Hi lex..i do wonder where do u repair subs..dont have any idea where to repair

Just monitor the base of the transistor. If there is voltage at the base (at least 0.55V or higher) when the relay goes off (clicked for the second time), then could be the relay. Otherwise monitor the +9V rail which powers the relay (for any relatively large voltage dips when the relay is switched on) . If both turns out OK then the fault could be from the control section (mostly MCU controlled, which is much more difficult to diagnose).

For your information, I do repair speakers and subwoofers. Just PM me for details if interested...

Hi Lex !
I change the diodes D6,D7 now it is ok. Thank you very much !!!

Those are diacs actually. Never thought those on the main power section (for power amplifiers) could affect the standby functions. I guess the MCU also monitors the main power section as well. Will take note of that...

Yes. I made a mistake it is diacs. Replace 2xBR100/03 with 2xDB3.

Hi Lex !
ASUS sound cards is more better like Creative ?
ASUS Xonar D2X, 7.1 - is a good sound card ?
It is safe to use hot silicon on the capacitors?
Thanks.


Attached thumbnail(s)

Usually those ASUS cards are rated better than Creative ones. The only Creative soundcard that is considered fine (can be recommended) is the Titanium HD. Others like those from ESI Audio (which now owns AudioTrak) and Echo Audio are also recommended as they are considered HiFi and studio quality. You can also use an external DAC, either using SPDIF (optical, coaxial) or USB connection. You can try inquiring here as well: Special Interest -> Home Entertainment -> Audiophiles -> Headphone Amplifier and DAC Recommendation, portables, desktops, amps, dac, lai (Headphones)...

Can be used for ceramics, but not recommended for the "lytics" (short for electrolytic capacitors). You do not want to boil the electrolytes inside those capacitors.

This post has been edited by lex: Oct 7 2013, 03:34 PM

Lex,
Got one set of 750's going thanks to your very detailed walkthrough but have come up against a problem with another. No Power and no obvious problems on the board. When I turn it on, I get nothing, no light blink or anything that might suggest power to the box. I tried the lead, the fuse, and still nothing. I know next to nothing about what is what or how to test things, I only know if something doesn't look right replace it. Any clues what I should be doing here to diagnose it?
Cheers
Rod

The usual troubleshooting procedures, for example check for failed components and check whether there is output voltage on the secondary standby side (if none then check voltage at transformer, then if none then check voltage at primary standby side, etc... etc...)

This post has been edited by lex: Oct 17 2013, 02:38 PM

Very cool finding this thread.

Lex, you give a spec list of the capacitors to get however I didn't see a brand you recommend. Could you steer me in the direction of a brand that you think is a good quality?

Also, what type of Ceramic resistors should I get for the orange ones and the diode?

What about the Mosfets? They look kind of funky on the bottom, are they fine and just need a cleanup job or do I need to replace them as well?

Thanks for your time!

UPDATE: and I'm a dolt as I see you listed what type of capacitors you got. Where did you buy them from? I want to make sure if I buy them I get the right ones.

This post has been edited by Kahlid74: Dec 4 2013, 11:39 AM

For capacitors, look for brands like Nichicon, Panasonic (also known as Matsushita), Rubycon, Nippon Chemi-Con (also known as United Chemi-Con, formerly Marcon), and Sanyo (nowadays known as Suncon).

So far had not had to replace any resistors, except for that 0 Ohm link. As for resistors, depends on the original resistor being replaced and should follow the wattage of the original resistor (in other words, the size of the resistor determines the wattage). The diode is pretty much run-of-the-mill 1N4004, which is a very common diode.

That one very much depends on whether you're going to replace them, and/or depends on the fault/problem itself. The "funky" look is mostly leftover excess flux and not degraded glue. If any of those MOSFETs had blown/failed then you will need to replace them.

Try online stores such as RS Components, Farnell/Newark/element14, Mouser and Digikey. They are guranteed to sell original capacitors (and not those Pasar Road counterfeits).

This post has been edited by lex: Dec 4 2013, 01:41 PM

Awesome LEX, thanks so much!

What about this guy, would I need to replace it?

Just change all those 85C capacitors to ones rated for higher temperatures, such as 105C ones (as shown in my guide here). Preferable to use those with high ripple current handling and/or low ESR type, as this speaker uses switching mode power supply...

What about the guy at C52, the ceramic resistor that is chipped away on top?

That is Ceramic capacitor=) btw how can it become like that??lol

That's not a "ceramic resistor", but a ceramic disc capacitor. Just replace with another one, of the same capacitance. Usually should be 100nF or 0.1uF, 50V or higher.

Per your first post I have tracked down all of the capacitors except 2x 47uF 25V, what brand did you use for this? Here is my shopping list: Does it look right?

• - 4x 470uF 200V 105C, high ripple handling type (for inverter and/or ballast operation)
○ This one had two sizes. I chose the fatter/shorter ones. Correct choice?
○ http://www.mouser.com/ProductDetail/Panaso...%2fxKQ%252bI%3d
• - 2x 330uF 100V 105C, low impedance and/or low ESR type (for SMPS operation)
○ http://www.digikey.com/product-search/en?mpart=100ZLJ330M12.5X35&vendor=1189
• - 5x 220uF 35V 105C, low impedance and/or low ESR type (for SMPS operation)
○ I choose cut tape for these, is that right?
○ http://www.digikey.com/product-search/en?mpart=UHE1V221MPD&vendor=493
• - 5x 100uF 35V 105C, low impedance and/or low ESR type (for SMPS operation)
○ I choose cut tape for these, is that right?
○ http://www.digikey.com/product-detail/en/UPS1V101MPD1TD/493-11570-1-ND/4319749
• - 1x 68uF 450V 105C, high ripple handling type (for inverter and/or ballast operation)
○ http://www.digikey.com/product-search/en?mpart=UCS2W680MHD&vendor=493
• - 2x 47uF 25V 105C, low impedance and/or low ESR type (for SMPS operation)
○ ??
• - 1x 0.1uF 50V 105C, high temperature type prefered (such as ceramic) as its very close to the heatsink
○ http://www.digikey.com/product-search/en?mpart=AR205F104K4R&vendor=478

digikey shipping exp if i am not mistaken

exp?

This one is incorrect as its rather wider than the original. The diameter should be 22mm otherwise the capacitors will not fit together. Should be this 22mm diameter version (if using Mouser): Mouser > Passive Components > Capacitors > Aluminum Electrolytic Capacitors > Aluminum Electrolytic Capacitors - Snap In > Panasonic EET-ED2D471BA...

Incorrect one again, as the lead pitch is 3.5mm. Should get the version with 5mm lead pitch. Digikey > Capacitors > Aluminum Capacitors > UHE1V221MPD6...

Look for Nichicon HE series, like this one: Digikey > Capacitors > Aluminum Capacitors > UHE1E470MDD.

expensive...but i am not sure...