Sinclair ZX80 / ZX81 / Z88 Forums

Plus cases come up quite often on ebay, pots more room inside if you don’t particularly want the original style. Otherwise you might need to pick up an original ULA. Thanks for the reply! That is a good idea, and also i am considering if i will attempt to do a 3d model of the case then i could prin...

Hi there Sinclair people! :) So not all posts can be just about problems and ignorance in display :) I am happy to report hat so far i have been able to play with my zx without issues (apart my all time favorite R-Type included in dandanator rom making strange artifacts)! All tests run fine and OK, ...

Ok got my new ULA today but will not touch anything until Mark has a chance to give me a help to check what is needed and if i can plug it in.

1024MAK wrote: ↑Thu Jan 25, 2024 6:22 pm Sorry, been busy with my real world job. I'll reply later once I've caught up.

Mark

Always first!
I am already very thankful someone - you - is helping me!

Have a great time

So this morning spent +3h checking all i can in detail, retouching the solder on mostly everything i touched before or may have. Now it's kind of back to the normal not working as expected after recap i guess. So i have left the wire to disable upper ram (pin 5 of IC23 and + of C34), put lower ram b...

You absolutely spot on. Should i put the original back? Don't know what to do, never had issues like this where replacing a "simple" components would end up in strange results. Gonna re-review all solder, all pcb connections for shorts or drops of solder or whatever.... what i can not really underst...

So..... Was without the upper ram disable. Well.... so i got the package from Phil with new TR4 and TR5 replacements. TR4 was already done so i went to remove the TR5 and put the new one. And it boots to the dandanator card with nice picture and all seemed fine. I reset power to press it to boot to ...

Hello there! So i replaced TR4 and now yes there is color in the image and first time it booted into normal sinclair screen but after some seconds started beeping and went to black center with some red stripes in the top of the square. I had the lower ram board plugged in. Now i removed the ram boar...

Ok... After a shaming amount of time i managed to remove the TR4 as you told to do, remove the remain parts of legs, and solder something to it to test on the multimeter (something i never done before). tr4.jpg Yes the TR4 (ZTX650) give 000 on the test. I had 2 BC549C that came with the recap kit an...

Hi there Mark! Well here we dealing with 20cm of snow :) So yeah, i am going to pick a damaged board and work on my soldering skills. Is really important and normally it does not go so bad.... but with the zx i really had issues to do it right. Do you work on electronics repairs? If so do you repair...