Bad Acorn Day

[rubber_jonnie]

Busy lunch break today...

I wonder how you manage to take your lunch while working on your machines...

I would rather call it a retro lunch.

:lol:

I have an hour so plenty of time to eat and retro 😁

[HigashiJun]

I have an hour so plenty of time to eat and retro 😁

Same here, but some repairs need more than 1 hour and I don't want to start something and resume it later.

[rubber_jonnie]

I have an hour so plenty of time to eat and retro 😁

Same here, but some repairs need more than 1 hour and I don't want to start something and resume it later.

I don't usually repair over lunch, but I like to build :)

[HigashiJun]

8-)

[rubber_jonnie]

So, I have decided that for the BBC B I need to leave installing the Sidewise board - for now. I don't want to add complexity whilst working on the FDD side of things, so it can wait.

I'll try and find some BBC disk images and hook up a Gotek next and see where that gets me.

As for the A5000, the PSU is definitely dead, as with a known good mains lead there is no output at all, which may explain the weird behaviour. I'll pull it and have a look on the bench, see what's what.

For now though, I'm just enjoying a nice cup of tea :)

[rubber_jonnie]

OK, so fun and games with the A5000. I tried to plug in the FDD power as I'd removed almost everything and the PSU sprang back to life, but the FDD power plug broke off and in the process and when it shifted it broke off the stepper motor connector!!!!

The solder looks awful!!!

IMG20241130105047.jpg

IMG20241130105104.jpg

IMG20241130105530.jpg

It's nothing I can't fix, but bloody annoying all the same.

Harumph!!!

[HigashiJun]

More repairs than expected...

[rubber_jonnie]

OK, A5000 FDD repaired and working:

IMG20241130143050.jpg

IMG20241130144252.jpg

IMG20241130144740.jpg

Bit of minor trace repair needed, the pads and traces at either end ripped up, but the machine boots fine and reads the FDD fine. Floppy disaster averted, just need to figure out what the main machine is up to now.

Time for a look at the Beeb now.

[rubber_jonnie]

OK, so progress is progress I suppose.

I think the problem with the A5000 is memory. I've removed everything and flattened the config down to just a floppy disk, so nothing else at all connected, and the 2MB RAM board removed. I then boot to desktop.

If I leave it long enough it just crashes, so no ifs, no buts, it gets all sorts of exception errors and on screen corruption. So I think I'll pull the board and look for signs of further corrosion around the RAM, or other damage (I thought I'd got it, but you never know) and see where that takes me. I'll likely re-cap it whilst it's apart.

Now over on to the BBC B. I found this when looking more closely at the FDD socket:

IMG20241130164203.jpg

Can you spot the bad thing? Wow I thought, gotcha now but I get the same error messages as before with the Gotek even after fixing that!

I think I need to pull the mainboard and double check for bad joints on the FDD socket, and I'll do some more digging around using a Gotek with a BBC in case I've done anything dumb.

I have already gone through the install instructions for the 177X floppy interface and that all looks fine, as does the 8271 installation.

Also, I get the same error with the machine that has the 8271 FDD controller installed. I know it isn't the cable as that is brand new and buzzes out perfectly, and it isn't power because I'm using a known good external PSU.

Bit of a head scratcher. Also I think my head is going to explode!

:dizzy:

[HigashiJun]

Better to cool down and do one thing after another.

But I perfectly understand you...