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Should I get a Rominator II?

croissantking

Well-known member
Thanks for all the tips so far. I guess I'll be doing some troubleshooting - lots of variables to test, but RAM does seem like a possible culprit in my mind. There is also a chance I bodged the recap I did, but hopefully not.

Sorry to go off topic again, but I need to do something about the reset button on the logic board as it's failed, confirmed it with a multimeter. Can you still get these parts?
 

croissantking

Well-known member
An update on this — done absolutely loads of troubleshooting:

- Installed brand new 16MB eight chip SIMMs in bank A, with the stock 1MB SIMMs in bank B
- Installed the stock RAM in Bank A, with some more eight chip 1MB SIMMs in Bank B
- Tried the just the 16MB SIMMs in Bank A
- Went back to the 8MB config
- Removed the 4GB SCSI hard drive I installed, and put back the original HD40 with a clean install of System 7.1.1
- Reflowed the connections to the PAL chips
- Reflowed the connections to the ROM socket
- Checked all the traces from the ROM socket to the CPU for continuity
- Checked PSU voltages with a multimeter

None of the above made any difference and my symptoms are identical to @beachycove. Random bus and address errors - or just lockups - particularly on cold boot. Also, invalid checksum err on known good disk images is another symptom that pops up when the SE/30 isn’t happy.

It does feel like a RAM problem, but I’ve tried all these different modules, so it probably isn’t.

One thing I did look at carefully is the way the ROM SIMM fits into its socket, because I’ve had issues with an intermittent connection. It seems that, using a rubber band to give it support, keeping it held as far forward (past the point where it clicks into the slot) as possible has helped with stability. In fact, it helped so much that I actually thought I’d solved the problem the last few days as it’s been running so well. However, it just bombed out on me while I was changing a desktop pattern this morning so there is still a problem.

It’s downheartening that it’s not working reliably but one way or another I’m determined to get a fully working SE/30.

Next step is to put the motherboard in the dishwasher and then dry it out properly. I also plan to recap the Sony power supply as there is quite a lot of electrolyte goo on the board and it would be good to rule this out.
 

LaPorta

Well-known member
Even better, put it into the Startup Items folder of a Mac someone else might use, as a prank.
That was one of the best ones in Macworld MacSecrets back when. That, along with the system bomb dialog startup screen. Unfortunately today, with the speed of startup drives, you probably would start the computer before convincing the user to turn the machine off :p.
 

mikes-macs

Well-known member
For what it's worth, I've had memory issues before with a Mac SE/30 because I mixed different brands and speeds of memory modules installed. The minimum RAM speed for a Mac SE/30 is 120. The lower the number, the faster the chip. So a SIMM faster than 120 would work but you need at least four of them. Learning how to read the speed and size of a 30 pin SIMM is key. Try not to mix brands and speeds. I need a magnifying glass to read the writing as many have faded over the years. Example here is a 1MB 30 pin SIMM.
The example chip here is the MT 4C1024DJ -10. The 1024 indicates this is a 1024 kb SIMM. The -10 indicates the speed is 100 (they leave out the last zero) so if you see a -12 that is 120. Try to match in fours all with equal amounts of chips on the SIMMs.
Also when removing the motherboard from the chassis be sure you are careful as it is possible to unsolder the RAM socket just by moving it and grabbing it from underneath inadvertently. I had this issue on one of my SE/30s. If I turned over the board and looked at where the SIMM sockets are I can see the solder connections on 2 of the Bank B slots were loose. I quickly realized that bank B could not be used until this was repaired. So now I GENTLY remove the motherboard from the chassis slowly and and place it on it's RF shielding piece it comes with, to work on it.

