[ramachandra]

Nice! I had never seen the earliest version inside. I only expected to find RCAs on the place of the spring clips, but this PCB is something else and hold two extra unoccupied spaces for OpAmps, resistors are installed there, probably for nothing.
 
Judging about the arrangement, the green films and the single ceramic disk on the bottom is belong to the Sub, so that area need the upgrade. The 3 pieces on top is part of the 5 remaining channels. They have to go + belonging components. If i have this board I make good photos first for safety, then I stick to the back the 5 pcs 0.47uF cap, connect the pins to the D-Sub and desolder the necessary wires from the PCB, and connect them directly to the other pins of the 5 film cap.
 
I suggest to not bother with the OpAmps on top first, just see how the mod is doing, then get rid of them. (They may have an audible effect on the sound as long as they stay connected)

 

[rxracer]

First of all, wow.... you seriously know your stuff about the z-5500.  Hence the reason i'd like to ask for your opinion regarding the issue with mine.
 
I re-wired my system yesterday and noticed the left rear was popping, crackling, and had no sound.  Then after about a minute or so I hear a mild 'whoop' sound, like when you power of some speaker systems. Then all sound stopped, and the control pod LCD showed 2 rows of black bars.  Like the volume at full bars, but 2 rows.  The entire space of the LCD screen.
 
So I fiddled around a bit.  And here is what I've observed.
 
1. Plugged different speakers in the left rear channel.  Popping remained.  Conclusion.  Issue is with the left rear output, not the speaker.
2. Turned the system on without sending a signal through.  Control pod worked fine. Black bars never appeared.
3  Plugged just one (center) speaker in and sound played fine for over 30 minutes.  After that got kinda tired of watching a show with just one speaker, but considering how quickly the sound shut off with all the speakers attached I'm confident it would have worked indefinitely.  To be thorough I also did this test with the speaker in all the outputs except for the left rear.  No issues.
4. Added the 2 front speakers and the problem came back.  Sound shut off after same amount of time.
 
So I kinda have 2 problems.  The crackling/no sound from the left rear, and the system hanging after a minute or 2.  But I can't help but think one is causing the other.  Since neither issue was there before, and both appeared at exactly the same time. 
 
Does the fact that it runs fine with the center speaker, but shuts down when you start adding more seem like there is some sort of overload deal going on.  There is obviously at least one faulty component, but I'm no electronics expert.  I do know my way around a soldering iron, but I kinda need somewhere to start.  I ran quite a few searches and someone suggested the pre-amp.  Does make sense as the speaker outputs are connected to it (I have opened the sub and identified the main components).
 
I can't help thinking the biggest clue, if I knew exactly what I was doing, is that I do actually get sound for a minute or 2 before it stops.  I have read a number of posts from other people with the 'black bars' issue, and none of them get any sound at all.  They get the black bars the moment it's turned on.
 
Sorry for the long post.  Just wanted to give you as much info as possible.  While I could forget it and go buy a new sound system, I have no doubt that when I find out what's wrong it will be inexpensive. Maybe time consuming, but I'm fine with that love fixing things myself   Plus, I'm really keen on doing a bunch of your cool mods.

 

[rxracer]

double post

 

[rxracer]

Ok... so kinda scratch most of the issues above.  After opening the sub and gently looking around with a torch for anything fried the system has now decided to become basically inoperable.  Now, it no longer works with one speaker, and does the black bar thing with or without a signal or speakers attached after a minute or 2.  In a way it might be easier to diagnose.  Now there is just one issue. 
 
Is there an overload kill switch other than the fuse?  Cos I noticed that just a few seconds before the pod screen does it's thing and power to the speakers cuts out, the slight hum from the sub gets louder, before ending in that 'whoop' sound.  Sort of like it's leading up to the cut out.
 
Also, are some of the smaller capacitors and microchips supposed to get BURNING hot?  I actually saw a little smoke coming from one of the capacitors for a second.  And the whole board generally has a faint burnt plastic smell.
 
