So the Keyboard membrane came in finally. Works just fine. I cleaned up the case really well and washed it thoroughly. I removed the deteriorated foam feet (one was missing anyway) and replaced with some small rubber sticker feet I had. I cleaned off the old dried adhesive and washed the membrane. Put it all back together and it loooks better and the KB works.
So next step try and diagnose bad ram. I am trying to load the test diags from a TAP file from this site:
https://github.com/brendanalford/zx-diagnostics
At first I tried my cell phone with a mono audio cable. Nothing. Then my old Ipad.. Nothing. I cant even hear the audio coming out the ZX spectrum speaker which I thought was supposed to happen.
It occured to me the cassette jacks might be dirty so I used some bristle brushes dipped in deoxit and cleaned out the audio jacks. I dont remember what triggered it but the thought occured to me the audio may not be loud enough or the ZX was not sensitive enough to "hear" it. I decided to get some amplified speakers, connected both my phone or Ipad into the speakers and use the mono audio cable from the zx spectrum to the headphone jack on the speaker. That way I can modulate the volume and the tone knob.
This finnally gave results. I could see the red and blue bars for the first time as well as hear the sounds come out the spectrum when the audio knob on the speaker was sufficiently high enough.
This seems strange to me as the volume on the phone and ipad were MAX and it still didnt trigger anything, why is that? Could something on the ZX spectrum that picks up the audio signal be faulty?
Anyway with lots and lots and lots of playing around (hours.. maybe 3) I was able to get the actual file name to come up on the zx spectrum screen. If the tone or volume goes up or down a hair, some letters in the tile might not be right.
Either way I never got it to load anything. I would get BASIC errors, or Tape errors, or RAM errors. I stopped after sufficient frustration. In the end I used my laptop, with the stereo speakers and a program called OTLA
https://code.google.com/archive/p/otla/downloads got the idea watching a video of Mark fixes stuff. Seemed to give the best results so far anyway.
On another note. The small 4:3 LCD TV I thought was working only seems to work in monochrome. Any adjustment on the ZX which was color shows a complete mess. I decided to hook it up to our Primary Television downstairs and it works fine on with proper color (although I will need to tweak it when its all said and done for best picture.
So I am at a loss. I cannot load a single program even the tiny 8KB diagnostic program. Should I build the diagnostic ROM at this point? Any Ideas?
Really frustrated.