This was in a Blackout I just picked up... it doesn't match what is shown in the assembly diagram in the manual that is available online (as the battery holder is upper left, rather than bottom right as in the manual) Wondering if its from a different generation??? or just a revision...or what? Point is I would like to find an accurate schematic/layout diagram so I can better diagnose why it isn't booting up into attract mode.

EDIT: SOLVED its system 4. Code on the bottom right of the board (under the driver board) ends in -4.

IMG_5577.JPG

Lower right? Like the spot with two layers of white out on it??? ; ) Looking up sys 3-4 to see if I can find a positive match, thanks guys!

Barakandl and LTG win. Found the part number, conveniently located where you can't ever see it with the driver board plugged in. Thanks Williams! It is sys 3.

Looks like is is actually the 'revised' sys 3 board... page 2a of this disco fever document: http://mirror2.ipdb.org/files/686/Williams_1978_Disco_Fever_Schematics_paginated.pdf

Thanks again dudes!

Soooo... given the ID number on the lower right ID-2001-133... I looked that up in the googles but the only hit I get is Ebay adds that say its the 3 (many of which have been upgraded to 4)

But this little guy is in a BLACKOUT... thats system 6... does THAT work???

This link, thinks so: http://techniek.flipperwinkel.nl/wms37/index2.htm

Control+F for : Converting a System3 CPU to System4.

But again, I think this board is Revision 2 of system 3 so its a bit different and doesnt have a trace between pins 6 and 7 on IC15.

This Doc confirms that the extra socket under the battery holder means it is Revision 2: http://mirror2.ipdb.org/files/686/Williams_1978_Disco_Fever_Schematics_paginated.pdf

But... it doesn't have a schematic for one of them, so I can't quite confirm what trace is is that is meant to be cut and re jumped for Revision 1. I'm kinda assuming Revision 2 just changed that already on the board... given this was in a sys 6 game. The guy I bought it from says it worked... can't be sure I guess... but I did see it go in to attract mode once at least.

I think what happened is that the flipper roms were both upsidedown for a good bit (#@$#ing lables were on upside down!) and I know one of them got real hot. I got new ones in the mail but I'm not quite sure they are actually the right chips given this is a super weird case of a sys 3 running sys 6 ROMs. But, hopefully the fresh roms (and making super sure they are in correctly) will fix it or at least let me see what else is actually wrong so I can get on to bulletproofing and learning to restore playfields.

Thanks for the help guys, let me know if you have any other advice on the sys 3 as sys 6 weirdness!

Edit: There is also one pin on the power supply that has two wires jammed into one slot... both wires run to the Display Board. Is that normal, related, or unrelated? I seem to remember seeing a 2 wire to 1 pin thing somewhere else too, but now I can't find it.

Thanks for the clear info Barakandl, thats really helpful to confirm compatibility from 3 to 6a.

Tech questions: Is 2716 'normal' for those IC chips? I ordered replacement roms, but they didn't specify what chips they were on... are there other options?

Also, if I may double check my google-fu against a real live human:

ROM = read only memory, like the chip that comes with your game, manufactured as that games software
Prom = Read only memory, manufactured blank (no software burnt on it)
EPROM = Rewriteable memory

You mentioned eprom's specifically in your post, are you useing those terms interchangably or do I specifically need EPROMS for some chips?

I am familiar with that mod, however my board is a bit different ( I'm almost assuming that mod is build into my board but I can't quite be sure until I compare the two schematics very closely[working on this currently...])

Below is a pic of my board (revision 2 system 3): note there is no trace running between pins 6 and 7 on IC15, BUT there is already another pad linked to pin 1, could this be the mod already included from the factory?

IMG_5583 (resized).JPG

I don't think I can ID what trace that is on the schematics without having a revision 1 board to look at... or good pics