Here's the sound the malfunctioning speaker channel creates -
 

 

[Bojamijams]

Sorry to hear that RXRacer.. I was very excited to try this mod out but your stories remind me that I'm not good enough to play with this stuff yet.  

 

[ramachandra]

A bit of sniffing on the board and the location of smoke you had seen is help to pinpoint the place worth to investigate. Cracks, oily liquids matters. Because this problem started after the new wires, the logical guess is a broken TDA7294 near the thick white wire.
If you do not mind a maybe wain experiment, unscrew it keep bending it until all the pins break make sure the remaining pins are not causing short circuit and screw back the rest, then turn the system on. If it stay stable you have found the faulty part. The remaining pins are easy job to remove with the iron and solder pump. A new TDA7294 is cheap. If it worked, get rid of the 22uF electrolytic cap near the wire too when you install the new amplifier.
 
There is a list of other things to try we have already mentioned on the thread, like checking voltages under load, try new OpAmps, use a pod replacement cable, recap, or do the third mod just to narrow down the possibilities.

 

[rxracer]

Thanks heaps for the advice ramachandra.  Yeah I traced the left-rear to to the white wire, was thinking something connected to that would be the issue.
 
I've always wanted to expand my limited knowledge of electronics, and despite paying just $60 forthis unit, I hate giving up.  This has inspired me to get off my ass and start studying.  I'm actually picking up a second faulty unit next week for free, so it will make it much easier to diagnose issues, and/or use it for parts swaps since all I know about the other unit is it 'won't power on'.  Could just be a simple fault in the power plug area.  Or a bad control pod.  I'll also be reading this entire thread as it seems to have some great info. 
 
Again, thanks.

 

[scratje]

Hi ya all

 
It's bin a while since my last visit here and i want to share an update with you about recapping the main capacitors.
Because the leads are thicker than the originals i drilled bigger holes in the through hole connections.
Now. after several months one of my Z5500's started with a loud hum and rattling sound when switched on one morning and i knew right away that this must be from one or more main capacitors.
I desolderd them and found out that one of the through hole connections between the front and back of the circuit board had been disconnected (broken).
Because of the drilling the through hole connection must have become very thin and now, after months of playing music  and vibrating, the connection broke.
I want to advise you all to prevent this by using copper rivets in advance, which you have to fasten tight and solder them to the existing through hole pads.
After that (the solder will flow into the hole of the rivet) you can drill them clean again and then resolder the capacitors.
 
I made my own brass tools to fasten the rivets with a hammer but you can also buy them on the web.
Her a pic of the rivets i used (1.0 mm through hole x 1.4mm) and the brass tools.
 

 
Intill now i am very pleased with my two modded Z5500's one of which plays in a local pub for over half a year now

 
 
 
Greetings, scrat

 

 

[Axell2Axell]

   
I will heat up the old soldering iron tonight .
 
As a first step I will confirm Sub-D pinout vs wiring color vs WA# connection by desoldering wire by wire and use the multimeter to confirm. I didn't do anything with the new POD, as I didnt wanted to tamper with the "working" POD yet
Regarding converting the old one to the new one. The old one is "broken" and I am in no position (toolwise and experience) to desolder the CS42526-CQZ and resolder a fresh on one it (still got 2 spares lying around.... _somewhere

). At least I can use the old one as spare bin for SMD components if I spot a difference between the two (and offcourse document it for future reference)
I wished I had a scope / logic analyzer (and the know how how to use them haha) here so I could at least verify if and what changes when I start tampering with the POD.
 
After verification of pinout / colors / WA# I think I will first start with opening up the bridges (yellow wire, SMD component).
 
Are there any other things I could do with just my simple multimeter ?

 
 
Hi Z5500owner!
 
I have exactly the same problem with my system. I have one of the first z 5500 series that came out. It have served me well over the years, and I like it very much. But now the pod has completly crashed, and I have bougth myself a new one, but it will only play stereo and stereo x2, nothing else and I don't like that. So now I am humbly asking if you have found a solution for this problem and if so, would you be so kind and help me with what to do!

