Faulty volume on Audi HU's?

[AndyMac]

Browsing on ebay and found these guys who repair the design flaw which will eventually effect all Concert head units:
http://cgi.ebay.co.uk/Faulty-Blaupu...NameZWD4VQQcmdZViewItemQQ_trksidZp1638Q2em124

 

[Staz]

they suffer from faults including

VOLUME CONTROL FAULTY
UNABLE TO TURN VOLUME DOWN
SOUND OUTPUT STUCK ON FULL VOLUME

Aren't they kind of the same thing? Or at least the first one covers the other two!

 

[AndyMac]

They're all caused by the same design flaw, but are different symptoms.

 

[dualmono21]

£95 seems mighty expensive to me
the parts would likely be in the region of pence not pounds
ive repaired a lot of amplifiers and they dont cost that much to repair
if you know what your doing
all the symptoms have exactly the same result

im sure this is something very simple such as the lead from the volume control going into the op-amp being broken
this will effectively make the op-amps go to full volume instantly and the outputs will follow suit

 

[Broken Byzan]

Its a chip failiure, but i do not know which one. A brand new unit can be had for £99

 

[AndyMac]

im sure this is something very simple such as the lead from the volume control going into the op-amp being broken
this will effectively make the op-amps go to full volume instantly and the outputs will follow suit

It's not actually simple at all, it requires a new microcontroller chip (MC68HC05 - the most expensive part of the entire HU), and reprogramming of the chip to prevent the issue happening again, so not really a DIY job.
http://www.erta.ru/review/chorus-problem_eng.shtml

Yes you can get a whole new HU for that money on ebay but it will eventually develop the exact same fault, which happens after 10,000 adjustments of the volume/bass/treble/fader etc on all models of the same design.

 

[dualmono21]

sneaky ******** purposefully designing a head unit that is already flawed
i was right with the volume control to op-amp though the chip is simply in the middle of these two

i thought about this for years thinking how easy it would be to design a system which simply goes kapput after a pre-determined length of time or usage
i wonder how many household items are exactly the same as this ????

 

[Shades]

i was right with the volume control to op-amp though the chip is simply in the middle of these two

Err, you weren't right! A) Its not the lead and B) its not simple!

i thought about this for years thinking how easy it would be to design a system which simply goes kapput after a pre-determined length of time or usage i wonder how many household items are exactly the same as this ????

Someone beaten you to it years ago... They're called Microsoft!

 

[dualmono21]

so it isnt a direct connection i got that bit wrong
the end result is the same its in between the volume control and the op- amp so i got that bit right

as for simple that really depends on if you know how to change a chip or not