Commodore SX64 "finger assisted" repair (an easy one).

[@Miidolf]

Always an pleasure to watch you fixing up C= things. Thank you :)

[@marcopantanetti4053]

Great video Frank, thanks to share, i love the SX64 and It's always a pleasure to see it repaired

[@iz8dwf]

Grazie Marco!

[@jandjrandr]

First time seeing the SX64 main board. Would like a better view of it to compare with C64. When you gave the description of a black screen and chips from 1983 my first thought waa PLA failed. It is such a common failure for those year PLAs. My second thought was CPU, but you diagnosed it well. Great work!

[@iz8dwf]

I'll try to make a better "SX64" internal view video one of these days if there's enough interest. PLAs do fail indeed, but only the MOS "compatible" ICs, the other SX-64 for example has the F-93459DC FPLA and I don't expect it to fail anytime. 6510 are reliable enough, I think I've seen two failed ones in all repairs from 1986 up until today.

[@deborahberi3249]

Still a Great Video...I was waiting for you to run Lunatico, lol. -Mark.

[@iz8dwf]

Hi Mark! Sadly most of the new demos sound bad on the old 6581 SID. I do have a very good demo that was made for the 6581 but I didn't think about running it.

[@mondocommodore]

Ottimo video!! I video di riparazione (semplice o complessa) sono sempre ben graditi, soprattutto se ben documentati!! Per quanto riguarda la sostituzione dei pla, hai dei componenti programmabili ancora in circolazione e abbordabili? Ho le attrezzature per programmarli, però fatico a reperire informazioni in merito su quali componenti usare senza dover usare adattatori

[@iz8dwf]

L'unico componente che non necessita di adattatore e' appunto la PLA originale: 82S100, PLS100, F93459 e 556RT2 (clone sovietico della 82S100). - The only replacement that doesn't need any adapter is one of the original field-programmable PLA ICs: 82S100, PLS100, F93459 and the soviet clone of the 82S100, the 556RT2

[@mondocommodore]

@@iz8dwf tutti ormai introvabili (vergini)

[@petesapwell]

I had no idea the PLA was a 82S100 in disguise :)

[@iz8dwf]

Good to help Pete! The MOS part is a mask-programmed NMOS functionally equivalent to the 82S100, of course it isn't as reliable as the old ones. If you ever need an 82S100 replacement, I have a few spares left :)

[@petesapwell]

@@iz8dwf Thanks Frank :)

[@PleaseExplainMe]

Which diagnostics are you using?

[@jandjrandr]

Honestly I'd like to know as well

[@iz8dwf]

That was a cartdrige called "C64 BURN-IN TEST" that we copied in the '80s, no idea if it's available already for download (but I might copy it from my floppy disk. I also have no idea if the original cart had some diagnostic harness, we always used the program to check for non obvious faults after a repair (or confirm it was ok to return to a customer).