II+ Worth Saving?

[MaxHeap]

I've starting cleaning the rust from this, but wanted to see if it was a lost cause or if anyone else has run into something similar. It speaker just buzzes and there are some lines on the screen when I turned it on. The capacitors need to be changed also, but thats not a big deal.

Also, are there places for parts for II's that arent too crazy on price?

 

[MacTech68]

Wow, that is in a pretty sad shape.

Things like this are fixable, but require soldering skills, possibly a number of parts (some rare) and plenty of patience.

If you like the joy from tedious fiddly work when it all goes well at the end, then go right ahead.

It's your call, but it would certainly be a labor of love.

 

[MaxHeap]

Wow, that is in a pretty sad shape.

Things like this are fixable, but require soldering skills, possibly a number of parts (some rare) and plenty of patience.

If you like the joy from tedious fiddly work when it all goes well at the end, then go right ahead.

It's your call, but it would certainly be a labor of love.

So I started cleaning this one up. I could only save one bank of ram chips, but when I start it up with one bank (the one closest to the keyboard), I get no beep and a screen full of question marks. Do I need all sockets filled with ram or is this a sign of something else being wrong?

 

[tevion5]

So I started cleaning this one up. I could only save one bank of ram chips, but when I start it up with one bank (the one closest to the keyboard), I get no beep and a screen full of question marks. Do I need all sockets filled with ram or is this a sign of something else being wrong?

That looks like the tile board of some sadistic game show.

 

[MacTech68]

The only reference I can find for all '??????' on the screen is to check the 74LS153 at location E11.

There's actually three of these. E11, E12 and E13. You could try swapping them to see if the fault changes, or pay special attention to those ICs & sockets.

As for needing to be full populated with RAM, I can't recall and am unable to find a reference for that.

 

[David Schmidt]

As for needing to be full populated with RAM, I can't recall and am unable to find a reference for that.

You only need the very bottom 4k, really... zero page, stack, keyboard buffer, text RAM, etc. is all down there.

 

[MaxHeap]

The only reference I can find for all '??????' on the screen is to check the 74LS153 at location E11.

There's actually three of these. E11, E12 and E13. You could try swapping them to see if the fault changes, or pay special attention to those ICs & sockets.

As for needing to be full populated with RAM, I can't recall and am unable to find a reference for that.

One was kinda dirty. I cleaned it up (cleaned all 3) and it didn't change anything. Didn't swap them around, as I was thinking it was memory related. Wonder if I should just swap around the memory chips? I really want to save this thing.

 

[tdiaz]

Swap RAM around 4 at a time, concentrate on the 1st row only.

Of course, you are banking on the RAM being the only problem at that point. The best way would be if you had some way of independently verifying the DRAM functionality, so that placing known 'good' RAM in that should either make it work, or allow you to move on to other problems.

 

[MaxHeap]

Swap RAM around 4 at a time, concentrate on the 1st row only.

Of course, you are banking on the RAM being the only problem at that point. The best way would be if you had some way of independently verifying the DRAM functionality, so that placing known 'good' RAM in that should either make it work, or allow you to move on to other problems.

After playing around with RAM in different sockets, IT BOOTS!! I was able to get to the basic prompt and run a small program. I'm amazed I was able to salvage this thing. I'm going to order new RAM for the rest of the banks and cross my fingers that nothing else is wrong. Thanks everyone for the help!

 

[MacTech68]

Wow. That is good news indeed - considering how bad it looked.

Well done!