Help Required - Repairing a Logitech Z906 Speaker

[Skimask]

Who did the soldering?

[Rerouter]

Looks like only R25 is vaporised, R24 looks to be shorted to his neighbor with a small piece of wire. which based on the numbering leads me to think caused R25 to blow.

For a shot in the dark, i would imagine R25 could be a "131" from his neighbours, meaning 130 ohms,

But definatly get some desolder braid and clean up those areas before you reapply power.

[TheHiFi]

R44, R37, R25, R21, R22 these resistors are connected in parallel (as far as i can see), one end of resistors is connected to mains capacitor negative terminal and the other end is connected to two mosfets(fqpf9n90ct) source legs. (sorry for bad english)

[Zeth89]

Hi everyone! im new and im here looking for help with my z906 psu, i have a missing capacitor, it blew and i dont know it value, i don't have a spare part so i can't messure it, it will be awesome if someone of you could help me try to repair my z906, as I can't find a psu replacement either you guys are my only hope, the capacitor missing is the "C45" in this picture wich i find on this forum, ty all for your help and sorry for my crappy english
i leave my email here if needed
Zeth89@gmail.com.
Pls note that the picture i am using is not from my z906, it is a picture i took from this topic, my specific problem is the missing C45, (black square)  ty again!

[Rerouter]

based on the size i would imagine 1-12uF 50V XR5 ceramic capacitor, would really need an image of what the other side of "TP32" has on it to be certain.

[Zeth89]

Hi Rerouter and ty for your help, i took a couple of pictures of what is on the other side of tp32, and it seems to me that is a couple of 3.3k resistors

[Zeth89]

  :help:

[Rerouter]

The location of the fault doesnt seem like it will be the main cause of your issue, that area seems to be a number of high wattage resistors,

The capacitor while still being my old assumption is a symptom

I would measure the resistance of all of those resistors on the top side in that section, i would think 1 has gone high resistance and applied too much voltage to the capacitor.

[Shock]

Check for dry joints as well.

[Zeth89]

ty for your replies, I'm thinking humidity did this, since it was a stored working unit, it was stored for at least 6 monts, then i sold my main 5.1 hometheater, so i was going to use this z906 to replace it, but when i was going to use it, it blew, I opened it and it has alot of humidity on it, i cleaned it with thinner but i think it wont turn on without that capacitor (c45) that blew, i wanna replace that c45 and see if i can make it work, but i dont know what is the value of that capacitor, as i dont have a spare psu to mesure it, what you think i can do? can it be the 1-12 uf ceramic 50v capacitor as someone told me? but wich one? i wanna give it a try. ty in advance

[Rerouter]

Let's say 4.7uf,

[Zeth89]

Let's say 4.7uf,

Do you think it wouldnt have big impact if it isnt the exact same value on that cap? in case that's the reason it is not wonking.
also, i can see another capacitor that looks pretty similar en the board, the C60 it looks like it can be the same value, do you think i can take it off the board to know its value? ty in advance

[Rerouter]

certainly,

Where it is in the circuit, atleast to me looks to only be a noise filtering cap (High frequency noise, not a normal smoothing cap),

Still i will stress, i do not think this capacitor is the main fault, i believe it is only a symptom of another fault. Did you check out those resistor values? the way that capacitor fails, atleast to me looks like it saw a gross overload of voltage.

[ciine]

I want to make another power suply system for the Z906.
Please help me with:
-level output source before and after starting
-diagrama signals for TEMP3, TEMP RET, nPWR_OFF, PSYNC1 AND PSYNC2
because I do not have physical , power source
Thank you

[Rerouter]

your going to need to give a bit more info,

So your missing the AC power board from inside the unit?

[ciine]

Today I started with another source Z906 system,  source purchased from lcd-tv, but I want to know from you, who own a Logitech Z906 ok ,that provides accurate voltage to pin the original source HV_ pin power
What value is ? 50 , 60 , 70 v???
look the picture

[ciine]

your going to need to give a bit more info,

So your missing the AC power board from inside the unit?

Yes, I`m not have the main power

[Rerouter]

I cannot read the chips next to it, however i would strongly guess HV connects to one of the pins on those amplifier IC's, if so, then look at there datasheet to find the maximum rated voltage and go a bit lower.

[ciine]

I know the chip is tas5162 PVDD voltage is about 70v (max) normaly is 50v
http://www.ti.com/lit/ds/symlink/tas5162.pdf
 I want to know exactly what PVDD voltage feed company logitech
Now powered PVDD with 24 V and works ok, but with limited power

[ciine]

I resolved, I rebuilt a Chinese source for 200W at full power 400w
with the following voltages:
-5V 1A
12V 1A
-40v 10A
It works perfectly

[ciine]

more details

[gnanasekar]

I faced problem in primary voltage section only resistors burned and at the same output section resistor also, if some help to find the values of the following resistors.
R5, R95, R119, R12, R8, primary section Voltage.
R79, R80 secondary section Voltage.


please, post the values for the following values.

[w1r3d]

Need help recognising R5 and R8 resistors too. Them are burnt. I think them are 3K3 5 W resistors (the rest of resistors around are from this value) but not sure. Please, if anyone has schematics or these resistors working the help will be very helpful.

Thanks in advance

[TheHiFi]

I measured these resistors on my z906 board and you are correct they are 3.3K

[Zeth89]

Today I started with another source Z906 system,  source purchased from lcd-tv, but I want to know from you, who own a Logitech Z906 ok ,that provides accurate voltage to pin the original source HV_ pin power
What value is ? 50 , 60 , 70 v???
look the picture

I tested and +hv is 46v

hi all, today i tested the internal psu of my z906, and i can read all the 5v, 12v, and 46v from +hv
but my z906 is not powering on, the other cable that comes from the psu to the main board i can see theres a cable labeled "3.3v keep alive" and i can't read any voltage from that, may be that the reason is not powering on? o do the main board still power on with all that 5v/12v/and  46v from the other connector? sorry for my english, hope you can understand me and help me as well, ty!