Geneva XL sound system repair, faulty d2audio pcb

[sailor83]

Hello everyone.

I got this Geneva XL sound system for free, on the amplifier there is some faulty components, I can't find them anywhere, would be helpful to find out what they are.

On the circuitboard they are marked by Q[and a number] so that means that they are transistors. Looks like it's 8 pin MSOP package(but without the pins) (or are they 4pin with the pins going all the way through? The one's that look healty are OL one way and about 2.7 Vdc the other way.

There are two types, one marked 7414 and the other 7415. The conduct in the opposite way. But I can't find new ones by searching for the writing on the component, can anybody help?

It looks like an S and a Delta symbol also.
The size is 3 mm x 3 mm.

(The R047 resistor is burnt as you can see)

[fzabkar]

The logo is Siliconix (Vishay).

Si7415DN and Si7414DN, P-channel and N-channel complementary pairs.

https://www.vishay.com/docs/71691/si7415dn.pdf
https://www.vishay.com/docs/71738/71738.pdf

http://www.smdmark.com/en-US/search/code?id=7414
http://www.smdmark.com/en-US/search/code?id=7415

[sailor83]

Thank you! 

No I can finally order all the components I need

[Crocker]

Hi,
could you get the Geneval XL amplifier board back to work properly? If you should still struggling with the repair of the board, maybe I can help!
I had a similar issue on the D2Audio amplifier board of my XL and it took me a lot of time and parts to finaly fix it. On five of the six channels one or two of the MOSFETs were blown-up together with the 0,047 Ohm current sensing resistors. Furthermore on the back side of the PCB multiple small transistors and 100 Ohm resistors of the current sense circuity were destroyed.

[sailor83]

Hi.

I replaced the defective p and n channel mosfets. And then they blew again.. So there is more faulty with the board. I'm going to check more on the back side of the PCB aswell, couldn't see any burnt components last time..

Do you remember what parts you used?

[strawberry]

gate driver?

[sailor83]

Gate drivers looks and measures ok.

Found some sot-23 transistors marked 2L j thats faulty. (looks like pnp 150V 200mA from what I found) Going to order them. Can't find any 100 ohms resistors on the back

[Crocker]

The following picture shows the components in question:

www.incosol.de/Scratch/D2Audio_Amp_Pic_1.png


Beside to the Power MOSFETS all these components are part of the current sense circuitry.
You should check all these resistors and transistors (4 per channel) and replace them if they are broken! If you just replace the MOSFETs and current sense resistors (0,047 R) they might blow-up again as long as the current sensing and thus limitation doesn't work properly.
Finally I got my amplified back to live but it took a lot of (micro) soldering work. Unfortunately the 7414/7415 MOSFETs are currently not available (i still got some on eBay in February) but I think you can find compatible types (>= 60V Uds, <100mOhm Rds and ~5-6 Ads).
I wish you success!