 

[z5500 digital]

Ramachandra
Thanks for the detailed information and recommendations.
 
I own a z5500 (pid: R649) ~ 9 years.
Few mid and high frequencies.
Previously used a standard cable.
Heard the faint squeak if to lean an ear.
When you increase the volume you could hear the squeak better.
Disable all devices in the house didn't help.
Changing the source didn't help.
Improvised shielding did not help.
All satellites constantly squeaked.
 
In the summer I decided to upgrade the audio system.
Updated the surge protector are now "Monster MP HDP 450".
Replace the standard analog cable to optical cable "Onetech DAT6003".
Updated standard speaker wire, now Supra Sky 1.6 mm.
Partly increased audible frequencies.
The difference is very noticeable.
If to lean an ear, the squeak from the satellites remained, but the volume control now does not influence it.
Standard analog cable was probably not the best quality )
 
I deduce a sound through a built-in soundcard:
asus.com/Motherboards/H87PRO
As operating system I use Ubuntu and Linux Mint.
For better control of the channels, used the manual:
help.ubuntu.com/community/DigitalAC-3Pulseaudio
I can now manage not only stereo, but also all channels.
The display control unit now says "Digital".
 
I never dealt with soldering electronics.
But a simple soldering iron I had.
And I even know how to handle it )
 
Now I plan to purchase a external sound card or a modification of the standard system components.
What better to do in the first place ?
Does it make sense to buy a sound card for optical connection ?
Please tell me.
 
Excuse my French, I'm from Moscow )

 

[ramachandra]

"Does it make sense to buy a sound card for optical connection ?" Probably yes, but certainly better trough analog connection after modification.
"What better to do in the first place ?" "I never dealt with soldering electronics." Then you should start on a sound card, definitely not on your Z5500. Some beginners are good from the start, some experienced end up with disaster. Anything possible.
"All satellites constantly squeaked." I do not know this one. If your system is the 9 years old probably from the first series, they had more tendency to be sensitive to external noises caused by other equipment, or Wi-Fi, PSU of your PC, too long extension lead, something on the street or in the neighborhood. Or can be other things we had mentioned on the thread, like loose or aging main filter capacitors not properly arranged wiring etc. 

 

[laciv]

HI, very nice job, thanks for effort. Could you please post schematics of Subwoofer board, mute board and standtby board. Thank you in advance.

 

[ramachandra]

Hello, We do not have any from Logitech, but jayjayuk took the challenge and drawn schematics from the system, u can find them on the 10. page.

 

[laciv]

hello, thanks for quick reply. I have seen the schematics already, just now I learned how to download pictures in original resolution.

 

[milspeccqb]

Thank you guys for all the work you've put into this. I have a Pre 636 Z5500. About three years ago it failed while being used as my home theater system. The Pod still lights up and can be used but I get no sound from any speakers. I looked for solutions at the time but most said the control pod goes bad when you stop hearing sound. I recently picked up one of the control pod replacement devices but still did not hear anything from it.
 
http://www.ebay.com/itm/320835307449
 
So now I assume something has gone bad in the Sub. I pulled the board out and took a look. I know the amps can go bad and I know this isn't really a repair forum but do you guys have any things I can look for, some basic diagnostics?
 
Here are all the photos I took.
 
http://i.imgur.com/GrsZWND.jpg
http://i.imgur.com/NB6skPI.jpg
http://i.imgur.com/4bj5K1W.jpg
http://i.imgur.com/r7kbPxk.jpg
http://i.imgur.com/G3UXc1S.jpg
http://i.imgur.com/A3FIME2.jpg
http://i.imgur.com/QqQ9OEo.jpg
 
When I took it off, first time it had ever been removed, I noticed that the red wire coming from the amp to the sub had got caught inbetween the metal plate and the box and unfortunately it looks like the was right over a screw hole. 
 
http://i.imgur.com/CBeJBMi.jpg
 
I don't know if that contributed to whatever failed or not. Any suggestions or help would be much appreciated.