Logitech Z506 demise and disassembly

Back in varsity I had a set of 2.1 channel Logitech speakers. They were great, simple and provided good sound. Alas one day they stopped working, never found out why, even after taking it apart (one had to saw open the wooden sub box) and getting several friends and family members to analyse it. In any case, I ended up purchasing a Logitech Z506 5.1ch set to replace them.

And they’ve done me well. Until recently. I’ve had them for about 3 years; I would have expected a longer life but I fear the recent spate of load shedding (and related grid instability) might have given them a knock (oddly I think it’s what happened to my last set too).

Anyway, they stopped working unexpectedly, so logically I took them apart. You can see the process below. It’s quite nicely put together, but also not with the intent of it being taken apart again later.

In any case I looked around a bit and saw that what I still believe is a fuse was not letting any current through (marked T3.15A250V). So, lacking a replacement fuse, I shorted the fuse and thought I’d fixed the problem, alas I fear there was another reason why the fuse had gone as I plugged the power back in.

Cue loud bang, my lights going out and enough flames to give me a fright. 10 o’clock at night, I made my way to my tripboard and reset the plugs, unfortunately I had also managed to trip the switch in my landlord’s house. Fortunately they were still awake and didn’t ask too many questions as I asked if I could check their tripboard quickly.

So I’m once again in the market for new speakers (edit, managed to revive them, see below), but for others who might have more luck than me, here are instructions to disassemble.

Unscrew the 10 screws on the backpanel. Unscrew the 4 screws mounting the speaker to the bottom of the box. Pull the speaker out. You will notice bendy wire clips stapled to the case holding cables in place, loosen these as required.

Undo screws on back and bottom of speaker

Undo screws on back and bottom of speaker

If you have small hands you can unplug the speaker, but otherwise rest it on top. The backpanel slides out, but there is a bit of double-sided tape holding it in place at the back under the panel. You can release this by pulling the PC-Board away from the side of the box. You can then pull the backpanel and PCB out. This will let you unplug the two plugs on the power supply.

Plugs to unscrew and mounting points

Plugs to unscrew and mounting points

With the main board out, you can loosen the two screws holding the PSU in place and slide it out.

partsSimple as that, above you can see where the fuse I shorted was, and also a bit of the transformer which I think I burnt out. Oops :(

A bit of searching led me to believe that I could fit a replacement power supply and all would be alright. I had a spare laptop power supply (90W, 19V) lying around, and I wired this up. So far it has been running like that for several months.

It is also possible to buy direct replacement boards, for example here.

111 thoughts on “Logitech Z506 demise and disassembly

  1. My z506 logitech speakers jst died a day ago due to power cuts…..on/off button does not work…..i dont know what to do but i think i hv a solution………i was thinking of bypassing the damaged transformer with input 240v AC /3.7 A with output 12v DC/ 1A adapter to supply the board……..pls help,will I temper the power of the speakers????????????

    • A 12VDC 1A power supply will only give you 12W of power which is far less than what the speakers are capable of.
      The system will probably work with your power supply, but I suggest something with a slightly higher voltage 16V, and at least 2A

      • Hi, I have also had power supply fail on my z506.
        I left it 2 years ! but this week got a plug in 15V DC 2A and it works fine. One question please is which way the bass plugs in as I removed it ages ago and the pcb is not marked well enough!

        • Hey George. The plug for the sub should only be able to plug in one direction. I opened mine up now to check. And the negative terminal is below the positive terminal if the sub box is the right way up and the amp board is mounted.

  2. Hi Gareth.
    May I know the recommended power rating of the laptop psu which use to replace the power supply for the Logitech Z506? My Logitech Z506 power supply just blown when I turn on the power. Heard the “pop” sound after turn on the switch.

    • The one I’m using is rated 90W, but that’s only because it’s what I had lying around.
      Anything over 50W should be OK. The speakers are technically rated to 75W, so if you want to get everything out of them, you’ll need that.

  3. Thanks Gareth, you are a Gentleman and a Scholar, you have saved me a small fortune trying to find a power supply, now to dig up an old laptop supply from my boxes of junk.

  4. Thank you for writing this, I had the exact same problem. Replaced the power supply board with a laptop power brick with an output of 19v 3.42 amps and now it all works again. Thanks again.

  5. Hello,

    Im having the same issue here and tried to claim the warranty (just 11 months old) but
    they refused (sic).. so i’ve decided to DIY repair for this set, now i’ve read the discussions here and could figure out the tools and parts needed.. Im just stuck on how to make it, would u please share some pics-how do u connect those laptop psu to the subwoofer, did u remove the whole psu on z506?

    • There are two wires which go from The psu to the main amp board. You can unplug this from the psu and connect it to your own power supply which is similarly rated.
      You can remove the psu if you wish as it will no longer serve a purpose.

      Why did the store refuse warranty? Try contacting Logitech directly to resolve issue.

      • Thanks, i’ll try!

        I did contact logitech directly and they give me aplenty of instructions, only the local distributors here were ridiculous(i bought this via online).. I’ve send the 506 to them for inspection and validation, so they find the fuse blown..totally! but they told me logitech just refuse the claim, that was 23 months ago..
        Im tired of fighting this, so used the net and search for help..

  6. Dude… You saved my day. Thanks a lot for this awesome post man. My z506’s fuse was blown last night and I was wondering if logitech would provide a replacement. Claiming warranty and getting it replaced is a awful process. Finally found your article and it’s up and running again. Thanks again bro…

  7. I have the same issue an i have a laptop charger thats 12v 8.3amps does any1 knw if itl work ok or cook me haha

  8. Hi Gareth

    Would you consider :
    1. Showing how to remove noise (due to laptop power supply affecting the sound the speakers pickup) .. (My present method is to output the audio to a Bluetooth, so that it does not connect physically to the laptop, but I’d hope there are better methods)

    2. Modding the speakers, so the power on off button, additional volume control are separated from the physical Right speaker (and maybe extended cable, so that the speakers don’t have to be moved and bothered to power or change volume), and maybe making the volume control digital or motor controlled, so that an infrared control can control the power, standby, volume up and down ?

    (Yes a person can just buy a new set of computer speakers, but If someone else was interested in modding this set as mini projects just to learn about those controls, itd kind of be fun to get it correct)

    • Hi Wesley, I unfortunately no longer own my Z506 set.
      1. Try find a better Power Supply, or ensure that the power supply you are using is grounded, and that your laptop’s power supply is grounded too.
      2. All this is achievable, just depends how much work you want to put into it. Good Luck :)

  9. Due to a chaotic move I’ve mixed up the power supply leads, I think I’m right in saying that the Z506 is a direct (UK) mains input (two pin) but it would be nice to have this confirmed before I plug it in !

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