SE/30 Floppy Troubles

[uniserver]

lol buddy… spagetti is your only hope. hey, if spaghetti fixes it. then do it.

genie_mac has 3 of my SE/30 boards, and trust me spaghetti is these boards only chance.

Rather have a little spaghetti then have a screwed up board…

trace rot is trace rot.. via rot is via rot… that cap goo gets in there man.

no way around it with the SE/30.

btw genie_mac - if you can get them to not be completely dead,

any Sound/SCSI/floppy/Gangster Stripe/Screen diarrhea/ADB/ i could take care of - At-least for the 2 No Rom ones, The Video + Mouse curser and nothing else one… Well that one is just as dead as far as I'm concerned eg. heat gun scsi chip fun :-D

- yeah man be lucky if this is your only issue with these specific boards.

 

[uniserver]

hey man… do you have any info updates on this. also to re-cap, what wires did you have to run to get full capability back? from where to were and what pins? -- thanks… i am working on compiling a SHOT GUN fixes set of info, me and genie_mac feel there are a large amount of pattern failures with the SE/30 + Cap goo - Trace/VIA rot. Pictures are great too!.

 

[genie_mac]

It's just weird. It's actually the WR● line coming from pin 4 of UH7 to pin 2 of the SWIM... the issue is that my multimeter gives close to 0 ohms... Yet it just doesn't want to work without a direct lead between the two pins, or the scope between any of the above pins and ground...

Hi Ike,

did you ever fix this or manage to explain why this is happening?

I have a very similar issue where the machine will only work when I ground a certain pin (PA0 on VIA1 in this case) and I cannot figure out why. Very strange!

 

[Ike]

Unfortunately not :C!

That is the problem; I don't understand how a very simple, single connection from chip A to chip B only using the upper and lower planes of the PCB with two vias straight trough can cause ANY issues! As far as my testing goes the pins are not shorted out by any gunk or solder bridges, but I don't have access to a hot air desoldering station so I can't properly look under the chips.

The continuity is very close to 0 ohms so that can't really be an issue. I'm really having trouble understanding what goes wrong.

What does that VIA pin do and where does it go? Tried finding where it goes in the schematics but couldn't find it.

 

[genie_mac]

Pity you didn't get it working!

That VIA pin goes to the edge connector. I tried to built a diagnostics harness, which requires grounding that pin. The diags didn't work, but when I attached the connector, the faulty board booted right up. That pin is pulled up to 5V normally, but pulling it low got the board working. Once I removed the ground connection, the board would freeze. Very strange!

 

[Ike]

Yeah that's bizarre. Did you measure if the pin, when not grounded, is actually pulled up to 5V?