Hacking the Logitech Z5500

so my logitech setup got hit by lightning. Any time i turn it on it immediately blows a fuse (yes the slowblow ones). After doing some research I think it might be the toroidal transformer. Does this sound logical? How can I go about testing this? Any other ideas would be appreciated.

Thanks
Jesse


You probably have damaged the power amplifier (TDA7294), which causes a large increase in power and eventually fuse. Pull out the electronics and check them.
 
Getting lost in this thread and cannot find my answer

Hi to all.

I have trawled through this entire (EXTREMELY HELPFUL) thread and have either overlooked, or simply cannot find a direct answer to a common issue.

I know this has been asked 1000 times in various ways, but most seem to be driven by wanting to bypass the POD completely, which could be an option for me, but as I am already going to buy a standalone receiver and better quality components for our family lounge, the Z-5500 will either go in the bin (a VERY expensive waste which will leave a bad taste in my mouth) or I will try to resurrect them and pass them onto my daughter ... a much better option.

My Z-5500's have only ever been used at TV listening levels (Media Center and Cable TV here in the UK) and everything has been working fine for the 1.5 years we have had them, until the Sub stopped working last week.

I have opened the POD up as well as the subwoofer and looked for any obvious loose connections or bad/dry solder joints etc.

The actual driver works (connected it to the Centre out and ran the pink/white noise test) but the sub output wires are dead ... including trying them on a loose 8Ohm driver.

Is it more common that there is a quirky POD or wiring issue, or are one or some of the (preamp or amplifier itself) components known to die for no reason like this.

Does anyone know the simplest way to test the Sub amp or preamp to determine the fault?

I am quite happy with a soldering iron on small components etc and have a decent multimeter, but am not knowledgeable when it comes to identifying faults (without advice that is).

If it were simply a blown transistor or an op-amp and I could identify this, then I would give the repair a go ... if it ended up being a more complicated fault, then I would have to consider the bin or wasting more money on a repair.

Thanks for any help on this.

Steve
 
Hello guys im new to this community and i would like some help i just recently bought z5500 with no control pod and i have a bypass cable how would i connect to a tv or Laptop do i need any program? or steps to get it working with the bass my Laptop is Toshiba Satellite L505
 
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Hi every one, Can anyone assist me with my z-5500 , it kept burning fuses so it was taken to an repair shop where the guys replaced two ics that was faulty TDA 7294. Now it does not burn the fuses instantly but it powers up the pod but now no audio is outputted from any of the speakers. The pod works perfectly because i connected it to a friends system and ot WOrks but the woofer PIDR817 (SPring Clips) refuses to output any audio , all the other ics were checked and seemed to be fine ..have anyone encountered that problem and have a solution ...email me markavelee@hotmail.com thanks
 
z-5500 no audio

Hi,
one more thing i connected headphones to the pod i hear audio from the headphones but non from the unit itself .
Or does anyone have a working sub unit with a PID higher than 700 willing to sell, Im left with a working pod unit and satalite speakers but no subwoofer
 
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There are 2 options. The first is that your control pod does not match the subwoofer electronics revision (check PID). But if before burning fuse set you to work, unfortunately electronics subwoofer is still broken (I have the same problem :( ).
If you connect headphones to the control pod, the music comes directly from the computer (bypassing the subwoofer electronics).
 
Well i dont have a descrete amplifier to bypass the subwoofer, even if i did i wouldnt want to do that but rather try and have the electronics in the woofer repaired, but the pod does match the woofer unit, its the original pod and woofer configuration. I know the problem is with the subwoofer's electronics what im asking is how can it be fixed
 
Thank you Toffmonster! Your help has been truly instrumental. I performed essentially the same mod you made (because my unit is exactly the same) but in a different way. I will summarize below so that anyone else can perhaps follow my procedures as I think it's significantly easier to solder.

From what I have gathered, there are three different varieties of Z-5500's. The RCA version, the early spring-clip version, and the late spring-clip version (PID 636 and greater, including the rolled over numbers made in recent years with PID's 001 - 200). If you have the late spring-clip version, buy a bypass cable on eBay and be done with it. If you have an early spring-clip version such as I do (PID R608), then buy a bypass cable on eBay and be prepared to do some soldering.

I found this post and this post very helpful in understanding what it is you have to do. What I did is solder from the +8V feed to the orange wire (pin 8) followed by a 100 ohm resistor connected to the white wire (pin 7). This basically supplies +8V to the orange wire and +5V to the white wire (+2.5V under load).

I'm hoping there isn't any long term negative effects in supplying +8V to the orange wire; if there are, I'm assuming it will only damage the center channel. I suspect though that the control unit supplied +8V to both leads as that is what it was fed. In any case, this makes the soldering much easier and allows you to make only three solder points on the board, which significantly lowers the risk of damaging any components or the board.

I've attached pictures of my board to make sure whoever is trying this has the exact same board. I have also attached a picture of the board after the modification. I wrapped it in electrical tape and tucked it away after I took the picture. Good luck! :)
 

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Do you have an idea how to get rid of the high-pass filter in the Z-5500 for example, the two rear channels?
I wanted to hook up the speakers full range, but unfortunately the original connection they do not fulfill their role.

