Using 5 NAND Gates to prove that there is a hardware problem was very useful, but for a production run using a single chip to replace these is the next step.
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| Part No | Chip | Manufacture | Speed nS | Package | Price | |||
|---|---|---|---|---|---|---|---|---|
| Min | Typ | Max | ||||||
| 1741279 | SN74LVC1G139DCTR | Ti | <2.5 | SM8 | $ 0.69 | |||
| SN74LVC1G139DCUT | Ti / Farnell | <2.5 | VSSOP | £0.404 | ||||
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The one pixel blue line for the board size is difficult to see unless viewed full size.
Layout with SO 16 footprint overlaid
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This shows that the holes line up with pads that need to be soldered.
Layout over the original PCB
This shows the area of the original card the board will cover. C2 needs to be removed (if fitted).
The 7 layers
Here are the layers printed on A4 sheetsas a pdf file. The board is small, zooming in is generally helpful.
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