Troubleshooting red screen on floppy boot, but not HDD?

[WhyreByter]

Hi all!
 
I'm refurbishing an A3K/16MHz with very minor battery leakage/damage.  I've cleaned the area, and the damage was superficial.  I've replaced the battery with a button cell/adapter.  The only other work done was a simple "dust off" with a soft brush and canned air, and a visual inspection.  All appeared fine.
 
It's got 2 MB of chip ram, and 4 MB of fast ram (in 8x ZIPs).  The memory registers/appears in showconfig fine.  It's also got KS 3.1 (v 40.68) in ROMs.
 
So, now the fun part: before taking the machine apart, I booted up an original disk (Typhoon Thompson, Search for the Sea Child) just to test it out.  It worked fine, though had some very slight visual glitching.  It also booted into the HDD fine.
 
After working on it, it boots into the HDD just fine, but now the same game gives a red screen on boot.
 
Here's what I've done to try to isolate the issue:
- Tested the disk on an A2K and A500, and it works fine
- Pulled the mainboard and reviewed all my work/reperfomed visual inspection
- Pulled all socketed chips, inspected, cleaned and reinstalled
- Pulled the zip ram, and moved 1 MB of chip ram over
- Cleaned all socket contacts/reinstalled zip ram/moved chip ram back
- Verified positions of all jumpers, tried various combinations of the ROM speed jumpers
 
I tested the issue after every step above, with the same results.  Booting other disks, and the HDD work continue to work fine.
 
I also tried running an ADF of the game in WinUAE (using ROMs from my purchased Amiga Forever).  In a config that's as close to my real system config I can get, it boots fine.
 
So, to summarize, I'm hoping to find some help in sorting out why my system, after fairly minor service, gives a red screen booting a disk that it booted fine before, while continuing to boot other disks fine.
 
Thanks in advance!
Robert

[danbeaver]

Hi!  I don't know the answer, but a red screen is a boot ROM issue and you need to consider the various option about booting an A3000. There is a SOFT BOOT option to load Kickstart from HDD or Floppy and I can only assume that the motherboar ROMs are messed up and you soft booting with the HHD; thus the floppy game does not have the KS needed and can't boot. So I would investigate your on board ROMs

[WhyreByter]

Thanks for the quick reply!  As I understand it, in order to soft kick the A3K, you need to have the 1.4 ROMs.  With the 3.1 ROMs installed, it shouldn't be trying/able to soft kick.
 
I'm definitely interested in trying to test out the ROMs.  I can either do a checksum, or just get another known-good set to try.
 
Any other suggestions on why it red-screens with that game?
 
Thanks!
Robert

[danbeaver]

In the meantime, try removing the current ROMs and cleaning the "legs" with an emery-board and reinserting them. The tin legs get a layer of oxide over time that is a poor conductor

I assume the game disk lacks expected boot info so that the Amiga can't boot via hardware (dodgy ROMs) and through a lack of software. Oh sh_t!  I forgot that some games (for copy protection) load their own kickstart / OS code and work directly with the hardware; Amy might then interpret a missing piece of boot software and "call it" a ROM error; the same thing might happen if it tries to read the A3000's NV_RAM which is defaulted when the battery went bye-bye

[WhyreByter]

Thanks, Dan!
 
The legs of the ROMs were cleaned as part of the troubleshooting. I'm trying to get a transrom dump off the computer now, but, of course, my floppy drive is having "difficulties". Heck, honestly, I wonder if my drive got messed up as part of the cleaning, and it's showing itself as bad "kick rom".
 
I think I'll swap in my spare drive (though I'm not sure how well it works) while I sort out the rom copying.
 

 
Yeah, that'd be too easy... No such luck.
 
Thanks!
Robert

[danbeaver]

Well you said above that you can boot other disks, and assuming you mean floppies, then I'd doubt it is the drive itself. I know that if it only this one disk, then there has to a cause related to that disk; what does this do that others don't?  Boot from your HDD and check the disk directory; if you can't read the directory then it doing something wonky and setting up its own OS. Other ways of checking it would be to see if it can be copied with or without one of the nibble copiers. Sometimes a sector editor will give you a hint. Or try Dave Haynie's DiskSalv and see what errors it brings up (don't let DiskSalv try to repair a game disk, as it will be ruined).  If all else fails get some else's copy of the disk to check on your system. There are out there cracked copies of disks, but we all know not to talk about them (yep, it's there in several versions that have been hacked).

