My Logitech Z-2300 keeps shutting off - help!

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I hope I don't sound like a total n00b but I found this site while doing a search on my Logitech Z-2300 and I hope you all can help me.

I bought my Logitech used off Craigslist about a month ago for $40 and the only problem with it is (supposedly) that the output jack for the satellite speakers comes loose "every once and a while".

Since I have bought it, I will be listening to MP3's (with my phone hooked up) and then, suddenly, the sound stops. When I go over to inspect the problem, I see that the power-indicator light has gone out. The Logitech is plugged into a power strip and, after testing, all the outlets work. Then, a few hours later, the stereo will work again :confused:

Important note: The first time this happened, and I tried plugging the amp back in, a loud humming sound came out of all the speakers (but the amp was technically off). I unplugged it and plugged it in again and, after a few times, the sound disappeared.

My guess is that it could be shutting down automatically because it is overheating. If this is correct (or not) what should I do? I have plenty of experience repairing and soldering guitar stuff so I don't want to throw this amp out.

Also, I can take it apart and post any pictures that would be helpful - just ask :)
 
I had issues VERY similar to this on a small speaker system of my mother.

After a very long struggle i tested the toroidal transformer. IT tested fine open circuit. But as soon as i put a load on it , the secondary voltage dropped FAR too much for VA.

MY bet is that the transformer is bust OR at least is fine when it's cold but has internal shorts when it gets warmer.
 
why bet on what is wrong with your amp/speaker system??????. unless you can get good odds lol
i have also seen the same fault with transformers.
i have also found the ic can overheat
I have also found bad joints / dry joints.

All caused the same main symptom shutting down.
 
I've seen a shorted transformer in a Logitech system myself - it was a Z-5300. Since there was no way of opening the enclosure, it had to be smashed apart and rebuilt from scratch after the transformer was replaced. Which in retrospect was good for the subwoofer because the speaker had already begun to tear itself apart, the spider got detached from the cone on one side. I glued the spider back on and did a 4th order bandpass instead of the series tuned 6th order it had. And it ended up sounding quite good.

I sure hope the 2300 is easier to take apart.
 
Last edited:
Alright everybody - I got the backplate off today! The only problem is that the wires to the speaker (which are red and black) go behind a panel so I can barely move the backplate.

Also, there are two thick yellow, twisted around each other that go behind the panel as well. I can't see the transformer in the cavity - do you guys think that's what the yellow wires go to?

I tried taking off the front panel but it seems pretty solid.

So the question of the hour is... Do I access the electronics cavity by:

Breaking off the faceplate, then unscrewing the speaker?
OR
Cutting the wires from behind?

I think the best way is to take off the faceplate - what do you guys think?
 
Don't worry - never mind guys :eek:

I just found a video on Youtube that shows how to take the grill off - I'll probably do this tomorrow evening.

Just for the hell of it - I may replace the sub :D

After that I'll try taking the speaker out - how can I test the tranny to see if it's overheating?
 
Last edited:
All right everybody - I finally found some time to open up this beast and I took pics of what I found. Without further ado...


Here's the front with the grill off (and that doesn't look like a speaker cone to me)
Grill-off.gif



The front with the grill off (and, yes, that's the back of the speaker)
woofer-and-tranny.gif



Here's the back of the front piece that came off
back-of-faceplate.gif



Magnet of the actual speaker (I feel deceived - 10 inches my ***)
Woofermagnet.gif



Front of the actual speaker (I still feel deceived)
woofer-front.gif



Tranny
...the top reads:
CEFW5730-00-1
I/P 120 VAC 60Hz
O/P 14.5 VDC 1.6A
04130
tranny.gif



Top of the chassis
Chassis-top.gif



I really hope this unit didn't cost a lot when it was new because the tranny is not torroidal and the speaker looks like junk. Is it common for the speaker orientation to be done this way (backwards)?

At first I was going to relocate/rearrange everything so it would be easier to feel if something became overheated. When I took everything out, I realized that EVERYTHING (including a lot of stuff on and around the chassis) was covered in glue. Because of this, I have decided that the only thing worth doing is replacing the tranny. This is because it is the only thing I would be able to replace - anything else would be impossible to remove because of the glue.

How do I find the correct tranny replacement? Can I use any one that has an output voltage of 14.5 volts and 1.6 amps?
 
The red and black wires carry the load from my wall and the yellow wires carry the smaller current to the chassis. How do I know which yellow wire to touch the negative point of the multimeter to, and vice-versa?

I understand what you want me to do but I've never tested a transformer before - I just want to make sure I don't get zapped :)

Thanks everyone in advance for all the help so far - I can't wait to figure this stuff out :D
 
switch your multimeter to AC voltage. then it does not matter which way round you connect yellow wires to multimeter.

Do not touch the red and black side. No need to measure there. just measure the yellow secondary voltage.

Thanks for the advice! We're snowed in here in Kansas so hopefully I'll be able to get to that today.



are you sure that this is z-2300? Thanks
I feel like an idiot - it's actually a Z-3... I guess I really got taken on this deal. Oh well :Pumpkin:
 
switch your multimeter to AC voltage. then it does not matter which way round you connect yellow wires to multimeter.

Do not touch the red and black side. No need to measure there. just measure the yellow secondary voltage.


Thanks SO much for the advice. Also, luckily, I found a lot of YouTube videos that helped too.

I've had a break from classes and have been able to screw around with my multimeter.

OT but an 18 volt adapter (straight from an eBay member in China) gave me crazy readings. I swear it said about 240 volts but that can't be right. Also, the numbers kept jumping around. Why this is?

FINALLY :eek: here's what I found:
-The outlet, into which I plugged the trannie, puts out about 124 volts. I believe these are "primary volts".

-The trannie, plugged into the wall put out a consistent 14.1 volts. I believe these are "secondary volts".

-When testing the primary wires (the black and red ones) coming out of the tranny, I got a resistance of 12.1 ohms.

-There is continuity within the transformer.

-I tested everywhere on the pcb and found no breaks in continuity.

-Further inspection of the pcb showed tons of epoxy but no signs of damaged capacitors.

What shall I do now?

Thanks again for all the help guys! :D
 
What a load of junk. It probably doesnt even do 10 watts RMS.
If the transformer is OK, it is probably the power amp chip shutting down for some reason. Using that thin metal enclosure as the heatsink, that's most likely why.

Actually, I think it does AT LEAST 25 watts lol

I was wondering why there was a chip screwed on to the chassis - must be for heat dissipation just like you said. I just opened a guitar amp I have and it has the same thing.

So...where do I go from here to figure out what to do? Shall I just wire everything back up and see if it works? If I leave the chassis outside the enclosure, I will be able to feel if it is overheating if everything shuts down (don't worry - I'll unplug it first :t_ache:)
 
As an off-topic, if you block the small port inside (I just stuffed it with old socks), you convert the enclosure from series tuned 6th order (a very one-note design, very critical of port/PR tuning) to a 4th order band pass.
The latter sounded much better to me.

Back to the electronics...
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.