Need assistance with A3000D ROM 3.1 upgrade

[bjjones37]

I have and Amiga 3000D that I purchased a BigRAMPlus card for.  It is currently configured to softkick Kickstart 3.1.  When I put in the memory card to the Zorro slot at bootup it says that the card is defective.  I assumed that is was because I was using 1.4 to softkick 3.1.  So I purchased new 3.1 ROMs and installed them.  All I got was a black screen.  The installation picture provided by the vendor shows a different version of the motherboard than mine.  I have Rev 6.1. 

The example picture shows bare solder pads where the ROM jumpers are supposed to be. Mine has Jumpers J180 and J181 both jumpered 2-3. Do I need to remove these?

I have the Alpha 5 ROMs in sockets U182 and U183 on my Rev 6.1 board where example board is bare solder pads. Are any special modifications required? Because pulling out my ROMs (or should I have left them in?) and putting the 3.1 ROMs in U180 and U181 simply did not work.

If someone who has done this before can give me some tips I would appreciate it.

[Boing-ball]

@bjjones37

First off, on the A3K. Which Buster chip are you using? Have you tried all Zorro slots with the card?

The ROMs you pulled. When you put these back in, does the system work again?

From videos I have seen of Chris Edwards YT channel. I am under the impression the Revision 6 boards require something called a ROM tower. So simply just plugging in new ROMs without the tower part may not work.

[bjjones37]

I have Superbuster-11.  I cannot remember how many Zorro slots I tried.  And when I put the Alpha 5 ROMs back in the A3000 softkicks just fine.  I would not even have bothered with buying the ROMs if the memory card had worked.

I had tried the same memory cards (have two) in my A4000 and it cannot see them at all.  At least the A3000 sees them as defective. I tried all of the Zorro slots on the A4000.  I tried probably two on the A3000.  I notified the vendor what my board version number was but he had no other instructions.

[Jope]

Rear sockets U182 and U183 are for 27C220 type chips and the front sockets U180 and U181 are for 27C400 type chips. You can only have one set populated at a time.

Early A3000s need a ROM tower if U180 and U181 are used. It is unclear to me which revisions truly need it. 7.1 definitely needs it and 9.0 definitely does not, but this is not all of the revisions. :-)

U182 and U183 are always the correct 27C220 pinout in A3000 motherboards.

1.4 ROMs do not stop you from using a Z3 memory card, I have this combination in my A3000, but I forget which revision the board is now. It has a ROM tower and IIRC it is 7.x.

I found a few more data points here:
https://www.amigalove.com/viewtopic.php?t=1339

7.3 boards shipped with ROM towers, 8.9 did not need a ROM tower.

Most likely 6.9 will need a ROM tower too if 27C400 style ROMs are to be used.

An educated guess is that all of the people who burn KS ROMs for sale currently will do 27C400 chips and aren't aware of the tower-less 27C220 possibility for older A3000 revisions.