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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment. |
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12th Mar 2020, 9:07 pm | #21 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,484
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Re: ZX Spectrum Tuning Issue
On that black remote, the 'AV' button south-west of the main circular group of buttons would be the one which selects the video input, but only if the remote is an exact enough replacement for that to work.
Edit: Caught me again, I'm going to have to give you more time. OK, so do you have anything else, a DVD player for example, which can output a composite video signal which you can feed into the AV input to test that? |
12th Mar 2020, 9:46 pm | #22 |
Hexode
Join Date: May 2013
Location: Middlesbrough, North Yorkshire, UK.
Posts: 442
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Re: ZX Spectrum Tuning Issue
It appears to be working! I wonder why
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12th Mar 2020, 9:50 pm | #23 |
Hexode
Join Date: May 2013
Location: Middlesbrough, North Yorkshire, UK.
Posts: 442
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Re: ZX Spectrum Tuning Issue
Yay!
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12th Mar 2020, 9:51 pm | #24 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,484
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Re: ZX Spectrum Tuning Issue
Nice clean looking picture too. Maybe just tidying up that mod did the trick.
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12th Mar 2020, 10:18 pm | #25 |
Hexode
Join Date: May 2013
Location: Middlesbrough, North Yorkshire, UK.
Posts: 442
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Re: ZX Spectrum Tuning Issue
However!!!! Now it won’t load software! I’ve connected the ‘ear’ output from the tape recorder to the ‘mic’ socket on the spectrum - it doesn’t load and I don’t hear the bleeps which I remember I used to hear! I’ve tested the cassette player with headphones and there is output alright. I’ve tried two sets of leads so either both leads are damaged or it’s the Spectrum ! I could try a beep command?
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12th Mar 2020, 10:19 pm | #26 |
Hexode
Join Date: May 2013
Location: Middlesbrough, North Yorkshire, UK.
Posts: 442
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Re: ZX Spectrum Tuning Issue
Just when you thought you had it sussed!
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12th Mar 2020, 10:21 pm | #27 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,484
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Re: ZX Spectrum Tuning Issue
Audio out / Earphone out on the recorder should go to EAR, not MIC, when trying to load programs.
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12th Mar 2020, 11:27 pm | #28 |
Hexode
Join Date: May 2013
Location: Middlesbrough, North Yorkshire, UK.
Posts: 442
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Re: ZX Spectrum Tuning Issue
Sorry-yes-that’s what I meant! Very late and I have a little brain!!
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12th Mar 2020, 11:27 pm | #29 |
Hexode
Join Date: May 2013
Location: Middlesbrough, North Yorkshire, UK.
Posts: 442
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Re: ZX Spectrum Tuning Issue
Ear out from cassette to Ear on Spectrum
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12th Mar 2020, 11:29 pm | #30 |
Hexode
Join Date: May 2013
Location: Middlesbrough, North Yorkshire, UK.
Posts: 442
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Re: ZX Spectrum Tuning Issue
Haven’t tried saving any yet - will try tomorrow
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12th Mar 2020, 11:39 pm | #31 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,484
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Re: ZX Spectrum Tuning Issue
Are you by any chance expecting to hear the sound of the loading program coming out through the TV? That didn't happen on the original Spectrum, sound only came out through the little onboard speaker as far as I know. Only in later Spectrums was the sound superimposed onto the video signal so that the sound came out through the TV.
If you actually want to hear game sound coming out of the TV, use an appropriate (3.5mm mono jack plug to phono plug) lead to connect the MIC or EAR socket (whichever works best - EAR will be loudest) on the Spectrum to the red or white socket on the AV-input on the TV. |
12th Mar 2020, 11:46 pm | #32 |
Hexode
Join Date: May 2013
Location: Middlesbrough, North Yorkshire, UK.
