 15-20 years and might not be as rock-solid working as the old school designs, but it gave some interesting benefits, like less heat dissipation/power-consuming, smaller designs/housings, etc. But probably the combination of high power demand with smaller components increases the changes of failure. And the rush-in current  during startup (plugging in the power) in every device has always been an erratic factor. A example like a lamp which you switch it on and gets shot instantly.

All electronics can fail, you just have to be a bit more lucky that it doesn't happen with yours.