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-   -   EMU 0404 usb 2.0 with a power on problem (http://www.diyaudio.com/forums/equipment-tools/222517-emu-0404-usb-2-0-power-problem.html)

lemon 30th October 2012 12:18 PM

EMU 0404 usb 2.0 with a power on problem
 
1 Attachment(s)
I bought this for parts from ebay.

Like seller told me, it damaged by opposite power polarity or by power polarity bridge, probably.

After power on, nothing is happening!
Because we have not any circuit diagram, I am looking with the continuity of multimeter the paths after power switch.

It is a searching in blind, sure! Maybe the best solution is to find the appropriate flex connector for working with the both parts open, not closed like now.

After that, I found some electronics to have a relation with the power paths. At the attachment photo I have mark some of these.
I have changed 2 of these (by yellow circles) and now lights on the green led (power on led) above headphone level, but no any other led.

1) Any suggestions?
2) Can someone find to me the appropriate code (farnell, mouser) for extra flex connector? I want to work, with both sides open.

lemon 14th January 2013 02:20 PM

With marvelous instructions of diyAudio wiki and some appropriate conductors (finally splits my emu), my emu has repaired 90% almost.

I must changed three power converters.

But, I have problem with phantom power, still. 0V!

As I saw to the wiki, the part U10 (PHOI) has the responsibility for the 47V (probably).
I measured the round area of U10 to mine emu and an other well function emu.

At the photo attachment, with yellow notes are the identical voltages btw two emu's. The red ones are differences and in brackets are mine values.

I thought the problem was to U10. I found a PHKI (same but with a less current) but it is nothing changed, unfortunately!

Any suggest, please!

http://www.diyaudio.com/forums/attac...1&d=1358176092

lemon 15th January 2013 11:04 AM

1 Attachment(s)
For some reason the attachment photo, seems to appearing to my computer but not to others...

Here it again!

sidiy 15th January 2013 02:13 PM

It looks like you don't have a High (3.3V) on the Enable (pin 4) of U10. Is the top board connected and does the 48V LED come on when you press the switch?

The 48V should appear between pins 2 or 3 to gnd (pin 1) of a XLR connector, not on a TRS (6.3mm).

lemon 15th January 2013 05:17 PM

Yes, the top was connected with a long 20cm conductors (I had split the emu).

OK, I found the problem. The pin4 of U10 had a cold solder, some Chip-Quik flux and now is perfect.
PHIKI now gives almost 41V (has 1.1V the pin3, FB vs 1.23 of PHOI).

sidiy, thanks for the interesting.

arizzi 29th January 2013 05:32 AM

Quote:

Originally Posted by lemon (Post 3220947)
I bought this for parts from ebay.

Like seller told me, it damaged by opposite power polarity or by power polarity bridge, probably.

After power on, nothing is happening!
Because we have not any circuit diagram, I am looking with the continuity of multimeter the paths after power switch.

It is a searching in blind, sure! Maybe the best solution is to find the appropriate flex connector for working with the both parts open, not closed like now.

After that, I found some electronics to have a relation with the power paths. At the attachment photo I have mark some of these.
I have changed 2 of these (by yellow circles) and now lights on the green led (power on led) above headphone level, but no any other led.

1) Any suggestions?
2) Can someone find to me the appropriate code (farnell, mouser) for extra flex connector? I want to work, with both sides open.

I have a board with probably the same problem you had. After replacing the first DC/DC converter I got the green LED lighting as you got. Could you please list the component you replaced in order to get the board working? I would be really glad!!!

Andrea

lemon 2nd February 2013 11:26 PM

2 Attachment(s)
Andrea, I have note to the two photos the parts has changed with yellow circles. The last one is U10, for the other parts, must to find in my files a big photo to see what type of marks are.

Newerth 8th May 2014 12:25 PM

Sorry for necro-digging this topic, but I see there are many owners of this card here and I need some help.

I recently bought the card used and out of warranty. The card works okay but has some serious problems with cold start. Every day in the morning I have to turn it on and off and on again many, many times before it boots properly. After that, the card seems to work (and even boot) fine until I turn it off in the evening. The next morning, the whole scenario repeats.

What happens if the card fails to boot:
  • "Power on" LED is on
  • Crackling pulses come out of headphones
  • Drivers do not recognize the card
  • No other LEDs are on
  • Controls do not respond
And optionally:
  • All LEDs are on
  • Some of the LEDs are off: "Sync Status", "Direct Monitor", "S/PDIF"

Any idea what is wrong?

What I already tried:
  • Get another power supply
  • Connect the two jumper "BOOTSTRAP" pins inside and turn on the device
  • Visually check all the electrolytic capacitors inside

Thanks in advance.

lemon 8th May 2014 08:51 PM

Hi,
I think, that you must have all the time un-split the emu (with some appropriate conductors) and when this behavior happens check all the yellow marking chips (they seemed at my previous photos) for right voltages.

KlangMann 13th May 2014 01:11 AM

What does the red and orange marks say, should i connect them?


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