Macintosh Plus 1MB Won't boot Help/Guidance?

[RubyRoo]

HUZZAH PROGRESS. okay now i'll go to bed before i fuck things up ahaha

 

[68kPlus]

Raster too bright, need to turn down the variable resistor. Let me know how it goes!

 

[joshc]

Already ahead of you! looked up a youtube video just to double check. There were some traces on the Analog board that were kind of sketchy. View attachment 68828 View attachment 68829

So i soldered some wires between them. continuity seems fine. Wish i was better at soldering but it looks okay! i think. maybe it's shit i don't really know ahaha

I don’t think those bodge wires are safe. You really shouldn’t be using anything fabric insulated in there. And the twisted wire stuff may not be suitable either depending on the current running through those traces.

Try some flux on your joints, those are really blobby.

 

[68kPlus]

I don’t think those bodge wires are safe. You really shouldn’t be using anything fabric insulated in there. And the twisted wire stuff may not be suitable either - bear in mind how thick the original traces are and the reason for that. There’s high voltages running through these boards.

Try some flux on your joints, those are really blobby.

If you don't have flux handy, Vaseline works well too, found this out as I didn't have any for my iMac flyback repair job

 

[Phipli]

If you don't have flux handy, Vaseline works well too, found this out as I didn't have any for my iMac flyback repair job

Hum...

I wouldn't use vaseline, a flamable petrochemical, as a substitute for an acid cleaning product, especially on high voltage circuits. They're completely and utterly different things.

The best thing to use as flux is flux. The 'no clean' stuff is the best choice since it reduces the chance of future issues.

 

[joshc]

Isn’t Vaseline flammable?

 

[joshc]

Hum...

I wouldn't use vaseline, a flamable petrochemical, as a substitute for an acid cleaning product, especially on high voltage circuits. They're completely and utterly different things.

The best thing to use as flux is flux. The 'no clean' stuff is the best choice since it reduces the chance of future issues.

Beat me to it

 

[Phipli]

Isn’t Vaseline flammable?

Yes. Yes it is. It is like, an emulsified petrol.

Edit - emulsion is the wrong word, I'm struggling to think of the right term for "thickened".

Double checking, it is effectively a thick paraffin, like halfway between a candle and the fuel you use in oil lamps.

Don't put it on circuit boards.

 

[RubyRoo]

So i'm ASSUMING the screen is suppose to be grey like on the right side. however those slanted lines won't disappear. I did turn down the cutoff and brightness trying to get a 'fine' balance between the two with ill luck. However i did adjust the width and height and made it more appropriate which i'm quite happy about. the grey lines aren't the WORST thing in the world but would be nice to know what's the deal with em.
As for the wires. Yeah i know... They're not the best, I did clean it up post picture though it's very unlikely anything i'll do would qualify as impressive

The type of wire that i use is the one i most prominently use in pinball machines. Those traces and wires are only connected to the battery socket in the back of the Macintosh that store the date and time and stuff for when it's unplugged. The traces have continuity between them and the wires are tightly on the circuit board so. Yes i'll change them out. No it probably won't be today though.

 

[RubyRoo]

Just for reference. the scan lines only disappear when the background is black. with the floppy in the centre. like the first picture.

 

[Phipli]

View attachment 68841View attachment 68842
So i'm ASSUMING the screen is suppose to be grey like on the right side. however those slanted lines won't disappear. I did turn down the cutoff and brightness trying to get a 'fine' balance between the two with ill luck. However i did adjust the width and height and made it more appropriate which i'm quite happy about. the grey lines aren't the WORST thing in the world but would be nice to know what's the deal with em.
As for the wires. Yeah i know... They're not the best, I did clean it up post picture though it's very unlikely anything i'll do would qualify as impressive

The type of wire that i use is the one i most prominently use in pinball machines. Those traces and wires are only connected to the battery socket in the back of the Macintosh that store the date and time and stuff for when it's unplugged. The traces have continuity between them and the wires are tightly on the circuit board so. Yes i'll change them out. No it probably won't be today though.

