Sinclair ZX80 / ZX81 / Z88 Forums

Any corrosion shown on your ZX81 motherboard? Try a little emery cloth sandpaper. Try giving these ICs some "pullings out" and "pushings in" their IC sockets to break oxidization and set up good contacts. Retest.

DesSony

For my recent post above here, I decided that I am generous and I scanned 4 pages of the certain article and turned it into a file. I checked the opening web-link again. :oops:.... However, here is a scanned page 86 of the certain SYNC magazine issue! :D :lol: Extensions to Basic _Page 86.pdf Cheers...

Gammaray and Mrtinb,

Good news, I happen to have a certain SYNC magazine issue with its pages INTACT!
Pages 86 - 89 I scanned these pages into a 600 dpi PDF file. Cheers,

DesSony

Jeroen1328,

Welcome to this forum.

Transistors sometimes break down. What does their labels show you?

Thank you very much in advance.

DesSony

Repetto74,

Yikes.... Brand new keyboard with its brand new strips scratched! However, I have to concur with RWAP 100%. He(RWAP) deserved an applaud from each of you! I am very happy to know that you checked the continuity from pin 3 and ULA pin 29 and it is OK.

DesSony

Repetto74,

Middle contact = 3rd pin of 5 pins connector. Yes.

DesSony (Bill)

These gentlemen are right because I exactly did thing. Can you get your multimeter out and set it for a diode check or a continuity tester? Hold a probe on the 3rd "finger" of the 5 pins connector and hold another probe on an ULA's pin # 29. Inform us of the result here. Check the ULA's socket hole ...

DaveR,

Welcome to the world of the Sinclair ZX80, ZX81, Sinclair Timex 1000, S/T 1500 computers!

DesSony

Does your computer show its white "K" and its black square on the white screen? Can you touch an end of a wire on a middle pin of the 5 pins connector and another end of the wire on one pin of your own choice of the 8 pins connector and check the result on the screen? Maybe you have to evaporate som...

Repetto74,

Try cleaning a 5 pins strip connector with some very fine emery sandpaper. If not working then buy a new set of connectors.

DesSony