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Mac II w/ DayStar 50 MHz 030 accelerator doesn't chime

thisisamigaspeaking

thisisamigaspeaking

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I'm having trouble finding much information on Mac II repair on youtube. This machine isn't chiming right now. I've replaced the two 1/2 AA batteries. There was no leakage of the batteries or obvious leaky caps. The machine is extremely clean inside. There was a RasterOps 224 video card, an Apple video card with 13w3 connector which I believe is a Portrait card, and a 10 Mbit ethernet card. It doesn't chime with all the cards removed either. Is my next step to get a 16 MHz 020 and see if it's the DayStar board? Thanks.
 
I do have a working Centris 650 with SuperMac Thunder/24 graphics if that will help me isolate any problems by swapping hardware. I've asked on the 68KMLA forums as well.
 
What an awesome setup you have? Is this a standard Mac II or a IIx? Does it chime wihtout the Accelerator card? Do you have another Mac II to try a psu swap? I have 5 systems and only 2 and a half of them work. All battery and cap leakage casulaties. I did have to recap the psus to get those working. The psu's were much easier to repair than the mainboards.
 
thisisamigaspeaking said:
Is my next step to get a 16 MHz 020 and see if it's the DayStar board? Thanks.
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What do you mean by this? Is there no CPU installed in the logic board? The machine is not going to boot without the CPU installed, even if you have a CPU upgrade board installed.

The Macintosh II uses a mix of tantalum and axial electrolytic capacitors. The axial capacitors are probably fine, the suspect would be the tantalums, you could have a shorted tantalum somewhere on the board.

The power supply too could have leaked capacitors.
 
GiGaBiTe said:
What do you mean by this? Is there no CPU installed in the logic board? The machine is not going to boot without the CPU installed, even if you have a CPU upgrade board installed.

The Macintosh II uses a mix of tantalum and axial electrolytic capacitors. The axial capacitors are probably fine, the suspect would be the tantalums, you could have a shorted tantalum somewhere on the board.

The power supply too could have leaked capacitors.
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Only the early boards had axial electrolytics. The later ones had SMD electrolytics and those are the ones that always leak. The axials are usually fine.
 
The Mac II Daystar upgrades remove the built in CPU and MMU (if installed) to put in a PDS adapter board which you plug the Daystar card into.

Mac II's generally need SMT Aluminum capacitors replaced and then you need to fix any traces that are broken.
 
Unknown_K said:
The Mac II Daystar upgrades remove the built in CPU and MMU (if installed) to put in a PDS adapter board which you plug the Daystar card into.

Mac II's generally need SMT Aluminum capacitors replaced and then you need to fix any traces that are broken.
Click to expand...
I'm not sure I want to do that amount of work since I already have another working Mac II (Centris). Is it likely the DayStar is still functional on its own? I may part the system out or even sell it complete (not sure about the monitor, may keep that due to weight).
 
Unknown_K said:
The Mac II Daystar upgrades remove the built in CPU and MMU (if installed) to put in a PDS adapter board which you plug the Daystar card into.
Click to expand...

Very strange. I've never seen a PDS upgrade that required the removal of the original CPU in a 68k machine. Usually the system needs the original CPU to perform early boot before the upgrade board takes over the system. I guess the early Mac II line did things differently.

I have a couple of 68k upgrades for two different machines. I have a TotalSystems Gemini Ultra for my Mac SE FDHD and a MicroMac LC/LCII/CC 68030/68881 upgrade that I've had for decades but never a machine to use it on. I stole the 68881 out of it and installed it in my Gemini Ultra. Also have an LC III that I upgraded to LC III+ specs by desldering the original CPU and soldering on a faster one and performed the requisite resistor changes.
 
GiGaBiTe said:
Very strange. I've never seen a PDS upgrade that required the removal of the original CPU in a 68k machine. Usually the system needs the original CPU to perform early boot before the upgrade board takes over the system. I guess the early Mac II line did things differently.

