I always put a ceramic 100nF between + and GND on my controller's power supply.

There seems to be a 1nF only here; can't see if they are ceramic - sadly I don't own a BM8000: I would put those 100nF in parallel to C16 / C46 and try again as filtering the 7805 obviously helped a little.

Just a thought....

  Gunther

 

How strange, and frustrating Jacques, I feel for you mate! Definately sounds like a noise issue! How do the little supply inductors look? They aren't unwound / distorted or otherwise in-effective are they? Have you looked at the crystal area I am sure it isn't impossible to have a minor stability issue that throws off certain functions...? How about a small decoupling cap actually across the micro supply pins and lay the thing across the chip body? I dunno, funny ideas for a funny problem!

Hi Olly,

The inductors are fine. Do you mean the crystal itself could be the cause of the problem?

The frequency counter increments fine (displays correctly) but I'm not a processor specialist... Some kind of instability happens somewhere but I can't see it. I wish I knew how to test a processor!

Thanks for suggesting this. A new 2MHz Xtal, perhaps?

I guess it is a bit of a stab in the dark Jacques but unless anyone else thinks otherwise you not got a lot to loose? Of course, you still can't entirely rule out the processor but it is looking much less likely now!

Opening that can again... not something I'm looking forward doing!

Put a hinge on the thing

Step1:

Put a hinge on the thing

Opened the can again. Nothing wrong in there... Xtal just fine.

Checked the protection zener (D6), the cap (new). I get 4.93V, 4.97V with processor unplugged. 

I'm going to give up, unless someone comes up with:

1) a stroke of genius,

2) a processor board for rent! 

 

 

Did you already try the 100nF blocking ceramic caps directly at the processor's supply as me & Olly suggested?

Yes, they are in place!

Hi all,

This is pathetic. Still no idea what to do. Ever since the 7805 change the tuner has remained stable, but it won't go over 102 MHz.

I haven't been able to source another processor board. The last Beomaster 8000 receivers I saw on eBay were sold for ridiculous prices and they weren't even nice to look at!

 

How much are they going for Jacques? I figured they must fetch a fair sum but as I have not yet seen one sell on UK ebay I haven't a clue what they are worth!

Hi Olly,

Well the last one went for 380€!

It wasn't even looking good...

Olly, I still have that Beocord 9000 pinch roller for you!

 

Hi,

Finally found the remote... but still no processor module!