Help me get my "new" Apple IIgs working!

[R.Cade]

I would let it sit with vinegar for an hour or two. The vias are the weak spot with this in my experience. You can see where it got through to the other side of the board through one or more of them...

 

You can wash/scrub the whole board afterward in the kitchen sink with warm water, little dish soap, and a soft brush, then rinse well. I then usually wave it around a bit to "throw" the large amounts of water off, then go over it for a while with a hair dryer set to "warm". 

 

Makes them like new, and I've never had one damaged from the process. 

 

 

Edited April 12, 2020 by R.Cade

[+sixersfan105]

@Lee Adamson Have you undertaken repair session Part III yet? Enjoyed your first two videos!

[Lee Adamson]

Not yet, heh.  I had one too many beers and then spent a bunch of money on some new soldering tools to make it easier to work on all that surface mount stuff, as well as a desoldering gun, so I am kinda waiting until it gets here to continue.  Of course, Amazon is shipping super-slow due to the current insanity, so the stuff isn't supposed to be here until the middle of May.  ?

 

I been rearranging my workshop and fooling with a design to interface a raspberry pi to the ISA bus through an 8255 and give a DOSBox instance on the pi access to the real hardware in the host PC, in the meantime.  :3

[Lee Adamson]

Hey man.  You ever try that board and get your system working?

 

I'm stilllllllllll waiting on my new tools to get here.  Hot air gun finally shipped this morning.  Desoldering gun still hasn't shipped.  Grumble.

[Lee Adamson]

Desoldering gun finally shipped.....  Will be able to continue once it gets here.  A couple of DIP package chips have to come off, but most of all I think the slot 2 edge connector ought to be replaced too.  It's not near as bad as slot 1 was, but there is some significant corrosion down inside that will probably make it unreliable if I leave it.....

 

I guess I probably ought to get some magnet wire too.  The usual wire wrap wire for bodges may be too thick for some of the bus stuff.....  I guess we'll see how things go.

 

Sorry this is taking so long to get back to.  X_x

[+sixersfan105]

On 5/8/2020 at 9:15 PM, Lee Adamson said:

Hey man.  You ever try that board and get your system working?

Unfortunately, life got in the way (nothing bad, thankfully) and I haven't had the chance to clean up my IIgs case (want to sand off the rust from the power supply and shielding from the case before I pop in the ROM01 board) but once I do that, I'll put everything to use! I also need to clear out some inventory of retro video game systems from my game/computer room so that I can set up a table to have all of my Apple and Mac goodies ready for action (SE/30, Color Classic and IIgs). All in good time!

 

23 minutes ago, Lee Adamson said:

Desoldering gun finally shipped.....  Will be able to continue once it gets here.  A couple of DIP package chips have to come off, but most of all I think the slot 2 edge connector ought to be replaced too.  It's not near as bad as slot 1 was, but there is some significant corrosion down inside that will probably make it unreliable if I leave it.....

 

I guess I probably ought to get some magnet wire too.  The usual wire wrap wire for bodges may be too thick for some of the bus stuff.....  I guess we'll see how things go.

 

Sorry this is taking so long to get back to.  X_x

Nice, this is good to hear! You'll be able to get to repair Part III in no time.

[GameGeezer]

On 5/16/2020 at 12:33 AM, sixersfan105 said:

Unfortunately, life got in the way (nothing bad, thankfully) and I haven't had the chance to clean up my IIgs case (want to sand off the rust from the power supply and shielding from the case before I pop in the ROM01 board) but once I do that, I'll put everything to use! I also need to clear out some inventory of retro video game systems from my game/computer room so that I can set up a table to have all of my Apple and Mac goodies ready for action (SE/30, Color Classic and IIgs). All in good time!

 

Nice, this is good to hear! You'll be able to get to repair Part III in no time.

 

I use steel racking. Tables do not allow for enough machines in tiny rooms.

[Lee Adamson]

7 hours ago, GameGeezer said:

 

I use steel racking. Tables do not allow for enough machines in tiny rooms.

 

Yeah me too.  I just put up a couple new ones.  Those big 6'x2'x4' steel shelving units, I mean.  If you space the shelves right, you can use the bottom part for a desk and then still have a couple of storage shelves up above, though you waste a shelf or two doing it that way (I use the extra shelving arms to brace the thing on the sides and back, but I don't put the board in).

 

But I still don't have enough room, lol.  I do my antique computer stuff in the same workshop room where I do my antique gunsmithing, so I think I may have to clean out a storage room somewhere and split it up.  It's nice to have my two favorite things in the same place though.  It's like a concentration of happytime.

 

One thing I want to try at some point is to make a lazy susan type contraption for my corner desk.  I think I could probably put 3 or maybe even 4 machines on it, and then rotate it to the one I want to use and make some kind of detent to hold it in the right positions.  The cable routing would tricky though.  I'd have to route them down through the center, which would probably require some special hardware, and they might still get too twisted up eventually.  I figured I'd have the machines on the bottom, which would spin, and then have a stationary Commodore 1084 monitor (does NTSC composite, TTL RGB, and 15kHz analog RGB, in addition to having a built in speaker and audio amp, so will work with many machines) above, with some kind of homebrew selector that used a magnet and hall effect switches to automatically switch it to whichever computer was rotated to the front, and make the monitor select the right input.

 

Big plans.  Very little free time. 