One thing a Rominator II can do is your SE/30 can bypass the memory test at boot avoiding large delays at boot time with large amount of installed memory.
Also I like the emergency RAM disk ROM Disk feature.
 

croissantking

Well-known member
For what it's worth, I've had memory issues before with a Mac SE/30 because I mixed different brands and speeds of memory modules installed. The minimum RAM speed for a Mac SE/30 is 120. The lower the number, the faster the chip. So a SIMM faster than 120 would work but you need at least four of them. Learning how to read the speed and size of a 30 pin SIMM is key. Try not to mix brands and speeds. I need a magnifying glass to read the writing as many have faded over the years. Example here is a 1MB 30 pin SIMM.
The example chip here is the MT 4C1024DJ -10. The 1024 indicates this is a 1024 kb SIMM. The -10 indicates the speed is 100 (they leave out the last zero) so if you see a -12 that is 120. Try to match in fours all with equal amounts of chips on the SIMMs.
Also when removing the motherboard from the chassis be sure you are careful as it is possible to unsolder the RAM socket just by moving it and grabbing it from underneath inadvertently. I had this issue on one of my SE/30s. If I turned over the board and looked at where the SIMM sockets are I can see the solder connections on 2 of the Bank B slots were loose. I quickly realized that bank B could not be used until this was repaired. So now I GENTLY remove the motherboard from the chassis slowly and and place it on it's RF shielding piece it comes with, to work on it.

One thing a Rominator II can do is your SE/30 can bypass the memory test at boot avoiding large delays at boot time with large amount of installed memory.
Also I like the emergency RAM disk ROM Disk feature.
I currently have the original 1MB SIMMs in bank A. They are eight-chip, 100ns TI chips. In bank B I have nine-chip 1MB SIMMs with identical TI chips as those in bank A, but 70ns. 8MB total.

I originally thought my issues were due to having 32-bit addressing on, but I've since ruled this out.
 

mikes-macs

Well-known member
I'm thinking there's more going on with the board than memory issues. I don't think a Rominator II will be helpful at this time until the issues are resolved.
 

croissantking

Well-known member
I'm thinking there's more going on with the board than memory issues. I don't think a Rominator II will be helpful at this time until the issues are resolved.
I agree. When I got it, it had already been re-capped. The board looks very clean but it's possible there is some residual electrolyte hidden under the various components. So I will wash it thoroughly as I have not done this yet, and report back after further testing.
 

mikes-macs

Well-known member
On another note.
I believe the Rominator II is based on the Mac IIsi ROM. Which at a point in time were highly desired for the SE/30, also the Mac IIfx ROM. The IIsi ROM is 32 bit clean and works fine in the SE/30 but they are rare as most Mac IIsi have the soldered ROMs. I managed to buy 2 that had ROM SIMMs after I had already bought 3 Rominator 2s. I've had great results with all.
 

joshc

Well-known member
Slight change of topic. For quite a while now, I cannot access Macintosh Garden. I have used several browsers and all are no go. Is it down?
It's not down. Probably your connection/network or your IP has been blocked? Try from a different connection/network first I think.
 

croissantking

Well-known member
I agree. When I got it, it had already been re-capped. The board looks very clean but it's possible there is some residual electrolyte hidden under the various components. So I will wash it thoroughly as I have not done this yet, and report back after further testing.
An update:

I dishwashed the motherboard twice, and then recapped it again, with better quality components. I also took the opportunity to recap both the analog and power supply boards, and have it all back together again.

It doesn't boot – gets stuck at the flashing question mark, but in slow motion (i.e. flashes very slowly). Doesn't pick up the hard drive, and when booting off a Disk Tools floppy it freezes before it gets to the desktop.

So I've either done more damage, or something's not reassmbled correctly.

I think I need to call it a day with this particular logic board because it's beyond my ability to diagnose.

I've seen JDW's videos about how he built a new SE motherboard from scratch ('SE Reloaded'). Is it possible to do this with an SE/30?
 

croissantking

Well-known member
I didn't rinse with IPA because the board came out of the machine looking sparkling clean. It's been sitting around for weeks, so think it should be fully dry?

Yes, I did recap the power supply. I used high-quality brand name components. I checked voltages prior to recapping it (they were good), but not since.

I'll take some large photos of it tonight.
 
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joshc

Well-known member
Nice tidy recap job there. The board does indeed look clean but I only mentioned rinsing with IPA as water/dishwasher liquids usually leave residues on the board and IPA will displace those.

Check F3 fuse, if my memory is correct, that's for internal SWIM/SCSI.

After running is the SWIM (UJ11) red hot?

A bad SCSI chip is also a possibility if there's no SCSI activity at all.
 
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