How ELSE does the PET-style keyboard differ?

[TheAnachronaut]

I have a VIC with a PET keyboard and one with what I see people calling a “eurostyle” keyboard, both with 2-prong PSUs. I swapped “tops” after the older VIC lost video. With my PET-VIC hybrid machine, cartridges and tapes seem to play perfectly; all seemed well, for months. I installed a test cart and harness. The test quits with a keyboard error. Why? More recently, I loaded “VIC Typewriter” and the function keys operate differently than described in the manual; F5 will not save. Also the HOME key refuses to work.
Has anyone noted that the PET keyboard misbehaves when installed on anything but the earliest VICs? Would it agree with a VIC-1001, an early Brit-VIC?
Yours, Mark

[TheAnachronaut]

Sorry, “Eurostile.”

[srowe]

The VIC-20 (and C64) keyboards have no active components. They're just matrix of switches which are scanned row and column to work out which keys are down. The pinouts of the cable are identical between all versions.

If the test cart indicates a failure it could either be the keyboard itself of the VIA it is connected to. If your VIAs are socketed try switching them around and retesting. I did have a rather subtle issue with the keyboard on my C64, a track had corroded so that certain keys on one column didn't work (but others did). This was fixed by stripping down the keyboard and soldering a bridge across the damage.

[eslapion]

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[TheAnachronaut]

Back in 2006, I performed a treatment on it to make the keys sensitive again. I used the expensive kind of product, not the cheap kind which fails

I am mystified. Did you apply gold leaf to the circuitry? Did you lubricate the key switches with truffle oil?

[eslapion]

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[TheAnachronaut]

The product may not be gold, but the tip IS. Does treatment repair a particular keyboard issue, or should it be given before problems arise?