Anyone up for some IIcx troubleshooting assistance? We have clocks but no activity...

[Sideburn]

I'd put my effort into working out why it won't chime with a NuBus card installed first. I suspect it might sadmac with no video card anyway, so that doesn't tell us anything.

It is sad Mac’ing with:

No cards installed at all.
Radius video card (and no life on the monitor)

It is NOT Sad Mac’ing (no signs of life) with:

Apple Macintosh II video card
Supermac video spigot card
Radius Rocket card

 

[Sideburn]

Again, the RAM contacts and RAM slots, not the board.

I know. To clarify, I scrubbed SIMM sockets with alchohol and a toothbrush (as well as the entire board).

 

[Phipli]

It is sad Mac’ing with:

No cards installed at all.
Radius video card (and no life on the monitor)

It is NOT Sad Mac’ing (no signs of life) with:

Apple Macintosh II video card
Supermac video spigot card
Radius Rocket card

Don't put a rocket in this computer until it works. Don't risk a $300 to $400 card!

 

[Phipli]

scrubbed SIMM sockets with alchohol and a toothbrush

I don't recommend using a brush on SIMM sockets, it can catch and bend the pins, depending on the socket style. Not to bad on this style, but I still wouldn't.

 

[Sideburn]

I don’t think it is the SIMMS or the sockets. I’ve cleaned them and tried multiple sets in multiple combinations but it could be ram related from a bad trace or back supporting / glue chip for sure. But I will double check and clean the simms and sockets to make sure.

 

[Sideburn]

Don't put a rocket in this computer until it works. Don't risk a $300 to $400 card!

Wow! Really? I had no idea. It’s my card from 1992 and it’s also loaded in ram

 

[Sideburn]

I don't recommend using a brush on SIMM sockets, it can catch and bend the pins, depending on the socket style. Not too bad on this style, but I still wouldn't.

Ah ok good to know

 

[Phipli]

I don’t think it is the SIMMS or the sockets. I’ve cleaned them and tried multiple sets in multiple combinations but it could be ram related from a bad trace or back supporting / glue chip for sure. But I will double check and clean the simms and sockets to make sure.

Yup, agreed, but... it is such a common issue that it is one less thing to worry about.

I'd fix the power circuit so I didn't have to faff, then search for breaks, shorts and bad buffer chips in the nubus circuit.

 

[Phipli]

fix the power circuit so I didn't have to faff

Start near the 74_132 chips.

 

[Sideburn]

That’s why I’m trying to get frkn’ IICX back! The first one that I started this thread with is my original computer from early 90s it’s loaded with a video capture card, a radius rocket with i think 40 megs of RAM that would have cost thousands back then but I worked for Kingston Memory at the time and there was ram flowing around everywhere. My original hard drive is in it with all my crap on it! I’m anxious to see if I can get it all back up and running again.

 

[Sideburn]

Yup, agreed, but... it is such a common issue that it is one less thing to worry about.

I'd fix the power circuit so I didn't have to faff, then search for breaks, shorts and bad buffer chips in the nubus circuit.

Yeah I’m going to address the power situation next. Rule that out.

 

[Phipli]

That’s why I’m trying to get frkn’ IICX back! The first one that I started this thread with is my original computer from early 90s it’s loaded with a video capture card, a radius rocket with i think 40 mega of RAM that would have cost thousands back then but I worked for Kingston Memory at the time and there was ram flowing around everywhere. My original hard drive is in it with all my crap on it! I’m anxious to see if I can get it all back up and running again.

If you go to bigmessofwire's meetup, someone will probably backup the disk for you? If you're in the right part of the world?

https://68kmla.org/bb/index.php?threads/san-francisco-bay-area-mini-meetup-expo-and-swap-meet.45075/

 

[Sideburn]

If you go to bigmessofwire's meetup, someone will probably backup the disk for you? If you're in the right part of the world?

https://68kmla.org/bb/index.php?threads/san-francisco-bay-area-mini-meetup-expo-and-swap-meet.45075/

Ah cool yeah I need to go to some of these. Like VCF etc also want to check the computer history museum out there. I am in San Diego.

I’m have a feeling the bulk of my content was on a full height 2GB hard drive that’s long gone. The internal drive probably only has the OS and all the apps I’m afraid.

 

[Sideburn]

Does a Mac plus have the same SIMMs? I have a working one of those.

 

[Phipli]

Ah cool yeah I need to go to some of these. Like VCF etc also want to check the computer history museum out there. I am in San Diego.

Practically next door... alphabetically.

I’m have a feeling the bulk of my content was on a full height 2GB hard drive that’s long gone. The internal drive probably only has the OS and all the apps I’m afraid.

Apps are often the interesting part

I've never owned a full height disk. I have a 5.25" disk. Takes ages to spin down.

Does a Mac plus have the same SIMMs? I have a working one of those.

Plus SIMMs work in a IIcx.

 

[Sideburn]

Ok great then I can test them all and have some known good ones. I’ll report back. Thank you very much for helping.

 

[Sideburn]

It's looking like something is starving the PSU. The modern ATX must be able to handle the load but on the stock PSU the voltage to pin 9 (power on) and 5v rail is dropping to 1.9v and the 12v rail is dropping to about 7. I am suspecting it might be something on the 12v rail. Im going to make a molex cable to run to the stock PSU with plugs on them so i can disconnect the 12v rail or put an amp meter inline to check the load.

 

[Phipli]

It's looking like something is starving the PSU. The modern ATX must be able to handle the load but on the stock PSU the voltage to pin 9 (power on) and 5v rail is dropping to 1.9v and the 12v rail is dropping to about 7. I am suspecting it might be something on the 12v rail. Im going to make a molex cable to run to the stock PSU with plugs on them so i can disconnect the 12v rail or put an amp meter inline to check the load.

It could be just the PSU failing?

Those particular PSUs are failing constantly. My dad and I have 4 working out of about 9.

 

[Sideburn]

It could be just the PSU failing?

Those particular PSUs are failing constantly. My dad and I have 4 working out of about 9.

This is odd. With ATX supply connected I have a solid 12v off L10 and pin 12 of the sound chips. And solid 5v on all of the logic. And sad Mac chime.

Stock PSU get starved. Could plow the stock PSU but when I kick it on without the PCB load it powers up, fan spins and I get 12 and 5v. It also soft powers on when connected to my original PCB. But it only had a clock so it wasn’t pulling much load either.

 

[Phipli]

but when I kick it on without the PCB load it powers up, fan spins and I get 12 and 5v.

That doesn't meant anything.

Unloaded can produce bad voltages from a good PSU and good voltages from a bad PSU.