Arcam AVR300 diode replacement?

[a4c]

Hi, new member with a question here.

I have an Arcam AVR300 with the not-so-uncommon DAC problem (either won't accept digital input, or puts out lots of speaker wrecking static when you try), and am unfortunately out of warranty.

Arcams solution is to replace the digital board or to replace the zener(?) diodes I believe. If they can replace the diodes, then I don't see why I can't do it myself?

Can anyone give me a few pointers such as:

1) How to test the diodes?
2) How to know what replacements to get
3) Are they heat sensitive, ie should I isolate them when soldering in new ones?

I don't suppose there is anyone out there who has done this themselves, but if there is I'd be very greatful for your advice.

Thanks,

Phil

PS - lots more info on the problem on http://www.avforums.com/forums/archi.../t-239068.html

[teejjay]

1N5393 DIODES, BETTER ONES ARE MADE BY VISHAY OR FAIRCHILD.

[parrymike]

Did you have any joy with this Phil? I've got a dead avr300 waiting for me to have a look at. Have you got any photos of which diodes need replacing? I've not had a look inside yet but any help would be gratefully received.

Mike

[teejjay]

I was sent a diagram and instructions (by Arcam) but, try as I might, I can't copy the file (adobe) into this reply. I ordered the Diodes from Canada on ebay. Haven't had the time tofix this yet (Shiftwork) but will update once done.

regards,

Tee Jay

[parrymike]

Hi Tee Jay, I've sent you a 'private message' with my email address. Any chance you could email the files from Arcam please??????

M

[Heit]

My Arcam 300 (AVR300) has a darkened spot on the d.A. board
right underneath the 3300uf Cap.

Also, the cap has a bulging top!

Id like to obtain the PDF file with the diodes
that need upgrading. I'll be pulling this
board to replace that cap, and want to upgrade
the correct diodes at the same time, or replace the board!

The browning of the board is unnerving

[errol8000]

Hi did you ever get this sorted out?

[errol8000]

Hi can any one tell me what the U.K. equivalent of the IN5393 Diodes are I can't find them anywhere. Thanks

[errol8000]

Okay i had the same problem with mine so i replaced the diodes following arcams guide and the digital input was repaired. But now the amp sounds rubbish, there is just to much bass and very little midrange and it sounds a bit harsh. Could this be something to do with the diodes i used?


FAIRCHILD SEMICONDUCTOR


BRIDGE RECTIFIER, 1.5A, 200V, DO204

Diode Type:Standard Recovery; Repetitive Reverse Voltage Vrrm Max:200V; Forward Current If(AV):1.5A; Forward Voltage VF Max:1.4V; Forward Surge Current Ifsm Max:50A; Operating Tempera;

If some one could help that would be great.

[Mooly]

Normal diodes in a PSU should have zero impact on the sound quality (as you describe).

These should be a suitable replacement for the IN5393
ON SEMICONDUCTOR|MR856RL|DIODE, FAST RECOVERY, 3A 600V | CPC

http://www.datasheetcatalog.org/data...7ti2q1u2py.pdf

Very often when doing mods or changing components personal expectation gets in the way and you convince yourself its not as good etc when in reality nothing has changed.

Just swapping rectifiers will not alter the basic sound at all...