Trying to fix my ZxSpectrum+
Re: Trying to fix my ZxSpectrum+
Ram arrived! Check pictures. There is still issue.
I uploaded also a video, I pressed reset button after a bit.
http://imgur.com/a/0UGyyEQ
As a test, i checked all voltage on upper Ram module on pin 8 and i have all 4.98V.
I uploaded also a video, I pressed reset button after a bit.
http://imgur.com/a/0UGyyEQ
As a test, i checked all voltage on upper Ram module on pin 8 and i have all 4.98V.
Re: Trying to fix my ZxSpectrum+
I double checked the wires I soldered for Lower ram traces and I discovered a wire not connected!
I download OTLA software and try to load some .tap:
I download OTLA software and try to load some .tap:
Last edited by Hyuma on Wed Aug 07, 2019 7:35 pm, edited 1 time in total.
- DouglasReynholm
- Manic Miner
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Re: Trying to fix my ZxSpectrum+
Hurrah! Really happy to see this mate, I applaud your perseverance.
Also big thanks to everyone who helped Hyuma, I knew I could rely on you when they first enquired about their problems on another (inferior) website, and I suggested a better place to ask!
*sheds small tear and salutes
Re: Trying to fix my ZxSpectrum+
I've noticed that with OTLA loading games some are working, some others not, dunno why... and not all keys are responding when i press... maybe the keyboard need some clearing or some other to check?
Re: Trying to fix my ZxSpectrum+
Thank you so much, friend!DouglasReynholm wrote: ↑Wed Aug 07, 2019 7:35 pmHurrah! Really happy to see this mate, I applaud your perseverance.
Also big thanks to everyone who helped Hyuma, I knew I could rely on you when they first enquired about their problems on another (inferior) website, and I suggested a better place to ask!
*sheds small tear and salutes
- Ast A. Moore
- Rick Dangerous
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Re: Trying to fix my ZxSpectrum+
OTLA can only modify the standard loader. It can’t magically scan and figure out every non-standard loading scheme. Also, keep in mind, that due to the way the OTLA loader reads from the port, you can’t press any keys while a game is loading; it’ll introduce errors.
You can manually short each of the pins of KB2 sequentially with each of the pins of KB1. If some are not responding, than the problem is either with the ULA, diodes D1–D8, or the PCB traces. If they check out, then the problem is with the keyboard membrane, which, in all likelihood, will have to be replaced.
Every man should plant a tree, build a house, and write a ZX Spectrum game.
Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
Re: Trying to fix my ZxSpectrum+
Usually the ribbon part develops microscopic fractures on the bend as the plastic degrades which eventually breaks continuity in those metallic paint tracks. Since you've got it open you should replace the membrane. The new ones are made of a better material.
I also applaud your persistence, it's been an interesting thread to check back on. It must be satisfying to have resurrected this machine.
I also applaud your persistence, it's been an interesting thread to check back on. It must be satisfying to have resurrected this machine.
Re: Trying to fix my ZxSpectrum+
I know nothing about electronics but like others enjoy following the progress of threads like these..
If it's at the point where it just needs a new membrane it's a great success story (even I can change one of those!).
It shows all your work and persistence have finally paid off.
If it's at the point where it just needs a new membrane it's a great success story (even I can change one of those!).
It shows all your work and persistence have finally paid off.
My Speccy site: thirdharmoniser.com
- Muttley Black
- Microbot
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Re: Trying to fix my ZxSpectrum+
Congratulations! Don’t bother keep or fix that membrane.
Change it with a new quality one. You can buy it from Retroleum.
Or if you can fix it, do that and keep it for testing
Change it with a new quality one. You can buy it from Retroleum.
Or if you can fix it, do that and keep it for testing
Re: Trying to fix my ZxSpectrum+
I want show you something curious...
In this picture, you can see on my mat a white/beige shadow line pointed by my red probe. That is the result after cleaning the black dirt from the membrane. Seems like that IPA removed with the dirt also the conductive material of the tracks on the membrane . So after the cleaning I've 0 keys working and I will buy one new the next weeks. I don't know if that is the result of corrosion or not, but on my mat now I have some some part of the membrane's tracks .
In this picture, you can see on my mat a white/beige shadow line pointed by my red probe. That is the result after cleaning the black dirt from the membrane. Seems like that IPA removed with the dirt also the conductive material of the tracks on the membrane . So after the cleaning I've 0 keys working and I will buy one new the next weeks. I don't know if that is the result of corrosion or not, but on my mat now I have some some part of the membrane's tracks .
- 1024MAK
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Re: Trying to fix my ZxSpectrum+
Yeah, I strongly advise against using IPA or any other solvent cleaner on any keyboard membrane.
For cleaning the plastic part of the membrane, only use a cloth moistened with soapy water, then another with clean water, then dry.
For the conductive copper "strips", you have to be rather careful as they are only a thin film. Apart from the areas where they connect to the PCB connector, and the area where two membrane layers connect together (plus keyboard only), don't worry about them going black in colour. The black colour may well be tarnish due to the copper actually being an alloy rather than pure copper (which goes green rather than black when exposed to moisture and oxygen).
Having said all that, it was probably unrepairable anyway.
Mark
For cleaning the plastic part of the membrane, only use a cloth moistened with soapy water, then another with clean water, then dry.
For the conductive copper "strips", you have to be rather careful as they are only a thin film. Apart from the areas where they connect to the PCB connector, and the area where two membrane layers connect together (plus keyboard only), don't worry about them going black in colour. The black colour may well be tarnish due to the copper actually being an alloy rather than pure copper (which goes green rather than black when exposed to moisture and oxygen).
Having said all that, it was probably unrepairable anyway.
Mark
Standby alert
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
- Muttley Black
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Re: Trying to fix my ZxSpectrum+
Now that you job is done and you have a working spectrum, don’t forget to give a good cleaning to your motherboard with isopropyl alcohol and toothbrush.
It is very important. I saw lot of flux on your soldering work.
It is very important. I saw lot of flux on your soldering work.
Re: Trying to fix my ZxSpectrum+
Hey long time i didn't post nothing, this week i'll go to an important flea market for electronic in Modena. I hope to find some spare parts for my ZX (rubber keyboard, capacitors, etc..). Lately i was busy to repair some C64.