Sinclair ZX80 / ZX81 / Z88 Forums

Thank-you kind Sir!
As always your advice is hugely appreciated. Will get both parts and commence surgery within the next couple of days. Will post here with an update on how the patient is doing.

So here's where I'm at with this project. Finally everything I need to get started has arrived. (well everything that had to come from overseas). Also as a bonus a second boxed ZX81 that I bought from someone in the UK on ebay arrived and its in perfect working condition. Honestly the RF image was s...

Thanks for that Lardo Boffin. Looks like a useful page for the components although I will probably source the regulator and other components from here in New Zealand as much as possible. They seem to be very cheap which is a bonus. I havent posted anything here for a couple of weeks because im waint...

Wow that's amazing thanks so much Mark. Your rundown is such a huge help. From the information you've provided ive figured out that I need to do the following to bring her back to life. 1. Buy a replacement membrane keyboard. (although I might see if i can temporailty use a craft knife to square off...

Right thank-you. Wow I didn't look very hard did I. Okay here are two pics of the USA zx81 I will be doing my best bringing back to life. Most likely will be installing a composite mod and will probably have to replace the 7805 regulator (unless im very lucky). Thanks for your advice on components a...

Thanks very much 1024MAK. I opened it up this morning and took really detailed Hi-res pics of the motherboard. Really interesting stuff. I found the 7805 regulator right away. The motherboard seems very clean with no burn or damage to anything but i know that not necessarily an indicator. Naturally ...

Thanks very much to both 1024MAK & mrtinb. Yes i'm assuming that in my stupidity I fried the ZX81 with the wrong polarity PSU. So I'm considering it a repair project now. I don't know for sure that the polarity was wrong but it got so hot so fast that I knew something was wrong right away. On the pl...

I have a zx81 project that I have a few questions about. I bought an old zx81 (paid way too much) and want to bring it back to life but discovered a few quirks and things that I need advice on. 1. Randomly even though I live in New Zealand for some reason this one turns out to be an American one. I ...