PROPHET64 & MSSIAH Userforum




Official information and support forum for
MSSIAH and all PROPHET64 versions.



You are not logged in.

#1 2012-03-19 16:16:15

Anodyne
GI-Joe
Registered: 2007-12-09
Posts: 15

SID2SID build issues

I've quadruple checked all my connections with a continuity tester, and tested the C64 and SID's (with MSSIAH's diagnostic tools) prior to installing, but when I install the SID2SID the computer just comes up with either a garbled screen or a bunch of vertical lines.  My first thought was that it's a blown timer chip, but I don't know how that could have happened since I covered it with electrical tape before installation and specifically kept an eye out not to short anything, and the system appears to work just fine when the board is removed (it again passes MSSIAH's diags). 

This is the second SID2SID I've built.  The first one was for a 6581 machine, this one's for 8580's.  Aside from the filter capacitors, I'm using parts identical to the first board (which is working fine).  I am using the 2N2222A transistor (works on the 6581 build, however I've posts about how they aren't supposed to work).  Could this be the problem? 

I'm hesitant to start desoldering stuff because this same exact transistor type is giving me no trouble in my first installation, but at this point I don't know if there's anything else left to try.

Thanks for any advice,
Owen

Offline

 

#2 2012-03-20 17:20:14

Anodyne
GI-Joe
Registered: 2007-12-09
Posts: 15

Re: SID2SID build issues

Ok, so I went at it again and... there was a problem with the socket on the motherboard, or the legs on my SID2SID long-legged socket.  Pins 1 and 7 on the right side of SID1 were not connecting with the motherboard even with the SID2SID fully inserted.  I ran wires from those pins to the bottom of the motherboard and now, the C64 powers up and recognizes SID1.  Progress.

But now, if I insert SID2, the computer won't start. Take it back out, it works again with only SID1 installed, and I've switched them around to be sure it's not an issue with the SIDs.  I'll keep looking...

My question here is, could the wrong transistor type being installed (2N2222A vs. 2N2222) cause the machine to not start up at all with both SIDs installed?  I thought the transistor, at worst, could cause the second SID to be quiter but that's about it.

Last edited by Anodyne (2012-03-20 17:25:09)

Offline

 

Board footer

Powered by
© Copyright 2002–2008