Date   : Mon, 15 Aug 2011 11:36:34 +1200
From   : car@... (Chris Reece)
Subject: Advice on restoring a dead Beeb?

On 15/08/11 09:57, Peter Coghlan wrote:
>> Power on.  I'll establish what the behaviour is with a break-induced reset.
>> (All I recall from when I tried it without a logic probe to watch was
"nothing happens" so
>> I'll need to do that again just a little more rigourously.)
>>
> Ok. So when you power on, you get the usual random drone noise which stops
after the
> usual second or so and you don't get the expected beep afterwards, just
silence?

No. My memory of the Beeb startup is that power-on results in a 
"buuuuh-beep!" noise.  What I get is "buuuuuuuuuuuuuuuuuuh" continuous, 
never-ending tone.

> And when you press break or control-break you just get silence, no beep?

Nothing stops that continuous tone except switching the Beeb off.  
Hitting break doesn't interrupt or suspend the tone.

> Do you mean the noise is coming from the speaker in the Beeb or the speaker
in the TV?
> Noise from the TV speaker is expected as the Beeb does not include sound
on the TV
> output so it is a good idea to turn down or disable the sound output from
the TV.
> A continuous drone from the Beeb speaker indicates that the sound IC is
not getting
> reset at power on.

I'll get a probe on that.

> Other than the channel/tuning issues and differences in the sound frequency
which is
> not used by the Beeb, the NZ and British TV systems are very compatible.

That's good news.  I'll persevere.

I've also been contacted off list by a local (well, he's nine hours' 
drive away, but that's fairly local) whose brains I shall shortly be 
picking to answer these questions authoritatively.

> The DFS is in a reasonable position. The OS ROM socket is also occupied
- this is also good.
> The two similar ROMs should have slight variations in what is printed on
them giving clues
> as to which is which. However, I can't make out the numbers from the photo.

Yes, that was my problem, too.

In retrospect, I probably shouldn't have set about reseating anything.

However, I received the Beeb at work, where I had no TV to plug it 
into.  I'm probably not alone in being so excited by my new toy that I 
just had to find *something* to do with it.

:/

Chris.