You can bypass the three opamps on the left on the preamp board (as on the upper picture) with five wires (the upper one is the rear chan, the middle is the center chan and the bottom one is the front chan). Idealy you will have to remove the three opamp. But these five high pass filter should not be resposible for the final high cut off frequency. You will have to test it to know (maybe one more filter could be in front of each chan power amp tda7294).
 
Hey guys. I acquired another Z-5500 (late spring-clip version). The front-left channel is much quieter than the other channels (about 20dB quieter!). If I turn the other channels way down (through my computer soundcard) I can still achieve high volumes from that front-left channel, but again, the other channels are turned way down.

Any ideas what this could be and how I could fix it? Thanks in advance!
 
Hey guys. I acquired another Z-5500 (late spring-clip version). The front-left channel is much quieter than the other channels (about 20dB quieter!). If I turn the other channels way down (through my computer soundcard) I can still achieve high volumes from that front-left channel, but again, the other channels are turned way down.

Any ideas what this could be and how I could fix it? Thanks in advance!

By me there are three options:
1. Falling out jack, badly inserted, etc.
2. Defective operational amplifier U13
3. Damaged Cirrus Logic in Control Panel
 
A small addition to my previous posts. Took some pictures of my PCB and checked what pins orange and white cables lead to. It appeared the orange cable that turns my center speaker on is pin 8, while the white cable that turns the amps on is pin 7. So it's just like the thread said in the beginning, Pin 7 is On. But in my case Pin 8 isn't Mute but Center On. :)


Looks rough, but it works.

Hi,
Now that my pod has finally died, i have no choice but to follow ur guide cuz i have the same pcb in the sub. i gave the white wire 5v and im getting that buuuuuuu sound. I do not have the ebay bypass cable and the db15 schmatics has wrong number on it you posted. This is where im stuck. ive hook up all speaker to a receiver and i cant get the sub workin. Ive tried different combination on db15 connecter but nothing.

any help will appreciated
 
Thank you Toffmonster! Your help has been truly instrumental. I performed essentially the same mod you made (because my unit is exactly the same) but in a different way. I will summarize below so that anyone else can perhaps follow my procedures as I think it's significantly easier to solder.

From what I have gathered, there are three different varieties of Z-5500's. The RCA version, the early spring-clip version, and the late spring-clip version (PID 636 and greater, including the rolled over numbers made in recent years with PID's 001 - 200). If you have the late spring-clip version, buy a bypass cable on eBay and be done with it. If you have an early spring-clip version such as I do (PID R608), then buy a bypass cable on eBay and be prepared to do some soldering.

I found this post and this post very helpful in understanding what it is you have to do. What I did is solder from the +8V feed to the orange wire (pin 8) followed by a 100 ohm resistor connected to the white wire (pin 7). This basically supplies +8V to the orange wire and +5V to the white wire (+2.5V under load).

I'm hoping there isn't any long term negative effects in supplying +8V to the orange wire; if there are, I'm assuming it will only damage the center channel. I suspect though that the control unit supplied +8V to both leads as that is what it was fed. In any case, this makes the soldering much easier and allows you to make only three solder points on the board, which significantly lowers the risk of damaging any components or the board.

I've attached pictures of my board to make sure whoever is trying this has the exact same board. I have also attached a picture of the board after the modification. I wrapped it in electrical tape and tucked it away after I took the picture. Good luck! :)

How to get "sub in" connection if you dont have ebay bypass cable. ive tried the 6,7,8 to 13 ground but still no sound from the sub. any help would appreciated
 
Hello guys. This thread has been truly inspirational! I'm very thankful that it's even possible to find this much information about hacking the Z5500.

I'm in NO WAY an audio geek. I have almost no knowledge what so ever in this field. I'm an electrician and I also like working with computers, inside and out.

At work someone told me they found a speaker in a house that had been auctioned away, and it was to be thrown out. I looked at it, and it was the subwoofer/amplifier from the Z5500 system, and it looked to good to be trashed.

I took it home, and thought it might be usable, but no. There was no control pod.
Then after some googleing i find you guys!

Now. What to do. My plan was making this into an active subwoofer, that would work together with my Sony 5.1 amp. It's got a preamp phono jack out, for subwoofer connection.
One of you had reverse engineered the pinouts, so it made the job quite easy.

I'm an electrician, so I have testing tools. I started measuring from pins on the connector on the back, to the circuit board inside, and found out where pin 6, 7, 8 and 13 ended up. Then I soldered 4 wires on. I mounted an RCA connector in the back of the subwoofer amp plate, and soldered the 4 wires to ground. The I found out that pin 2, Sub In, was the grey wire in the wire bundle, so I cut that and wired it to the center of the mounted RCA connector.

And it worked! My Sony amp can turn up and down the volume on the subwoofer individually.

Now I'm thinking about modding even more. I'm trying to find out, how I could alter the frequency range. The woofer is playing to much of the sound spectre.(Yes, that probably not how you say it)
 

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pioneer vsx-921-k to logitech z5450 subwoofer

I've seen some great progress on this thread. I was wondering if anyone would be willing to make the cable to connect a Pioneer VSX-921-K sub out (RCA) to the logitech z5450 subwoofer. I have the front Left and Right connected to the receiver now, but I wanted to repurpose the subwoofer. One of the rear wireless speakers died (red flash, has the bad resistor in it..i think), so I'm looking to repurpose parts of the the unit.

I'm willing to PayPal some money once I see that it works.