Cleaning Pads - How did I do?

[smrieck511]

I'm in the process of cleaning the pads. I'm going to tin them and add the caps tomorrow.

I *think* I did ok? would love any expert advice.

The trace on the positive side of C4 concerns me a little. Possibly looks broken, but the last photo shows the original cap and it appears to be in the same condition. Might be fine? It did boot with sound before, but the sound was low which I'm assuming/hoping was degrading caps.

 

[imactheknife]

Check continuity from actual pad to where the trace goes to.. then you will know 100 %. That would be a really easy fix to if its broken right there too

 

[smrieck511]

Ah good point. Hard to tell where the trace goes though. I assume to one of the pins on the corresponding Sony sound chip. But which one?

 

[chiptripper]

Nice work!

I wouldn't worry about C4, probably just the solder mask. You can very carefully scrape it back to check that the copper underneath is ok. I don't remember where this trace goes but you could just buzz all the legs I guess.

Might check continuity from positive C1 to wherever it leads. The solder is dull and darkened, sometimes cap goo + time turns solder into a useless, resistive lump.

 

[imactheknife]

There is a diagram about for the se/30 sound circuit

 

[smrieck511]

This is helpful! Hopefully wont need it.

 

[imactheknife]

This is helpful! Hopefully wont need it.

Doesn’t take long and is a good thing to check. But yeah, if everything works then no real need

 

[smrieck511]

Continuity is ok on + C4.

As far as I can see, looking at the back of the board, + C1 leads to nothing? Just an isolated point?

Now my thought is the pad size on the tantalum caps. These are wide and could contact traces? The traces on this board look ok but is this ever an issue? Would extra solder mask on the traces in question be useful?

 

[chiptripper]

+C1 connects to the +5v plane, so you can test for continuity anywhere that's also connected. +C12 or +C13, say.

Usually no issue with tantalums making contact where they aren't supposed to, but it's a good thing to be aware of. Occasionally I place the cap slightly to one side or at an angle if it looks like there's any risk.

 

[smrieck511]

+C1 connects to the +5v plane, so you can test for continuity anywhere that's also connected. +C12 or +C13, say.

Usually no issue with tantalums making contact where they aren't supposed to, but it's a good thing to be aware of. Occasionally I place the cap slightly to one side or at an angle if it looks like there's any risk.

Thanks for the help. I checked Continuity from
+ C1 to + C12 and everything looks good.

 

[smrieck511]

Just finished soldering in the capacitors. Tantalum polymers… And it boots with sound!

Thank you so much for all the help! Literally could not have done it without 68KMLA

 

[chiptripper]

Congrats!

 

[smrieck511]

Congrats!

Thanks! Man, I was terrified when I flipped that switch this morning lol.

 

[3lectr1cPPC]

Thanks! Man, I was terrified when I flipped that switch this morning lol.

I’ve been there. Good work!

 

[Cam]

Just finished soldering in the capacitors. Tantalum polymers… And it boots with sound!

Thank you so much for all the help! Literally could not have done it without 68KMLA

Congratulations! A little terrifying the first time, isn't it?

 

[smrieck511]

Congratulations! A little terrifying the first time, isn't it?

Thanks! and yes, I think you have to go into this hobby willing to lose but today I got lucky. Now some minor stuff to contend with. This floppy drive is like the little engine that couldn't... he's all heart. That smiley face comes up and he churns...and eventually it ejects the disc. it did actually fully boot to the desktop one time, but then had a disk error. I've cleaned the heads and completely cleaned out and lubricated the drive using the guidelines in the Adrians digital basement video... oh well, figuring this stuff I was why it's fun most of the time...some of the time.

 

[smrieck511]

I’ve been there. Good work!

Thanks!

 

[smrieck511]

Interesting.. booting from the 6.0.8 startup disk, no problem.