Date   : Fri, 05 Jun 2009 17:33:19 +0100
From   : pete@... (Pete Turnbull)
Subject: Issue 4 will not accept a 1770

On 05/06/2009 17:12, Andy Ford wrote:

> I did check a couple of the pins in IC78' socket, but not all of them. 
> Now you mention it, I do remember something about a PCB that had a pin 
> bent at the factory...

I've had one like that.  A good way to make a reasonably good check is 
to remove the board and just see if all the pins are apparent on the 
non-component side.  Not 100% foolproof (I've had one socket where the 
soldering was fine but the pin was actually broken between socket and 
PCB) but pretty safe.  In the case of the broken pin, the symptom was 
that things worked for a few minutes, but as the machine warmed up, the 
expansion raised the socket just enough to break the connection!

> I was half hoping it would be a simple case of, just try replacing X 
> etc

A bit of a long shot, but are you sure the DFS ROM matches the rest of 
the interface?  I seem to remember that some Watford ones expected the 
FDC chip at a different address to Acorn's, but others didn't (Solidisk 
did the same).

-- 

Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York