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Automotive section => Car radio repair => Topic started by: delambo on December 07, 2007,18:51:10

Title: Audi Concert and Chorus volume problems.
Post by: delambo on December 07, 2007,18:51:10

These units suffer with a common problem of uncontrolable volume.  You sometimes turn the volume down and it goes up full, sometimes it goes down full, other times it does just exactly what it wants to do!

REPAIR:

Replace Motorolla 68hc705b16 with 68hc705b32 with modified dump (for permenant repair)

Part available from http://www.sapsuk.com

Title: Re: Audi Concert and Chorus volume problems.
Post by: M1DJF on May 23, 2009,12:47:47

Quote from: delambo on December 07, 2007,18:51:10

These units suffer with a common problem of uncontrolable volume.  You sometimes turn the volume down and it goes up full, sometimes it goes down full, other times it does just exactly what it wants to do!

REPAIR:

Replace Motorolla 68hc705b16 with 68hc705b32 with modified dump (for permenant repair)

Part available from http://www.sapsuk.com

i found if you reprogram this mcu it cures the problem with out replacing  mcu :thumbup:

Title: Re: Audi Concert and Chorus volume problems.
Post by: delambo on September 04, 2009,06:22:41

Quite right, but this is only a temporary repair.  The problem is caused because every turn of the volume control is recorded in a memory table in the eeprom, when the memory table is full it goes beack to the start of the memory table but cannot over write so it follows the proviosly stored volume levels.

Re-programming will clear the memory table but it will become full again.  My replacement processor will not have this problem.

Title: Re: Audi Concert and Chorus volume problems.
Post by: yogi972 on October 05, 2009,16:39:36

Hi there,
My wife's tt has the ol' volume prob, and searched the web for ideas on how to repair

Im pretty handy with a soldering iron.. (sparky)
is this a repair i can do myself eg. put new chip in
will it be programmed ready?


I tried the link you provided but the site is undergoing maintainance :(

of am I just best sending the unit off somewhere (which I cannot find around the Midlands) (uk)

cheers muchly

Mick

Title: Re: Audi Concert and Chorus volume problems.
Post by: delambo on October 06, 2009,10:05:12

Hi,

I can supply you a processor only for £45 + p&p (about £2) but it comes without warranty for supply only due to the technical nature of fitting it.

I can supply and fit the processor for £55 + p&p (about £7) and it comes with a 1 year warranty.

You can pay by paypal, let me know what you want to do.

If you want to fit it yourself you really need a hot air or IR rework station as the chip is a plcc52 (52 pins surface mount) as per pictures below.

(http://www.tv.quuq.org/forum/index.php?action=dlattach;topic=663.0;attach=616;image)

Title: Re: Audi Concert and Chorus volume problems.
Post by: breakfast on June 12, 2011,04:29:05

thanks for this helpful information :c017:

Title: Re: Audi Concert and Chorus volume problems.
Post by: mtl on September 29, 2011,16:38:44

Quote from: M1DJF on May 23, 2009,12:47:47

i found if you reprogram this mcu it cures the problem with out replacing  mcu :thumbup:

Can you describe the procedure in details? What is needed and do you have to dismount the processor?
With what dump did you reprogram it?
Thx.

Title: Re: Audi Concert and Chorus volume problems.
Post by: nagybarni on December 08, 2011,08:28:29

Hy,

Basicly my girlfriends TT has the same trouble, and i just want to make sure, if i buy a new eeprom and replace the old one just by soldering it, it will work fine? it doesn't need anything else, programing or stuff like that?