I can't tell what the square in the middle is, but it kind of looks like that background is meant to be black. Is it every second pixel? Or is it an... analogue / uniform grey?

What does the square in the middle look like?

 

[RubyRoo]

I can't tell what the square in the middle is, but it kind of looks like that background is meant to be black. Is it every second pixel? Or is it an... analogue / uniform grey?

What does the square in the middle look like?

Floppy disk icon with the ?. It's not blinking but the floppy disk drive isn't plugged in. It blinks and works when it's plugged in though. Background is black and when the mouse is plugged in and i move it around a bunch of white dots appear on the screen and go nuts when it's moved around

 

[RubyRoo]

Here's a video of me moving the macintosh mouse around while it's in the 'waiting for floppy disk' screen. When the mouse isn't moved a white dot still goes from top to bottom. it wasn't as noticeable before but now that i messed with the cutoff it's alot more present.
View attachment IMG_3364.mov

 

[Phipli]

Here's a video of me moving the macintosh mouse around while it's in the 'waiting for floppy disk' screen. When the mouse isn't moved a white dot still goes from top to bottom. it wasn't as noticeable before but now that i messed with the cutoff it's alot more present.
View attachment 68843

Is there any battery damage anywhere else? On the logic board?

It's looking like you have more work to do. It's all fixable. The only things that aren't fairly easy to replace are the tube, flyback and the custom programmed logic chips, all of which seem to be good in yours.

I start by fixing any visible damage, in your case that would be the battery damage.

Someone is probably about to jump in and start talking about capacitors, for now, ignore them. The caps are pretty reliable in the Plus. It is something to come back to later if there is an issue, and replace on condition.

 

[RubyRoo]

Is there any battery damage anywhere else? On the logic board?

It's looking like you have more work to do. It's all fixable. The only things that aren't fairly easy to replace are the tube, flyback and the custom programmed logic chips, all of which seem to be good in yours.

I start by fixing any visible damage, in your case that would be the battery damage.

Someone is probably about to jump in and start talking about capacitors, for now, ignore them. The caps are pretty reliable in the Plus. It is something to come back to later if there is an issue, and replace on condition.

So circuitry isn't my strong suit but based on what i can personally view of the machine. I would say no. it seemed like those traces in particular were the worst of the analog board. If you give me just a few moments here i'll discharge the CRT and the board and inspect it.

 

[Phipli]

So circuitry isn't my strong suit but based on what i can personally view of the machine. I would say no. it seemed like those traces in particular were the worst of the analog board. If you give me just a few moments here i'll discharge the CRT and the board and inspect it.

I'd look at the logic board too. Under where the battery was.

 

[mg.man]

Under where the battery was.

Um... the battery is external to the logic board on a Plus.

 

[Phipli]

Um... the battery is external to the logic board on a Plus.

I know, but it can run around the lower terminal, down the analogue board, on to the chassis, and onto the logic board?

I'm assuming that it might have happened because it looks like a black screen with a floppy icon, which feels like a logic board rather than analogue board issue.

 

[RubyRoo]

I'd look at the logic board too. Under where the battery was.

The battery (to my awareness) isn't anywhere near the logic board. however i did take the logic board out and am now inspecting it thoroughly. Nothing seems out of the blue except for this

This leg to the M/C 8850L chip (labeled as 'filter' on the board) is soldered and or pressed up against this other joint. where as on the other 8850L chip. it is not. i'm not sure if this would do it but is it possible?

My god was the logic board ungodly amounts filthy. i should've put it into the dishwasher! ahaha

 

[joshc]

I know, but it can run around the lower terminal, down the case, on to the chassis, and onto the logic board?

That’s not common though. Something else has caused the bit of corrosion on the analog board traces. Probably storage conditions at some point.