I lost my Timex Computer 2068 when I moved to my new house about a decade ago, although I still had the transformer, tape recorder and tapes. So this week I decided to buy a Timex Computer 2048 for nostalgia.
The problem with the TC 2048 is that it doesn't load games. This symptom was confirmed by the seller before the purchase. I turn it on, type LOAD "", press play on the recorder and no blue/red borders appear, it just stays white. It's not a color problem because the TC2048 is connected to the TV with a composite cable (it has a "monitor" connection) and I can see them with the COLOR 2 and COLOR 5 commands. I can also hear the tape recorder sound exiting from the internal speaker. Well I could, until I opened the TC2048 and accidentally disconnected one of the wires connected to the internal speaker.
So, the sound seems to be passing through the jack connection, but not getting to where it should be. Is this a problem with a known solution?
TC 2048 sound input problem
- 1024MAK
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- Joined: Mon Sep 26, 2011 10:56 am
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Re: TC 2048 sound input problem
It's the custom logic chip that "receives" the input from the Ear socket.
When "LOADing" don't have the "Mic" lead connected. As with some tape decks this can cause an audio feedback path .
Turn the volume on the tape deck to somewhere between 3/4 and maximum. Remember, the audio signal from the tape deck has to be detected by a 5V logic chip that may consider voltages below 2V to be logic zero (this is an approximation, as we don't actually know the specs of the custom logic chip).
Mark
When "LOADing" don't have the "Mic" lead connected. As with some tape decks this can cause an audio feedback path .
Turn the volume on the tape deck to somewhere between 3/4 and maximum. Remember, the audio signal from the tape deck has to be detected by a 5V logic chip that may consider voltages below 2V to be logic zero (this is an approximation, as we don't actually know the specs of the custom logic chip).
Mark
ZX81 Variations
ZX81 Chip Pin-outs
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ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Autumn is here. Bye bye summer 2024...
Re: TC 2048 sound input problem
its usually when saving you dont want to have both leads connected? never known of a cassette recorder to take input on its mic socket when playing, but some certainly feed the mic input back out the ear socket when recording..??
- 1024MAK
- Posts: 5332
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: TC 2048 sound input problem
Yep, that's the main reason, but if you do have loading problems, it's something that is easy to do just in case.
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Autumn is here. Bye bye summer 2024...
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Autumn is here. Bye bye summer 2024...
Re: TC 2048 sound input problem
I don't have the original "dual" cable, I'm using a custom cable I made from spare parts so I'm only connecting one jack. Another problem is that I'm a complete newbie when it comes to electronics: I have a soldering iron, a multimeter, and that's it.1024MAK wrote: ↑Thu Jul 13, 2017 3:06 am It's the custom logic chip that "receives" the input from the Ear socket.
When "LOADing" don't have the "Mic" lead connected. As with some tape decks this can cause an audio feedback path .
Turn the volume on the tape deck to somewhere between 3/4 and maximum. Remember, the audio signal from the tape deck has to be detected by a 5V logic chip that may consider voltages below 2V to be logic zero (this is an approximation, as we don't actually know the specs of the custom logic chip).
Mark
However I did notice that a capacitor has been replaced, the one on the far right just below the power switch, the new one says 100uf 40v. I don't have a picture from my motherboard, but it's very similar to the one below, except mine doesn't have the 2nd and 4th chip from that group of 4 chips in the bottom right.