[mechy]

Many games that run fine on the A500/2000 will not work or work right on the 3000. whdload is your friend in this case. what could of happened is the drive somehow altered or scratched the disk is why it booted the first time. You could also have a chip contact issue,but it sounds like a case of a picky game.

If workbench is running fine i doubt its any bad chips(although paula can play a part in floppy drive problems though). I've run into a couple of A3000's with bad paula sockets from the factory-they actually had a broken intermittent pin you couldn't see. You might pull paula and check the socket contacts.

Its not unusual to see battery corrosion on parts not near the battery leakage. it seems alot of these batteries outgas.

I seem to remember some 16mhz machines had quirks also but it may be my imagination since i haven't touched one in a long time. what rev. motherboard are you using?

[r.cade]

My guess is the game (like a lot of early games) won't work with fast RAM installed.  Remove the zips (or just the first) one and see if it runs.  Likely it didn't recognize it before and ran OK because of that...

[WhyreByter]

@r.cade - Thanks for the suggestion, that sounded promising, but wasn't the case.
 
@mechy - Thanks.  I'm starting to wonder if this isn't something with the drive/circuitry that's fairly unique and getting triggered by that game.  I'm looking into other possibilities down that line.  I'm sure it's not a battery corrosion issue; that baby looks/is super-clean (thankfully!)
 
@dan - the disk shows up as "unidentified" or something like that in workbench.  Can't get to it via normal means.  Since it boots on 2 other other machines, I'm less likely to think it's the disk itself.  Some friends knowledgeable in the area say that the protection/loader isn't anything super-special, it's just a common custom dos.
 
Additional info:

I was able to, from the running system, take a dump of the KS ROM, and then use a CRC calculator (double-checked on a known good ROM from AmigaForever) to verify the dumped KS ROM, and it CRCs out fine. So, that tells me that the ROM, and everything that hooks up to it is fine.
 

I spent a non-zero amount of time trying to get disks working with the drives to get tools on, and roms off. I wasn't able to format a disk in the machine, copy files to it, and then dump it via my KryoFlux. Luckily, though, going the other way (using WinUAE to make an .adf with required tools, and then using KryoFlux to write it to disk) worked pretty well (the drive is still finicky). So, I'm beginning to wonder if A) I did something to the drive, or B) I did something to the drive controller circuitry:

 
Drive - I swapped in another drive that came with this, and got the same result. I swapped in a drive that loads that game fine on another machine, same result. So, I don't think that it's the drive itself.

 
Circuitry - Many other disks work OK (workbench, other games), so unless it's using some super-rare functionality, I don't see that being the issue.

 
Thanks for sticking with this; it's quite the puzzler!

 
--Robert

[WhyreByter]

Let me just start off with one of these:
 



 
And follow it up with an admission that I am... speechless.

 
Executive Summary:
My floppy cable was reversed *on both ends*. Switching the cable around on both ends solved the problem.

 
Detailed Summary:
When I was putting it back together, I mixed up which way the cable should go on the motherboard, so the floppy didn't work. Rather that play contortionist to flip the motherboard connector, I said "Hey! The other end is right here, I can just flip it!", completely ignoring that lines 4 and 6 get swapped. Apparently those twists are important! Thankfully, looking at the pinout for the drive, I don't think that it would have/could have done any permanant damage.
 

All, thanks for your help and suggestions!

 
--Robert

[danbeaver]

Well thank God for an "easy (on the brain)" answer!  And I learned good stuff as well; as they say on the 2-lanes of America, " Keep on Truck'n!"

[r.cade]

I would never have guessed that could cause that symptom...  

[WhyreByter]

I would never have guessed that could cause that symptom...

Neither would I...  It was some suggestions from Mr. Vince and IFW that put the thought in my mind, and everyone else helping to eliminate other options.
 
Glad it's sorted; now I can get to playing with it!
 
Cheers,
Robert