What's Wrong With my Wadia

[JedS]

My Wadia DigiMaster X32 DAC has outsmarted me.

This unit is connected via co-ax to a Wadia WT3200 transport.

When the DAC is power on it plays correctly for between 5-7 mins. It then develops a splutter. The bitrate indicator light begins to fade in and out and finally the light and the music disappear. However the unit is still powered. All other selections such as the input selector lights still change and it can be turned into standby.

If the unit is then allowed ten mins disconnected from the mains, it will play correctly for between 5-7 mins again.

More interestingly if this unit is disconnected from the transport and it is turned on to decode, it will indicate the relative bitrate selected as it would connected (this is normal). It then remains on for between 5-7 mins until the splutter begins and the light disappears.

I have her lid off to check for anything obvious, but it is time to get messy. The unit is unmodified and previously untouched.

Please help me save her.



Bitrate lights are seen on the left. The selector button is to the left of the last of the three lights.

[poynton]

Sounds like a regulator or something in the PSU section is overheating

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[JedS]

Originally Posted by poynton

Sounds like a regulator or something in the PSU section is overheating

.

That simple? I have not run it for longer than it takes to reach its stutter.

[poynton]

Take the lid off and refit loosely.

Switch on and wait for it to go wonky.

Switch off (remove plug from mains) and quickly remove the lid.

Check the regulators with your finger tip for one that is overly hot.

Also look for 'bulging'capacitors or ones showing signs of leakage ontothe PCB.

Andy

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[JedS]

The issue seems partially heat related.

When the lid was removed, the DAC played for ten mins. Double the time normal time. However after allowing it half an hour to repeat this test, it was determined not to work. The bitrates selector light does not indicate anything.

She has entered the silent age.

There was no obvious heat discrepancy between the rectifiers (she uses 7805CT and 7905CT rectifiers)

There is only one big cap (6800 uf 25v) and this cap seems in good order. Two smaller caps (1000 uf 25v) finish up a what appears to be a fairly simple PSU.

Help help help!

[marce]

There may be local supplies for some IC's a schematic would help.

[renaudagnes]

Maybe you can see with these guys here, it seems they know perfectly what this kind of baby is made of.

[analog_sa]

Originally Posted by JedS

There was no obvious heat discrepancy between the rectifiers (she uses 7805CT and 7905CT rectifiers)

Calling these "rectifiers" - not a good sign. Instead of asking in forums just get someone qualified to look at it.