Beolab 8000 signal sense circuitry fail

9 replies
O(
Offline
OFFICERTOM (archived2)
Bronze
Posted December 18, 2015 at 20:40 GMT
#2055285

I have had a pair of Beolab 8000 last 15 years working perfectly but suddenly one of them it has stopped working.

The red led is ON all the time.

When I turn on the music, the right  Beolab 8000 gets ON, led on green, and sounds but the left one remains OFF with the led on red. 

I have interchanged the wires between the speakers to check if it was a problem of the Beovision 5 powerlink output, but the right speaker works perfectly on both Beovision 5 powerlink outputs.

I have connected my iPhone to the LINE input on the broken left speaker (and turn the switch to LINE) and the speaker led remains red nevertheless it turns green and plays the iPhone music on the right speaker when connected to the LINE input.

Can it be a problem in the signal sense circuitry of the speaker? If so, is there a fuse or I must take the speaker to my dealer?

Please help

BI
Offline
bigbruggsy
Bronze
Posted May 9, 2019 at 18:14 GMT
#2055286

Hi Officertom, did you ever get this fixed? I have the same issue with my beolab 8000's.

BI
Offline
bigbruggsy
Bronze
Posted May 10, 2019 at 10:47 GMT
#2055287

Hi Frog, I've looked inside and even though mine are mk1's they have nice white foam inside. Maybe changed previously? But it was all clean inside. I might check the circuit boards closer as previously I didn't notice any corrosion. I thought the issue might be the "switching" on in powerlink mode, as it works in "line in" mode. And the issue is not from the source as I've swapped speakers and the issue stays with the one speaker.

Beobuddy
Offline
Beobuddy
BronzeFounder
Posted May 10, 2019 at 11:35 GMT
#2055288

With what number starts your serielnumber?

I’ve seen several BL8000’s where they attemped to clean and placed new foam. But the cleaning wasn’t done properly with the same result. 

Location: Utrecht

Quite a challenge to achieve "Less is More" while having the Beovirus.
BI
Offline
bigbruggsy
Bronze
Posted May 10, 2019 at 19:34 GMT
#2055289

Hi Beobuddy the serial numbers are 16811333 and 17693279 ( I have 2 pairs, with 3 of the 4 speakers having this issue)

KE
Offline
keepitcomplicated
Bronze
Posted August 13, 2019 at 10:35 GMT
#2055290

Did you manage to figure out what was causing the issue?

MH
Offline
Martin Hemmi
Bronze
Posted September 10, 2021 at 13:08 GMT
#2055291

I had the same problem. I found out that TR11 was broken. It is the low side switch for the relay that turns on power. To be safe I changed TR9, too. Maybe a protection diode could have helped. The circuitry that either switches on signal input or the switching voltage works on switching logic of 5V (the audio signal is amplified to 5V and then logically connected to the other logic levels that can switch power off (temperature, tweeter protection).

T(
Offline
tkona (archived2)
Bronze
Posted October 31, 2021 at 01:25 GMT
#2055292

Hi Martin,

I was wondering if your fault on the auto start circuit on the  TR 11 was intermittent?

I seem to have a similar issue . Once I dismantle the amp module and start bench testing for some reason it starts working again but it stops after few days.I was just wondering if this is maybe linked to the intermittent issue related to TR11 . All my PCB tracks around the power relay are fine . It is definitely a auto start issue. Also when the amp works I can trigger a temp overload that means that the circuit around TR-7 and TR-8 is working fine .

Thanks

T(
Offline
tkona (archived2)
Bronze
Posted October 31, 2021 at 01:26 GMT
#2055293

Hi Martin,

I was wondering if your fault on the auto start circuit on the  TR 11 was intermittent?

I seem to have a similar issue . Once I dismantle the amp module and start bench testing for some reason it starts working again but it stops after few days.I was just wondering if this is maybe linked to the intermittent issue related to TR11 . All my PCB tracks around the power relay are fine . It is definitely a auto start issue. Also when the amp works I can trigger a temp overload that means that the circuit around TR-7 and TR-8 is working fine .

Thanks

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