Brett's STE - Repair thread

[sporniket]

Great news :)

[BrettRogersUK]

Hiya Matey,

I've only just had chance to check on this.

WOW, What miracles have you performed?? That looks great. Hopefully when you check or replace the CPU socket it'll work flawlessly.

What an amazing job you've done! Well done mate!

Kindest Regards,

Brett

[rubber_jonnie]

Hiya Matey,

I've only just had chance to check on this.

WOW, What miracles have you performed?? That looks great. Hopefully when you check or replace the CPU socket it'll work flawlessly.

What an amazing job you've done! Well done mate!

Kindest Regards,

Brett

Hey Brett. There was a spot of luck, but mostly a LOT of tracing from every single pin on the sockets to the endpoints and buzzing out to make sure of connections to every single point on the rest of the board were good. In fact, that was the large part of what I did today.

The good news is that I reflowed the CPU socket and tweaked the metal 'fingers' and I seem to have it running stably now :)

Big guns came out earlier too:

IMG_20220130_230358.jpg

What you have here is the full diag cart and test harness combo. Combined they test all the major ports, so Midi, ACSI, Parallel, Serial, keyboard and joystick ports. It doesn't test the enhanced joystick ports as there is no loopback adapter for them, but the good news is that everything else passed!

I did swap out the Gotek for a real floppy drive and all the FDD tests passed too :)

There is one weird thing though. It doesn't seem to work with TOS 1.62 properly.

Let me clarify. It boots fine with your old ROMs and the dual TOS shifter set to TOS 1.62. But, when you start to move the mouse, the left click doesn't work and then it eventually freezes.

If you switch to TOS 2.06 it works just fine, so that's a bit of a puzzler.

Plus, the rest of the diagnostics, keyboard included & mouse work just fine, so I can't say there is any really obvious problem with the machine going by the diag carts, even with either TOS version installed.

I did try 2 different keyboards, so nothing there. Something to think about, but ultimately you'll probably only really need TOS 2.06.

I have a bit of a busy week, as I need to head up to my parents to sort some stuff out in the week, so might not be able to fully wrap up, and I need to think some more on the TOS 1.62 thing, but I will write up a bit of a summary explaining just what troubleshooting methods I used to get to this point.

Pheew, that was fun :)

[rubber_jonnie]

Great news :)

I have to say that your schematics were absolutely invaluable in getting this machine running, thanks so much for doing them, they allowed me to isolate the top and bottom layers and trace every single pin of the ROM sockets to every single last endpoint on the board. It'd have taken a lot longer without, and about the only thing I needed to reference the old schematics for was the DIP DMA IC not present in your drawing.

I was so useful having them, thanks for taking the time to produce them :)

[exxos]

Just a wild guess.. I don't remember if 1.62 / 2.06 defaults with the blitter on or off ... Might be worth saving desktop with both versions with blitter disabled just to see if that makes any odds or not..

[rubber_jonnie]

Just a wild guess.. I don't remember if 1.62 / 2.06 defaults with the blitter on or off ... Might be worth saving desktop with both versions with blitter disabled just to see if that makes any odds or not..

Good idea, will see what I can do to test that, hopefully before I get away to my parents.

[BrettRogersUK]

There is one weird thing though. It doesn't seem to work with TOS 1.62 properly.

Let me clarify. It boots fine with your old ROMs and the dual TOS shifter set to TOS 1.62. But, when you start to move the mouse, the left click doesn't work and then it eventually freezes.

If you switch to TOS 2.06 it works just fine, so that's a bit of a puzzler.

Wow, I can't believe you've actually got it working again. I hope the thing with the TOS 1.62 can be bottomed out. If not no biggie I'll just use 2.06. But only when you've got some free time.

I hope it can be though. I love the classic 1.62 TOS. Just symbolic of my childhood really.

I hope you get your personal stuff sorted out. I'm in no rush to get this board back.

Regards

Brett

[sporniket]

Great news :)

I have to say that your schematics were absolutely invaluable in getting this machine running, thanks so much for doing them, they allowed me to isolate the top and bottom layers and trace every single pin of the ROM sockets to every single last endpoint on the board. It'd have taken a lot longer without, and about the only thing I needed to reference the old schematics for was the DIP DMA IC not present in your drawing.

I was so useful having them, thanks for taking the time to produce them :)

I am very happy that my works was so usefull :)

[rubber_jonnie]

I have to say that your schematics were absolutely invaluable in getting this machine running, thanks so much for doing them, they allowed me to isolate the top and bottom layers and trace every single pin of the ROM sockets to every single last endpoint on the board. It'd have taken a lot longer without, and about the only thing I needed to reference the old schematics for was the DIP DMA IC not present in your drawing.

I was so useful having them, thanks for taking the time to produce them :)

I am very happy that my works was so usefull :)

They certainly were, it'd have taken a lot longer without them :)

[rubber_jonnie]

Just a wild guess.. I don't remember if 1.62 / 2.06 defaults with the blitter on or off ... Might be worth saving desktop with both versions with blitter disabled just to see if that makes any odds or not..

Good call sir!!

I set up a disk on my own 1.62/2.06 machine and noted that the Blitter is on in 1.62 and off in 2.06 by default.

As soon as I turn the Blitter on it freezes in 2.06.

So I'm going to quickly test the Blitter in my Mega just to be sure it's good, and as long as it is, then it isn't a big jump to suspect the Blitter socket too, so I will tweak and reflow as I did with the CPU socket.