H4 FIXES & KNOWN ISSUES

[exxos]

Thought I would document "issues" as we go along as would help keep track of them all.

BATTERY HOLDER PAD ISSUE

https://www.exxosforum.co.uk/forum/viewt ... 310#p28481

There are no pads for the battery holder, just vias. Just be careful not to "short" the track as you solder it.

IMG_4715.JPG

FIX done to REV F

f1.JPG

MFP OSC ISSUE

https://www.exxosforum.co.uk/forum/viewt ... =10#p28950

The osc may need some small bodge wires (yay bodge wires!) to lay it flat as its right under the floppy drive.

IMG_4545.jpeg

FIX done to REV F

2.JPG

[exxos]

DTACK FIX

There was some last minute changes to the flashy clock integration where DTACK was split via jumpers on the previous design, but it was supposed to be put back "hard-wired", but wasn't :roll: So we need a small bodge wire on the bottom of the PCB (top view shown)

Capture.PNG

EDIT: Picture of patch in place on the bottom of the board

IMG_4561.jpeg

DMA RESISTOR LOCATION ISSUE

Icky found this issue.. https://www.exxosforum.co.uk/forum/viewt ... 998#p28984

I swear I fixed that though :roll: (EDIT: though might have been the MFP resistor I moved and didn't notice the DMA one :roll: )

Anyway, More of a "note to self" to fix it on the next board.

dmares.jpeg

[exxos]

LOCATION LUG HOLE MISSING

Icky found this small issue. I didn't do any of the location holes (just wasn't enough time in the end) but these are easy to remove with cutters, file, sledge hammer etc.

I am not totally sure if all cases have the location lugs and holes in the same places either (in fact I don't think they do) . I think the screw hole may be in slightly different locations as well, the original STFM boards had a oval hole for some reason. So it may not align in all cases ( pun intended ;) )

hole2.jpeg

FLOPPY CONNECTOR MISALIGNMENT

Not sure if there are different connectors, or just never got tweaked...

floppy.jpeg

[Icky]

FLOPPY CONNECTOR MISALIGNMENT

Not sure if there are different connectors, or just never got tweaked...

You can get these to fit by gently squeezing the two pins together with some pliers. Once they fit in the hole the connector will fit flush against the board.

[exxos]

BGACK MISSING PULL UP

So yeah, I did it again :roll: :lol:

There is no BGACK pull up resistor. It needs one adding, anything around 2.2K should be fine. This should be 1K as outlined in THIS POST.

oopsies.JPG

[Icky]

How the patch looks in place

IMG_4575.jpeg

[PaulJ]

How the patch looks in place

Icky, did you sneeze on your board? :mrgreen: :mrgreen: :mrgreen:

[Icky]

@PaulJ - That is the solder I have. It's a PITA. It spits flux out in little balls and that is the speckled effect you see.

[exxos]

@PaulJ - That is the solder I have. It's a PITA. It spits flux out in little balls and that is the speckled effect you see.

I'm using this one...

https://www.rapidonline.com/warton-meta ... 0g-85-6242

Don't like the note about lead-free though... Maybe we should start stocking up on solder now.. :roll:

[PaulJ]

@PaulJ - That is the solder I have. It's a PITA. It spits flux out in little balls and that is the speckled effect you see.

Thats pretty disgusting, there's nothing I like about lead free solder! I'll just stick with my ole legacy lead solder. I use some 0.02 stuff from China which I like much better than the 0.032 solder. With the tip TF recommended for SMT work it is the perfect size for me.

IMG_2306.jpg