 

Anyway, the desoldering iron was supposed to arrive yesterday, but it didn't.  Grumble.  I guess I shouldn't complain, though.

Edited May 17, 2020 by Lee Adamson

[GameGeezer]

23 hours ago, Lee Adamson said:

 

Yeah me too.  I just put up a couple new ones.  Those big 6'x2'x4' steel shelving units, I mean.  If you space the shelves right, you can use the bottom part for a desk and then still have a couple of storage shelves up above, though you waste a shelf or two doing it that way (I use the extra shelving arms to brace the thing on the sides and back, but I don't put the board in).

 

But I still don't have enough room, lol.  I do my antique computer stuff in the same workshop room where I do my antique gunsmithing, so I think I may have to clean out a storage room somewhere and split it up.  It's nice to have my two favorite things in the same place though.  It's like a concentration of happytime.

 

One thing I want to try at some point is to make a lazy susan type contraption for my corner desk.  I think I could probably put 3 or maybe even 4 machines on it, and then rotate it to the one I want to use and make some kind of detent to hold it in the right positions.  The cable routing would tricky though.  I'd have to route them down through the center, which would probably require some special hardware, and they might still get too twisted up eventually.  I figured I'd have the machines on the bottom, which would spin, and then have a stationary Commodore 1084 monitor (does NTSC composite, TTL RGB, and 15kHz analog RGB, in addition to having a built in speaker and audio amp, so will work with many machines) above, with some kind of homebrew selector that used a magnet and hall effect switches to automatically switch it to whichever computer was rotated to the front, and make the monitor select the right input.

 

Big plans.  Very little free time. 

 

Anyway, the desoldering iron was supposed to arrive yesterday, but it didn't.  Grumble.  I guess I shouldn't complain, though.

 

Be very gentle with it, once you have it, especially if it isn't calibrated tip temp control + vac. Note that cheaper irons are +/- 15% in temperature! That error margin makes it easy to ruin a board, especially if you have a medium wattage iron (longer touch duration) and analogue or inaccurate temp control. At the least, the models with the suction motor built in, or a hand pump (rubber ball) are what you want. The piston types tend not to like to pull all of the solder, so you end up overheating and burning traces, lifting pads, or worse.

 

I have seen a lot of botch obs come through where someone used a cheap desoldering iron and I had to turn the boards into a spaghetti mass of bodges. Believe it or not, solder wick (I have suggestions on that, as well, for anyone interested) tend to be my go to resource for connectors like that if they are in any way stubborn. 

 

Otherwise, I have a Weller WDS3000 with a WXD81. I have tried those piston type desoldering tools, and even Ihav liften pads with them. The act of heating, wiggling, and the way that the piston works can make it stupidly easy.

 

With hot air, likewise be careful. It is very easy to damage the component that you are pulling. PLCCs, we used to use suare chip-shape hot air tools that form-fit the PLCC size. Using hot air on any kind of plastic connector, is guaranteed to melt/warp the plastic. 

 

All in all, a pin-tip soldering pencil is better at ensuring a solid reflow without damage. Back when we were swapping ICs from a huge supply os spares, damaging the original chip wasn't meaningful. We would remove it, toss it, and solder in a replacement. Now that no spares exist, that isn't an option.

 

When I rebuilt that Datanetics board, I hand-desoldered every switch with solder wick, as I could not risk melting them, damaging connections, or damaging the PCBs. 

 

Practice with your new tools on something that you can sacrifice, that is of the same era (and thus uses the same solder mixture). You need to gauge out the correct temp settings and touch duration on something that you do not mind losing--remember that RoHS solder and old Pb/Sn solder have very different thermal properties!

 

Last, always go over each point that you plan to desolder with a flux pen, then use a normal iron to reflow it, before using the desoldering iron. This helps protect the board, and it helps to ensure that you can evenly melt the 30-year-old solder on the PCB with the desoldering iron. It will also make the joints cleaner when re-soldering the new component. Avoid using overly 'active' flux unless you plan to give the board a soak in flux remover. 

 

P.S. Ah, the goold old 1084/1084S. That was our common bench test monitor for a dozen platforms, plus if course a monstrocity from Toshiba and some other displays (PAL and NTSC, plus '50Hz NTSC for that bastard standard. 

 

I advise using the wood boards on the shelves. Two reasons for this: 

 

1. They prevent shorting naked components.

2. The reason they exist is to distribute weight and pressure across the shelf. Without them, eventually, the shelves tend to cave in the middle, until they collapse. 

 

My boards disintegrated years ago--these racks are 35-years old--and several of my shelves have caved. I expect that I rill pull them, take them out to the workshoppe, and weld in some metal braces. I likewise have a normal, chair-height platform all around the room, and then two decks above that, standing height and WTF height. In general, systems that I use most-regularly are at sitting height, less frequently, or with detatched KBs at standing height, and systems that I use only sparingly are at WTF height. 

 

I need to weld up a chair, at 'standing height' as my ancient back canna take the strain after a while, of standing up to use the systems for hours. 

 

I have full industrial racking in the storage room, with 8'x16'x4'-deep racking, and even some of the crossbeams for that have bowed. Those racks, I had to cut down to fit the ceiling. I've made outdoor buildings out of that stuff, 16' high, and welded metal siding to them. That makes a building with metal racking as walls, doubly useful. 

 

The hardest part for me, on those, is the concrete pour for the corners. 

Edited May 18, 2020 by GameGeezer