gong repair

[shogun]

Just wanted to add some hints to this old thread, unfortunately it is not possible to add directly as the case is closed.
http://www.bimmer.info/forum/showthr...t=gong+speaker
http://www.bimmer.info/forum/showthr...t=gong+speaker

Speaker in the gong has 80 Ohm, and they are not that easy to get.
In case you replace it by an 8 Ohm speaker, you have to install a resistor of 75 Ohm in series. But this reduces the loudness of the speaker.
In case you just install an 8 Ohm speaker without reistor, then you send your chip into Nirwana = dead.
http://img72.imageshack.us/img72/8149/gong004ar4.jpg
http://img502.imageshack.us/img502/8827/gong003vp0.jpg

If someone has a good source for such a small speaker, let us know, because the gong is quite expensive.

[Fetch]

My gong is silent.....It's on the todo list.

[myles]

I repaired mine a while ago. I can't remember for sure, but I thought the old speaker was an 8ohm. I replaced it with a slightly smaller 8ohm speaker and it works well. I know that the new and the old speakers are the same resistance rating.

It's a little quieter, but I think its better like that.

I used this one - http://www.jaycar.com.au/productView...=&SUBCATID=621

or this one ( I can't remember the size) -
http://www.jaycar.com.au/productView...=&SUBCATID=621

[pingu]

Although most speakers are either 4 or 8 ohms, you can also get 16 ohm speakers (although it might be tricky to get these in the right size). 16 ohms would be truer to the original loudness than 4 or 8 ohms.

[shogun]

As I said the speaker has unusual 80 Ohm, not 8.This info is from the electronic expert of the German 7-Forum.

[myles]

Mine was definitely not an 80 Ohm. Maybe a different gong.

[shogun]

O.K., here is some more evidence

quote:

Repairing a silent gong...

Hi All,

Well, as I was having the radiator replaced today, I had my mechanic pull the gong out for me at the same time.

So far, I have successfully dismantled the gong, and a quick test with the continuity tester and ohmmeter reveals the speaker itself is dead - no circuit.

It is a 5cm, 0.5w 80ohm. Yes, I though 80ohm was strange too, but there really isn't a '.' between the 8 and the 0...!
A round circuit board carries a single IC (an ELMOS ICR33271E), along with some passive components and a few surface-mounted components on the underside.

Since I do not have a 12v source, I am unable to test the circuit with a replacement speaker right now.

I intend to replace the speaker in the first instance, although who knows what else may have blown?! I figure its worth 99c to try! If I can get a replacement IC, I may change that out too, although my money's on (and hoping) that the speaker itself is the culprit.

When I'm done, I may post the results on here.

Wish me luck!!



Ian

[BillionPa]

how about 10 8ohm speakers in series

[shogun]

Oh yeah, that might be like a symphony orchester then ;-)