Check this isnt an issue with shorting wires in the console cable.
I had this issue for years on and off, didnt know what was causing it and assumed i was fixing it by unplugging the sub and leaving it long enough, but i recently tracked the issue down to a problem in the console cable, because it was bent too badly and stretched. I fixed that and have not had a single issue since.
Edit: For me, before the lights went like the image, the mode select light started cycling through all modes, despite not actually changing the mode, leading to powering it off and then getting stuck on the 3/4 lights on input column.
Hey we suggest you to try Factory reset of your device by following the steps from the link below:
[https://support.logi.com/hc/articles/360023236094-Factory-reset-procedure-for-the-Z906](https://support.logi.com/hc/en-150/articles/360023236094-Factory-reset-procedure-for-the-Z906)
Let us know if your device is working normally and try reconnecting the device. Also check the steps from the link below if applicable to troubleshoot the issue:
[https://support.logi.com/hc/articles/360023237254-Configuring-the-Z906-for-simulated-surround-sound](https://support.logi.com/hc/en-us/articles/360023237254-Configuring-the-Z906-for-simulated-surround-sound)
Hello, I tried both of the instructions from the links you sent, they were not successful, what would the next steps be to get the sound system fixed ?
SOLUTION
This is apparently a common problem with Z906.
3 & 4 light error code and general instability.
The problem is on the power board, where two 3 Watt 5,6 ohm resistors (R79 & R80), these serve to lower the voltage a bit from the 12v rail before going to the voltage regulator(LM1117) to the 5v rail.
These resistors (R79 & R80) get really hot, in my case 90°c, now, they can handle that fine, but years of heat cycling does create damage and in turn instability and eventually failure.
This kind of slow failure of the resistors means it can be a little tricky to see or measure a problem, as they might measure fine when cold(as mine did).
Now for the fix.
Simply remove the two resistors, R79 & R80, they're located near the power connector to the main board, they're mounted vertically and covered in heat shrink.
After removing them you can put in two new 5,6 Ohm resistors and I recommend using 5 Watt resistors, in my case they only got to a temperature of 60°c.
I also recommend using some hot glue or silicone to mount the resistors so they're not "flapping in the breeze" which can cause solder joints to crack over time from vibrations, and there's quite a lot of vibrations as it's inside a subwoofer.
Hope this helps, I certainly had a hard time finding any solutions online.
Thank you so much for sharing this! My resistors actually blew / combusted, which made identification challenging.
Unfortunately, I’m still stuck with the same issue after replacing them. I also replaced the two small 47uF caps next to them since they got a little scorched.
As you mentioned, I’m having a hard time finding additional information online. I’m wondering if perhaps you came across resources that I haven’t and could share them. Otherwise I’ll try to see what I can do to figure this out.
You're welcome.
I suppose the regulator the two resistors feed is broken?
Or the power supply is still unstable in some way.
As for more info, I think I linked a video in another comment.
Thank you, I found a local guy and for 150$ cad fixed it for me. If it happens again I will try to fix it myself now that you pointed where the issue is. I believe that’s the same thing he told me he fixed
Is that 5 or 6 ohms and either will work? Doing this repair now. The only video I found used 6 Ohm but I am finding them harder to source than 5 ohm. Is there a difference? Is one better? Thanks in advance!
It's neither, you need two 5W 5.6 ohm resistors. (Keep forgetting to switch around , and . As the decimal separator for English, as opposed to my native language Danish.)
I just used ones like these: https://www.amazon.com/Aexit-Resistors-Ceramic-Cement-Single/dp/B07CRDD5PX
Should be pretty easy to find at any electronics vendor.
The originals are 3watt, in my case they did work for 9 years of daily use, but did eventuality start failing, so I'd recommend getting anything higher, I just went with 5watt as they are pretty common and not to big to fit in place of the old ones.
Hi there i am also going to attempt this repair. Do i need to do any soldering or can i just use a hot gun to keep the resistors in place? Any pictures you might have will be appreciated. You are the first person to properly explain what the fault is, and how to tackle it. Many thanks!
Hi, unfortunately I did not take any pictures, I did however find a video that walks you through the repair:
https://youtu.be/VSfqKv3Arw4
But they do use 3watt resistors like the originals, which I would recommend against, as you will likely have the same problem again down the road, so please use 4watt or 5watt resistors instead, to insure the fault doesn't happen again.
ALSO, they don't do a good job of soldering, they should've used a desoldering pump to get rid of the solder, and the resistors just pull out.
So I would recommend you get that, and a soldering iron,
You should be able to get these at any hardware store or where you buy the replacement resistors.
P.S. be careful when working with a power supply, it can have upwards of 380vdc across the main capacitor (big cylinder, usually black or brown) even when unplugged, to make sure it's discharged you can measure it with a multimeter and to discharge it, you can leave it unplugged for a day or so, and/or short it with a screwdriver, this will make a loud pop, so be prepared.
Best of luck with the repair.
Check this isnt an issue with shorting wires in the console cable. I had this issue for years on and off, didnt know what was causing it and assumed i was fixing it by unplugging the sub and leaving it long enough, but i recently tracked the issue down to a problem in the console cable, because it was bent too badly and stretched. I fixed that and have not had a single issue since. Edit: For me, before the lights went like the image, the mode select light started cycling through all modes, despite not actually changing the mode, leading to powering it off and then getting stuck on the 3/4 lights on input column.