I have a couple of 68k upgrades for two different machines. I have a TotalSystems Gemini Ultra for my Mac SE FDHD and a MicroMac LC/LCII/CC 68030/68881 upgrade that I've had for decades but never a machine to use it on. I stole the 68881 out of it and installed it in my Gemini Ultra. Also have an LC III that I upgraded to LC III+ specs by desldering the original CPU and soldering on a faster one and performed the requisite resistor changes.
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It's a PDS card but there is an adapter also from DayStar to create a PDS slot from the CPU socket. It's very peculiar indeed. The accelerator is sitting at an odd angle.
DayStar_PDS_II.jpg
 
Very bizarre upgrade.

Well, we can see why the logic board isn't working, or at least one of the reasons. All of the SMD capacitors have leaked. The yellow tinge, dull solder and fuzzy hairs are dead giveaways, that entire board needs to be recapped.

Returning that board back to original spec is going to be hideously expensive if you don't have the original 68851, those things are rare and command high prices because of the Amiga community snapping them all up. I think another member here was looking for one for well over a year and eventually found one for something like $200. I don't remember if they're required for normal operation though, I think you only need one if you're wanting to run A/UX. 68020 CPUs are still plentiful and not that expensive.

That Daystar PDS upgrade board *might* work in a later Mac II series Mac PDS slot (IIci, IIvi, etc.), but it'd be criminal to separate the two due to the rarity of them. Someone with more experience with those upgrades could say for sure.
 
The Mac II adapter is for the Mac II only, there is a different adapter for the Mac IIx, and none for the IIfx.
 
The PDS card is Mac II only? I know the base board that plugs into the 68851/68020 socket(s) is Mac II only, wasn't sure about the PDS card.
 
Ahah, I thought it had been the 68881/2 socket, because I bent the pin on an interface that goes from PGA male to PGA male for the 68851 and I thought it was for the 68881/2. Hopefully I have it straightened out or can do so because it looks like it would be a pain to replace.

68851_socket.jpeg
Super dumb of me not to notice that the chip is marked on the PCB there.
 
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thisisamigaspeaking said:
Ahah, I thought it had been the 68881/2 socket, because I bent the pin on an interface that goes from PGA male to PGA male for the 68851 and I thought it was for the 68881/2. Hopefully I have it straightened out or can do so because it looks like it would be a pain to replace.

View attachment 1295084
Super dumb of me not to notice that the chip is marked on the PCB there.
Click to expand...

If it uses a 0.1" pin pitch, you can get male to male pin header strip and make up a socket by cutting a bunch of pieces to size.
 
GiGaBiTe said:
The PDS card is Mac II only? I know the base board that plugs into the 68851/68020 socket(s) is Mac II only, wasn't sure about the PDS card.
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I'm not sure what's up with the "II ONLY" notation on the connector (I assume it refers to the adaptor), but I have that PowerCache card in my Lisp machine IIci and it works fine directly in the PDS slot.
 
GiGaBiTe said:
The PDS card is Mac II only? I know the base board that plugs into the 68851/68020 socket(s) is Mac II only, wasn't sure about the PDS card.
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NO, just the adapter because it plugs into the 68851 which only the Mac II has. The Daystar PDS cards were mostly used on the IIci's where no adapter was needed but they made adapters for most of the other machines.

I have a bunch of the Daystar adapters for my Mac II, IIx, LC 2 or 3 (forget which) and IIcx (you need a socketed chip motherboard for that).
 
Wish I had a CPU upgrade for my Performa 600. It's a pig of a machine. Apple took the IIvx and slapped a 32 MHz 68030 on it and left the rest of the machine at the slower 16 MHz bus speed. The only reason I keep the machine around is because it's the only 68k mac I have that takes full sized Nubus cards.
 
I collect Nubus cards, so I have a bunch of IIx/IIfx/950/800's around to put them in and I still have stacks of cards with no home.
 
I wish I had that problem lol. I have that same problem in the PC world, drawers full of cards with no home to live in.
 
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