Hello,

My BC9500 had its battery changed, and after that, its FM frequency display has been of for about +0.3 Mhz.

Is there a simple pot somewhere to tune? 

Or some more drastic?

It's located pretty far from where I got it serviced, so I'm not very keen in getting it back there.

BR,

Pekka

The frequency display is calculated by the CPU, after a fixed divider circuit drops the oscillator frequency to something the 8032 microcontroller can follow... so nothing to tune. Unless anybody else has better ideas, I'd say the CPU is not running at the same or stable clock frequency anymore. This could happen for example if the 11.0592 MHz crystal was bumped or somehow damaged during the battery swap. I believe both are located close together inside the metal can...

Is the frequency display still stable, and can you check if it is off by a similar percentage on AM as well?

The FM and AM displays can be corrected using the procedures on pages 7-11 and 7-12 in the service manual.

Looks simple enough.

OK, that'll be easier

Funny they don't mention that this needs to be done after replacing the battery... but then again even the service manual wants you to replace the whole module instead!

joeyboygolf:

The FM and AM displays can be corrected using the procedures on pages 7-11 and 7-12 in the service manual.

Looks simple enough.

OK, thanks Graham!

If I got it right, I need to open the set to service position to remove the glass panel, to get access to the TESTMODE plug.

I'll give it a try during holidays.

Pekka

No need to open.

Just remove the lower glass - one screw under the left front corner and slide the glass to the right.