Posts: 442
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Re: ZX Spectrum Tuning Issue
No. I’m expecting the sound to come out of the Spectrum. But it isn’t ☹️
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12th Mar 2020, 11:51 pm | #33 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,484
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Re: ZX Spectrum Tuning Issue
In that case try one of the sound example programs from the manual or some other source as you yourself suggested to see if the onboard speaker is still working. Although, didn't you say you were hearing key clicks during your 'trying to get a picture' phase earlier?
I seem to remember that the speakers do fail, one or two of the retro spares sellers used to stock them. |
13th Mar 2020, 7:49 am | #34 |
Hexode
Join Date: May 2013
Location: Middlesbrough, North Yorkshire, UK.
Posts: 442
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Re: ZX Spectrum Tuning Issue
Normally, when you load a program, the screen around the central display area flickers rapidly with lines to indicate that the program is loading, you also get to hear the program bleeps as it does so. Neither is happening. Last time I used the Spectrum, which was about a year ago, it did those things, notes nothing. It just won’t load anything. When you press a keyboard let you can hear the little ‘click’ so I think the speaker is fine. Later today when I get home, I shall try to save a program. I’m not sure why this has stopped all of a sudden.
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13th Mar 2020, 10:47 am | #35 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,484
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Re: ZX Spectrum Tuning Issue
Saving a program and then listening to see what has been saved will be a useful test as the tape-out and tape-in signals actually come out of / go into the same ULA pin.
Another check, plug your tape in/out lead of choice into the EAR socket, then measure from the tip of the plug at the unconnected end of the lead to the socket contact furthest away from the edge of the Spectrum PCB -should be zero resistance - and measure from the 'ring' on the plug on the unconnected end of the lead to the socket contact closest to the edge of the PCB - should also be zero resistance. Doing it this way is useful for two reasons - one, it checks the socket as well as the lead, and two, it holds one of the plugs on the lead still / steady so you only have to chase one of them around the bench with your meter. (On the ZX machines the 3.5mm EAR and MIC sockets have conveniently open construction so you can easily get to the socket contacts as they are exposed on the top of the socket). |
13th Mar 2020, 9:52 pm | #36 |
Hexode
Join Date: May 2013
Location: Middlesbrough, North Yorkshire, UK.
Posts: 442
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Re: ZX Spectrum Tuning Issue
Okay folks-I tried saving a short program. The Spectrum put out the usual flickering border to indicate that it is saving something but when I played it back all I got was a lot of loud background hiss and humming. Exactly like it was when trying to save programs from the ZX81. I suspect that it’s the tape recorder-though it plays back from the speaker fine. What do you think? I tried the beep command and that works fine. It could the the cables of course so I shall try the suggestions above.
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13th Mar 2020, 10:18 pm | #37 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,484
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Re: ZX Spectrum Tuning Issue
Do that first, I think. "Always try the simple stuff first". Let us know what you get.
Is the cable the original two grey plugs / two black plugs cable which came with the Spectrum? |
13th Mar 2020, 10:38 pm | #38 | |
Hexode
Join Date: May 2013
Location: Middlesbrough, North Yorkshire, UK.
Posts: 442
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Re: ZX Spectrum Tuning Issue
Quote:
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13th Mar 2020, 10:39 pm | #39 |
Hexode
Join Date: May 2013
Location: Middlesbrough, North Yorkshire, UK.
Posts: 442
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Re: ZX Spectrum Tuning Issue
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13th Mar 2020, 11:36 pm | #40 | |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,484
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Re: ZX Spectrum Tuning Issue
Quote:
-Tip of the plug which is not plugged in, to socket contact furthest away from the edge of the spectrum PCB. (Should be zero ohms) -'Ring' of the plug which is not plugged in, to socket contact nearest the edge of the Spectrum PCB (should also be zero ohms). As mentioned a while ago, if you are looking for an expected resistance value (zero ohms in this case) use the meter range which has the next highest resistance value. On your meter I think that would be the 200 Ohm range. Can you confirm that the plugs on the ends of the leads you are using have two sections, not three (are mono, not stereo)? Also are these pre-formed leads with moulded plugs, or can the plug covers be unscrewed to expose the connections inside the plug? |
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