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Macintosh Plus boot problems

HarryWorksInc said:
I found one on ebay "RAM TMS4164-15NL TI 16-Pin DIP", I paid for it and it will be here between the 19th - 20th so I will get back to you when or if I get it working...
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Excellent. Remember that the chip must be orientated the right way around.

Ironically, having unskewed your image, I've noticed that a RAM chip at "G6" has already been replaced with a Texas Instruments TMS4164. :cool:

I've circled where the new chip should go (based on the error code referring to location "F12").

Once again, good luck! :)
 

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Actually my image on page one does not have that RAM chip replaced... I don't know how you got that picture.

But thanks, I do know enough about circuit board cunstruction to put it in the right way ;)
 
HarryWorksInc said:
Actually my image on page one does not have that RAM chip replaced... I don't know how you got that picture.

But thanks, I do know enough about circuit board cunstruction to put it in the right way ;)
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No probs, but look/read again. The RAM chip at G6 has been replaced already (by Apple, no doubt). The chip I circled is the one you need to replace (yes I took the liberty of pasting a TMS4164 over the top of the circled chip F12). But it's your pic, just -unskewed. :)
 
Hey, I just got the chip in the mail this morning, and I decided to do it myself. I worked on getting the first chip out for 3 hours, and then I put the new one in started it up and it worked! I was so amazed and happy! It had the disk question mark symbol as usual and the mouse worked fine. But when I put the floppy disk In the drive didn't start doing anything. So I turned the computer of and wiggled the plug to the floppy drive a little and pushed it in on both side to make sure that both connections were fine, I turned the computer on and there was a resounding SCREEECH and then smoke came out of the pcu! I have a new analog power board in the mail (Ebay) along with a floppy drive. But does anyone know why this happened?
 
Maybe the electrolytic caps dried out. IIRC the flyback circuit was also known to be somewhat short-lived, as there was a going market for Mac Plus flyback transformers in the day.

A floppy drive unused in that long is probably mechanically troubled. Could be anything. Old floppy drives I've pulled out of storage often have congealed grease or accumulated dust on parts that should slide effortlessly.

I wouldn't count on the floppies retaining their magnetic signal that long, either. It depends on how they've been stored. Humidity, stray magnetic fields, it all adds up.
 
Ok, so then I should get a new floppy drive too. But where would I get a new flyback circuit?
 
HarryWorksInc said:
Hey, I just got the chip in the mail this morning, and I decided to do it myself. I worked on getting the first chip out for 3 hours, and then I put the new one in started it up and it worked! I was so amazed and happy! It had the disk question mark symbol as usual and the mouse worked fine. But when I put the floppy disk In the drive didn't start doing anything. So I turned the computer of and wiggled the plug to the floppy drive a little and pushed it in on both side to make sure that both connections were fine, I turned the computer on and there was a resounding SCREEECH and then smoke came out of the pcu! I have a new analog power board in the mail (Ebay) along with a floppy drive. But does anyone know why this happened?
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Oh dear. Rotten luck. Glad to hear the RAM chip replacement worked. But where did the smoke come from? Do you know where? If possible, take a photo of the top section of the analog board.

There are two silver heat-sinks on the top edge. If one is a blue-purple color, then the Flyback transformer is definitely shorted.

It's usually possible to clean and re-lubricate the floppy drive. The floppy drives do have a tendency to lose the felt that places gentle pressure on the disk read surface above the head.

Other issues might be bent pins on the floppy drive connectors.

Whilst it's a terrible coincidence that the flyback transformer has shorted, and they are/were a common problem with the analog board, a part of me is wondering if something else shorted as a result of an accident. I'm not trying to be accusatory, just trying to help, you understand.

One thing I did myself was to accidentally hit the circuit board of the tube neck on a MacSE. It cracked the tip of the tube and caused a horrible squeal when I next powered it up. Luckily, I had a spare tube and was able to repair the analog board.
 
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I decided to limit the variables to what went wrong and I took out my old SE, I tries out the floppies and they worked fine, so that means that the floppy drive and the analog power board have to. Be replaced for sure. My replacement analog bored should be here tomorrow or wensday.

After all this I really want to get this to work, when I tested the floppies on my SE I found one of my college essay! This brings back memories.
 
HarryWorksInc said:
I decided to limit the variables to what went wrong and I took out my old SE, I tries out the floppies and they worked fine, so that means that the floppy drive and the analog power board have to. Be replaced for sure. My replacement analog bored should be here tomorrow or wensday.

After all this I really want to get this to work, when I tested the floppies on my SE I found one of my college essay! This brings back memories.
Click to expand...

Here is a good description and photos of the 400K floppy drive and how to deal with some of it's problems:

http://lisafaq.sunder.net/lisafaq-hw-floppy_lube.html
 
Cool I have a new floppy drive on the way, out of curiosity if I got a program online that was correctly formatted from one of the many online directories of old Mac programs can just put it on any old disk and use any old floppy drive burner? Or do I have to go out and buy a special versions of these?
 
HarryWorksInc said:
Cool I have a new floppy drive on the way, out of curiosity if I got a program online that was correctly formatted from one of the many online directories of old Mac programs can just put it on any old disk and use any old floppy drive burner? Or do I have to go out and buy a special versions of these?
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No. you can't. The Mac 128 and original 512K ( not 512KE) are single sided drives at 400K. Later drives were double sided at 800K. Even later drives became higher density at 1.44MB

You should be able to reformat and floppy disk in a 400K drive (despite what some say), but unless your disk copy software can forcibly write a 400K disk in a later drive, you're sunk.

When you get the new drive, make sure the felt (as noted in the floppy drive page I linked to) is in place or you'll scratch the floppy disk media.
 
Ok... you lost me a little, do I need special software to reformat a disk? Also I really just want to run these programs on my SE so is it easier to reformat a disk to 800k?
 
HarryWorksInc said:
I will be using Mac OSX 10.6 on my MacBook Pro
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Then no. That makes it impossible. USB floppy drives can only write 1.44MB floppy disks.

Best option is a later Mac with an ethernet port running system 7.x.x. 7.5.x or 7.6.x will be best.

Anything later than system 7 is going to be unable to write a 400K floppy and without ethernet, getting the data to it will be extremely difficult.
 
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