128k ram replacement.

1000 chips? Are you nuts? Trying to corner the market? lol

So how much for a re-chip?

lol no the seller told me free shipping if i bought one more lot of 500 so i couldn't resist.

Yeah I tell you What changing the ram in these Macintosh 128k not what i would call easy at all.

Mcdermd must go to his happy place when he does these… he makes it sound like, it's as easy as changing your underware

It is easy. I think what you mean is that it is tedious. I like to spread it across two work sessions.

It's only 256 pins to desolder and resolder, how much could... no, wait, that is a pain in the arse. I suck enough at soldering I need to take a break and go breathe into a paper bag for a while after doing one IC.

Silly question: Are you putting in sockets, or just soldering the chips down? Obviously sockets wouldn't be original, but they're totally worth it in every other way.

In a restoration, I put down chips.

oh … no sockets…

but the mcdermd way is to solder them down right to the main board

i've been trying to emulate his work… witch i am finding is very difficult…

I re-ram'd (2) 128 boards last night… they both work too!! one was for me, and one was for a customer.

I didn't get to bed till 6am… I am like a walking zombie today.

I think, I need to crank up the temp on my iron… but i'm already at 750F

Seems like the solder is not really flowing into the through holes as well as i like.

these (2) 128 boards i did, had some slight surface corrosion on the soldered joints.. I am sure that doesn't help things!

I suppose a Mac 128k is pretty much a paperweight when it comes to usefulness, so I suppose authenticity is the way to go.

(Every time I yank something out of one of my toys a socket goes in, which I suppose dings the collector value, but the last thing I want to have to go through desoldering the same part again later. Unless you're actually going to the extreme of tracking down exact replacement parts with appropriate date codes it's still going to show as a "repair" anyway, but, yeah, I suppose it makes the difference between the unit being a "20 footer" vs. "a driver" in car collecting terms.)

I agree, if they tell me to put sockets i will. customer is always right

Whenever I change oscillators I use sockets

That's a pretty hot iron, uni. I don't usually have to exceed 625F unless it's ROHS on a ground layer.

That's a pretty hot iron, uni. I don't usually have to exceed 625F unless it's ROHS on a ground layer.

Click to expand...

Ditto.

I wonder how a heat gun would work on this board. Its a lot of heat targeted for a long time. But my though it to have the board upside down and see if the chips will fall out. Maybe attached some weight via putty or something.

lol it says 750F… can't say that is what its acutely at… as i said it feels like it needs more heat.

I ordered an IR Temp gun.. When it comes in i'll be able to see how hot it really is.

DT-812

-50°C to 500°C

-58°F to 932°F

http://smart-prototyping.com/Prototyping-Equipment/General-Lab-Equipment/IR-Thermometer/IR-Thermometer-CEM-DT-81X---50-degree-to-500-degree-.html

I should have enough ram to last me a little while.

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:lol:

Ditto.
I wonder how a heat gun would work on this board. Its a lot of heat targeted for a long time. But my though it to have the board upside down and see if the chips will fall out. Maybe attached some weight via putty or something.

Click to expand...

Yeah the chips are not gonna fall out. The legs are all bent over…

and really it would not help me much if they did fall out, because each hole still have to be solder sucked anyways.

I am too cheap to afford a hakko. So what I do is clip out all the chips, pull all the pins, and use a VERY tiny drill bit and drill in the center of each hole, avoiding the Via plating. That works for me. lol.

This is assuming solder braid fails for me.

Oi! Even without a Hakko, I did a 128k board with a Big Blue Soldapullt Sucker