[Premium-Rx] WJ-8711A-3 Strange behavior

[gcd]

----- Original Message ----- 
> Front Panel EPROM:            871Y
>                                             A1A1U3
>                                             1.21
>
> DSP EPROM:                       871Y
>                                             A2 U56
>                                             05.00.00
>
> Internal Control EPROM:      8711A-3
>                                             A2 U12
>                                             01.00.00
>
> The DSP PCB has the following numbers printed on it:
> 08 95 6259 -01
> 14632ASSY
> 797214 A

Hi,
Two suggestions re the odd behaviour you've observed.
1) Check the DSP chip itself - is it a DSP56000 or DSP56002 or DSP56004. I 
don't have an 8711 or 8711A service manual but
my 8711 and 8712 use a DSP56001 and I believe the 8711A uses a DSP56002 or 
DSP56004. I suggest this, as at least one 8711A-3 I saw on ebay
had an 8711 processor board in it, at least that one also had 8711 eproms.

2) The eprom sockets are not through hole, inspect the eprom socket 
soldering for cracks. My 8711 behaved a little strange
when I got it and found that one socket had solder cracks at the base of a 
few legs on one eprom socket.

Cheers
Greg
VK3XYZ