The daemon Mac IIci: Can it be fixed?

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stephen_usher
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Re: The daemon Mac IIci: Can it be fixed?

Post by stephen_usher »

I know. And I don't want to solder wires onto vias or anything else as these boards are mega fragile and the traces break or pull off the board even if you just look at them in a funny way.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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Re: The daemon Mac IIci: Can it be fixed?

Post by rubber_jonnie »

stephen_usher wrote: 15 May 2023 14:57 I know. And I don't want to solder wires onto vias or anything else as these boards are mega fragile and the traces break or pull off the board even if you just look at them in a funny way.
I also expect that given the battery damage, manhandling the board could have added problems such as vias cracking, more traces breaking etc.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
Tomswork
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Re: The daemon Mac IIci: Can it be fixed?

Post by Tomswork »

@stephen_usher

This is a excellent resource on mac repairs and recapping guides

Tom

@rubber_jonnie

https://www.youtube.com/@BranchusCreations/videos
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Re: The daemon Mac IIci: Can it be fixed?

Post by stephen_usher »

Well, given that the system wouldn't bong until something warmed up I started testing using a hair dryer.

Warming the MMU made no difference.

Warming the RBV (video generator) allowed it to bong.

This suggests that it is the RBV chip which is faulty. Unfortunately it not only handles the video but is effectively the second half of the MMU so I don't think the system will run without it installed and with a separate graphics card.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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Re: The daemon Mac IIci: Can it be fixed?

Post by rubber_jonnie »

Tomswork wrote: 15 May 2023 20:23 @stephen_usher

This is a excellent resource on mac repairs and recapping guides

Tom

@rubber_jonnie

https://www.youtube.com/@BranchusCreations/videos
Thanks Tom :)
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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Re: The daemon Mac IIci: Can it be fixed?

Post by rubber_jonnie »

stephen_usher wrote: 16 May 2023 19:20 Well, given that the system wouldn't bong until something warmed up I started testing using a hair dryer.

Warming the MMU made no difference.

Warming the RBV (video generator) allowed it to bong.

This suggests that it is the RBV chip which is faulty. Unfortunately it not only handles the video but is effectively the second half of the MMU so I don't think the system will run without it installed and with a separate graphics card.
Oh, interesting. Can you get it to bong reliably, or is it still troublesome?
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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stephen_usher
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Re: The daemon Mac IIci: Can it be fixed?

Post by stephen_usher »

Now that I've disconnected the video cable and moved the memory into bank B, which isn't accessible by the on-board video sub-system, and warmed the RBV chip with my hand for about a minute then it will reliably bong and stop predictably, probably at the point where it scans for a video card.

So, "reliably" for certain values of reliable.

I've ordered a Nubus graphics card from eBay and we'll see what happens when I plug it in.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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rubber_jonnie
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Re: The daemon Mac IIci: Can it be fixed?

Post by rubber_jonnie »

stephen_usher wrote: 17 May 2023 09:06 Now that I've disconnected the video cable and moved the memory into bank B, which isn't accessible by the on-board video sub-system, and warmed the RBV chip with my hand for about a minute then it will reliably bong and stop predictably, probably at the point where it scans for a video card.

So, "reliably" for certain values of reliable.

I've ordered a Nubus graphics card from eBay and we'll see what happens when I plug it in.
Be interesting to see how the NuBus card pans out.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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stephen_usher
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Re: The daemon Mac IIci: Can it be fixed?

Post by stephen_usher »

The Nubus graphics card is due to be delivered to work tomorrow. However, I won't be able to collect it until Sunday as I have to drive down to Cornwall tonight for a meeting with solicitors tomorrow to start the probate for my Dad's estate.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
User avatar
rubber_jonnie
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Posts: 14888
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Location: Essex

Re: The daemon Mac IIci: Can it be fixed?

Post by rubber_jonnie »

stephen_usher wrote: 18 May 2023 15:19 The Nubus graphics card is due to be delivered to work tomorrow. However, I won't be able to collect it until Sunday as I have to drive down to Cornwall tonight for a meeting with solicitors tomorrow to start the probate for my Dad's estate.
From our recent experiences, it wasn't the smoothest of processes, and not what you need when you're grieving. I hope the process goes more smoothly for you than it did for us.

Thankfully we are at the end of the road now, but the whole thing was very trying. Good luck.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...

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