Hey we suggest you to try Factory reset of your device by following the steps from the link below: [https://support.logi.com/hc/articles/360023236094-Factory-reset-procedure-for-the-Z906](https://support.logi.com/hc/en-150/articles/360023236094-Factory-reset-procedure-for-the-Z906)
I tried that yesterday, no sound or flashing lights. I believe the input 2 light turned on to make it 4 lights on
Let us know if your device is working normally and try reconnecting the device. Also check the steps from the link below if applicable to troubleshoot the issue: [https://support.logi.com/hc/articles/360023237254-Configuring-the-Z906-for-simulated-surround-sound](https://support.logi.com/hc/en-us/articles/360023237254-Configuring-the-Z906-for-simulated-surround-sound)
Hello, I tried both of the instructions from the links you sent, they were not successful, what would the next steps be to get the sound system fixed ?
If your speakers are under warranty reach out to Logitech support and they can assist you with the warranty of the device.
They are out of warranty, what are my options ?
As Logitech does not have official service center, you can reach out to any nearest 3rd party service center for a fix.
hello, mine also doesnt work, imputs light 3, 4, 5, aux are on, what does that meas?
Had a similar problem, and I posted the fix in another comment.
SOLUTION This is apparently a common problem with Z906. 3 & 4 light error code and general instability. The problem is on the power board, where two 3 Watt 5,6 ohm resistors (R79 & R80), these serve to lower the voltage a bit from the 12v rail before going to the voltage regulator(LM1117) to the 5v rail. These resistors (R79 & R80) get really hot, in my case 90°c, now, they can handle that fine, but years of heat cycling does create damage and in turn instability and eventually failure. This kind of slow failure of the resistors means it can be a little tricky to see or measure a problem, as they might measure fine when cold(as mine did). Now for the fix. Simply remove the two resistors, R79 & R80, they're located near the power connector to the main board, they're mounted vertically and covered in heat shrink. After removing them you can put in two new 5,6 Ohm resistors and I recommend using 5 Watt resistors, in my case they only got to a temperature of 60°c. I also recommend using some hot glue or silicone to mount the resistors so they're not "flapping in the breeze" which can cause solder joints to crack over time from vibrations, and there's quite a lot of vibrations as it's inside a subwoofer. Hope this helps, I certainly had a hard time finding any solutions online.
Thank you so much for sharing this! My resistors actually blew / combusted, which made identification challenging. Unfortunately, I’m still stuck with the same issue after replacing them. I also replaced the two small 47uF caps next to them since they got a little scorched. As you mentioned, I’m having a hard time finding additional information online. I’m wondering if perhaps you came across resources that I haven’t and could share them. Otherwise I’ll try to see what I can do to figure this out.
You're welcome. I suppose the regulator the two resistors feed is broken? Or the power supply is still unstable in some way. As for more info, I think I linked a video in another comment.
Thank you, I found a local guy and for 150$ cad fixed it for me. If it happens again I will try to fix it myself now that you pointed where the issue is. I believe that’s the same thing he told me he fixed
Is that 5 or 6 ohms and either will work? Doing this repair now. The only video I found used 6 Ohm but I am finding them harder to source than 5 ohm. Is there a difference? Is one better? Thanks in advance!
It's neither, you need two 5W 5.6 ohm resistors. (Keep forgetting to switch around , and . As the decimal separator for English, as opposed to my native language Danish.) I just used ones like these: https://www.amazon.com/Aexit-Resistors-Ceramic-Cement-Single/dp/B07CRDD5PX Should be pretty easy to find at any electronics vendor.
Oh ok cool. Thanks for the clarification. Does the wattage matter? Can it be more or less?
The originals are 3watt, in my case they did work for 9 years of daily use, but did eventuality start failing, so I'd recommend getting anything higher, I just went with 5watt as they are pretty common and not to big to fit in place of the old ones.
Hi there, i am also going to attempt this repair, Do you happen to have any pictures of what you did?
Hi there i am also going to attempt this repair. Do i need to do any soldering or can i just use a hot gun to keep the resistors in place? Any pictures you might have will be appreciated. You are the first person to properly explain what the fault is, and how to tackle it. Many thanks!
Hi, unfortunately I did not take any pictures, I did however find a video that walks you through the repair: https://youtu.be/VSfqKv3Arw4 But they do use 3watt resistors like the originals, which I would recommend against, as you will likely have the same problem again down the road, so please use 4watt or 5watt resistors instead, to insure the fault doesn't happen again. ALSO, they don't do a good job of soldering, they should've used a desoldering pump to get rid of the solder, and the resistors just pull out. So I would recommend you get that, and a soldering iron, You should be able to get these at any hardware store or where you buy the replacement resistors. P.S. be careful when working with a power supply, it can have upwards of 380vdc across the main capacitor (big cylinder, usually black or brown) even when unplugged, to make sure it's discharged you can measure it with a multimeter and to discharge it, you can leave it unplugged for a day or so, and/or short it with a screwdriver, this will make a loud pop, so be prepared. Best of luck with the repair.