Corroded Chip

[Iamanamma]

This is the inside of a Mac IIci.  This chip is corroded.  I don't know what this chip is, or what it does.  Can someone enlighten me?

 

[IlikeTech]

That looks more like sticker residue or dirt to me, because the pins are all still shiny.  That's the CPU, so if it's bad, things really won't work.

I would try wiping that off with some rubbing alcohol on a paper towel.

 

[cheesestraws]

I don't know what this chip is, or what it does

The one labelled MC68030?  That's the CPU.

 

[Iamanamma]

Thank you.  I had a talent for swapping out hard drives, so now it is my job to try to fix all of the computers when things go wrong.  As you can tell, I don't really know as much as I need to know to do this.  This IIci is acting a little odd.  I have a different one that is all clean and shiny that may get swapped out, but now I know something now that I didn't know before.

 

[Iamanamma]

Is the little chunk missing out of the top side normal?  I hate pulling the power supplies, so I really don't want to yank it out of the other so I can see the CPU.

 

[tattar8]

Yes, that notch is there to mark Pin 1.

 

[Iamanamma]

Yes, that notch is there to mark Pin 1.

Okay great.  Thanks!

 

[cheesestraws]

This IIci is acting a little odd

I stand to be corrected here, but if the CPU were noticeably damaged, I'd expect rather worse than 'acting a little odd'

 

[Iamanamma]

I stand to be corrected here, but if the CPU were noticeably damaged, I'd expect rather worse than 'acting a little odd'

Okay, you are much more experienced than I, so I believe you.  I am going to be checking for software issues.  It had a SCSI2SD installed in it, but I didn't do the install.  I am wondering if something semi important was missed when the OS and PAC software were installed.  I just saw that gunky chip when I had to pull the power supply to get at the floppy drive, and figured asking questions was not a bad idea.

 

[cheesestraws]

asking questions was not a bad idea

asking questions is almost never a bad idea, especially when you want to know about systems you're relying on .  I didn't mean to sound at all dismissive, so I hope I didn't — perhaps more I should have said "I would be surprised if 'acting a little odd' was a result of CPU damage, but I wouldn't absolutely rule it out'.

 

[Iamanamma]

asking questions is almost never a bad idea, especially when you want to know about systems you're relying on .  I didn't mean to sound at all dismissive, so I hope I didn't — perhaps more I should have said "I would be surprised if 'acting a little odd' was a result of CPU damage, but I wouldn't absolutely rule it out'.

No, you weren't sounding dismissive.  There have been times others have made me feel like an object of ridicule because of my vast lack of knowledge, but for the most part, people on these forums have been very kind.  I can't say that you guys don't go way over my head often, but there are always folks who are patient enough with me to simplify it enough that I can usually figure it out.  And when we do that, I learn.

 

[Papichulo]

The capacitor next to it is leaking badly

 

[PotatoFi]

Yeah... and leaky capacitors certainly will cause problems. All machines of this age are due for new capacitors.

 

[PB145B]

It looks to me like those caps have already been replaced and that is flux.  

 

[LaPorta]

We’re a pretty friendly forum, no question is dumb. Capacitor change as suggested would be your first step towards figuring it out.

 

[tattar8]

When you say it's behaving weird, what exactly does that mean?  You get signs of life out of it but it behaves erratically?  If you even get a chime (either kind) out of it I'd think that eliminates the CPU as being the problem.

I have a IIci with what I believe to be a dead 68030, and that's because it does nothing at all after poweron -- no chime, nothing on the address lines, etc, even with a good system clock.

 

[Mr SN]

have a IIci with what I believe to be a dead 68030, and that's because it does nothing at all after poweron -- no chime, nothing on the address lines, etc, even with a good system clock.

Make sure you have the jumper on for the ROM select..  This is exactly what happens when that jumper is missing.

 

[Iamanamma]

It looks to me like those caps have already been replaced and that is flux.  

Yes.  The capacitors have all been replaced.  We went through our inventory of all of our IIsi and IIci units and had the capacitors replaced.

 

[Iamanamma]

When you say it's behaving weird, what exactly does that mean?  You get signs of life out of it but it behaves erratically?  If you even get a chime (either kind) out of it I'd think that eliminates the CPU as being the problem.

It powers on and boots up normally, but it is not communicating correctly with the machine it is connected to by a pair of dongles.  It has a SCSI2SD replacing its HDD.  To be honest, my bet is that something in the PAC software isn't quite right because EVERYTHING else works correctly.  Also, when we replaced the IIci with a backup unit we have that contains a conventional HDD, the odd behavior disappears.  I have 2 of these machines that use a Mac IIsi as their brain, and those are both using SCSI2SD instead of HDD. SInce the IIsi units are running flawlessly, I am thinking there is something not quite right with the software on the IIci.  I just saw that gunky chip when I pulled the power supply so I could get at the dirty gunky floppy drive to put a clean one in.  I am SO not sticking my "hard to replace" floppies into a dirty drive.