Chorus volume problem

bob13

bob13

Member
Just had a strange problem with the volume on my chorus cassete player, it only stays on very loud or no volume at all no matter how much i turn it left or right.
Just to mention that if i select bal or fad or other options it adjust them fine, only on volume it doesn't work.
Anyone experienced this?
Thanks!
 
you have the famous audi / vw / blaupunk head unit volume control issue. Essentially the stupid programme in the headunit would rewrite the volume level memory for every change you make to the volume (so it knows what volume to put it back on when you restart the car). The persistence memory cell has limited re-write cycle and once 'worn' it doesn't register inputs as correctly. The cell is also temperature dependant and seem to be worse when cold. There is no fix apart from replacing the motorola chip which uses tiny surface mounted soldering and reprogramme it to avoid excessive use of the cell. I think some russian coders rewrote it but you'd still need someone to replace the chip. Buying another factory unit and you're simply waiting for that to happen again.

I know there is a service on eBay, but it is not cheap, about £90, who claims to reprogramme with a new chip soldered in. I've not used it myself but I've been meaning to.
 
As humps said. I got a correct dump for Motorola chip, but I cannot get anyone to reprograme the chip, because it has some special connectors. You can try to get Matsu****a unit from Ebay, but they go for around 130 GBP. They do not have the same problems (sorry, Matsu****a is for Concert, do not know if they were manufacturing also Chorus). 80 GBP is the service to repair it, I found one local in Slovenia for 80 EUR.
Temporary solution could be that you put a tiny light bulb on the chip, that will warm the chip. This works, but through time also this will not help.
 
Thanks to both of you for the answer, i don't want to change it for an aftermarket unit, does the never ones have the same problem and is it a straight swap?
I'm thinking of concert1 or 2 maybe?
Also where is this chip located inside the stereo?
 
if you have concert1, your car is likely to be 2001 or older that hasn't got full CAN-BUS. This means upgrade to concert 2 requires a CAN-BUS simulator device for full function including the backlit, power on/off. There are a few threads here about concert2 upgrading. I'd rather have someone to reprogramme my Concert1.
 
bob13 said:
just browsed few forums and found this link for the part to replace:

http://www.codecard.lt/electronics/...chorus-car-radio-8-925-904-252-/prod_314.html

i should be able to find someone to replace it.
Click to expand...

Ouuuuuuuuoooo. Nice find :). Great price.
Replacing can be done by every electronic man. The problem is programming it, because you have to have the proper base to put it in and programme it.

PS: As far as I have researched this topic I think there are two versions of Motorola chip. So maybe would be better you to open the radio and check which one you have. It is easy, only four screws, though you have to have special tool for getting the radio out (few pounds on Ebay and 14 days of waiting to be delivered :)).

Also a picture of the chip (bottom large Motorola chip) that should be problematic:


I would also like to keep the original radio because it has CD changer :).
 
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VonB said:
I had the very same problem and thanks to this thread : http://www.a2oc.net/forum/showthread.php?6848-Has-anyone-fitted-a-Parrot/page4

plumped for the clarion unit (post #33). Although not OEM I still think it's a lot more interior friendly then most other ghastly after market head units, and I'm very happy with the bluetooth audio/SD card fuctions. Also at £60 +P&P (new!) from ebay - to repair the concert unit seemed crazy.
Click to expand...

I must say it realy looks god, maybe i'll change my mind after all and i'll consider going aftermarket route BUT i coudn't find one unit under 120 pounds.
 
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mtl said:
Ouuuuuuuuoooo. Nice find :). Great price.
Replacing can be done by every electronic man. The problem is programming it, because you have to have the proper base to put it in and programme it.

PS: As far as I have researched this topic I think there are two versions of Motorola chip. So maybe would be better you to open the radio and check which one you have. It is easy, only four screws, though you have to have special tool for getting the radio out (few pounds on Ebay and 14 days of waiting to be delivered :)).

Also a picture of the chip (bottom large Motorola chip) that should be problematic:


I would also like to keep the original radio because it has CD changer :).
Click to expand...

Thanks for the info and photo, i didn't know i will have to programme it, what do you mean with VAGCOM?
 
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bob13 said:
Thanks for the info and photo, i didn't know i will have to programme it, what do you mean with VAGCOM?
Click to expand...

The chip on the link is already programmed, so no problem with that ;). Nope, not with VAGCOM, special programmator. Old one out, new one in. 10 minutes of work for an electronic.
Anyway, tried to order it, but the bank account number for bank transfer is not correct. Little suspicious...
 
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Some other forums suggested that i should try to remove the volume rotary knob and spray WD40????
Anyone tried that?
 
bob13 said:
Some other forums suggested that i should try to remove the volume rotary knob and spray WD40????
Anyone tried that?
Click to expand...

If the volume doesn't always change when you move the volume control knob (rotary encoder) or if the volume occasionally goes down when you turn the encoder 'up', then there's an issues with dirt in the encoder. This can be remedied with a bit of switch cleaner. But the issue where the head unit is either at max or min cannot be fixed by just cleaning the rotary encoder; it's an issue with a chip.

Cheers,

Tom
 
timmus said:
If the volume doesn't always change when you move the volume control knob (rotary encoder) or if the volume occasionally goes down when you turn the encoder 'up', then there's an issues with dirt in the encoder. This can be remedied with a bit of switch cleaner. But the issue where the head unit is either at max or min cannot be fixed by just cleaning the rotary encoder; it's an issue with a chip.

Cheers,

Tom
Click to expand...

I will give that a try but the question is do i have to remove the stereo and use the cleaner inside the unit or is it a matter of pulling the knob out and spray behind?

Cheers!
 
In this digital age I did not think radios still used the old potentiometer volume controls which responded well to having the contact tracks cleaned.

Cheers Spike (OAP)
 
timmus said:
Yeah, the knobs just pull off.

Tom
Click to expand...

Any hint's on how to take it off?

I tryed to pull it with my fingers and no luck and then with a pair of pliers and a bit a cloth around it and as hard as i pull it won't come off.
 
Um, I don't have any suggestions, I'm afraid. All those I've tried have just pulled off, offering just a little resistance. Is it possible that it's been glued on by a previous owner, having been broken?

Tom
 
Well, I went for the chip on the link above.
I paid it on Monday evening, today the package has been already delivered. Also communication was excellent, so until now thumbs up. I will install it during the weekend, hope this will fix the annoying volume problem :).
 
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