Broke sound on my Oric Atmos, tips?

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xahmol
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Broke sound on my Oric Atmos, tips?

Post by xahmol »

Couple of months ago I bought a DIN to RCA audio cable to get music and sound from the Oric tape port to my mixer for external capture.

This worked great, till recently, when my mixer was not picking up any sound anymore. Music on the Oric's internal speaker still was working though.

So I was fiddling somewhat with the RCA plugs on my mixer, stupidly enough with the Oric powered on (yes, I know, whould never do that, but did it anyway by being a little bit too careless). And suddenly the internal speaker went dead, no more sound from it also after power off power on.
Thankfully the rest of my Oric seems to be working fine, also I do have a spare Oric (but there was a reason I was using this one).

So questions:
- Is it correct that fiddling with such a DIN to RCA audio cable connected to the tape port when powered on, can give a zap to the internal speaker (or something driving the internal speaker), making it mute? If yes, did I then have a wrong cable after all, or do you really have to be so careful also with the normal tape lead with the Atmos powered on?
- If not the above, what else could cause first the sound going away over the tape port, and then also via the internal speaker?
- Any tips to repair? Did not try anything myself yet, did not even have a look in the case yet (no time now).

(by the way: was busy trying to make a capture with sound from my new RGB2HMDI for my Oric. Picture is terrific on HDMI. But getting no sound and therefore did not yet succeed in the capture).
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kenneth
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Re: Broke sound on my Oric Atmos, tips?

Post by kenneth »

The audio cable can do a shortcut, try the Oric computer with the audio cable disconnected from the DIN socket. The LM386 amplifier is connected directly to the DIN socket, an electrostatic shock done when removing the audio cable can destroy this chip.
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xahmol
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Re: Broke sound on my Oric Atmos, tips?

Post by xahmol »

kenneth wrote: Wed May 11, 2022 4:39 pm The audio cable can do a shortcut, try the Oric computer with the audio cable disconnected from the DIN socket. The LM386 amplifier is connected directly to the DIN socket, an electrostatic shock done when removing the audio cable can destroy this chip.
That was the first think I tried: remove the cable and power up again. Still no sound. So I am afraid then that I indeed destroyed that chip 😢
Is that solvable! And if yes, solvable by a soldering handicapped person like me?

(And now start sitting in a corner being shamed that I broke my ‘never ever do anything with cabling connected to a retro computer while powered on’ rule)
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Dbug
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Re: Broke sound on my Oric Atmos, tips?

Post by Dbug »

Since your keyboard is still working, it means that the YM sound chip is still working, which is good :)

Other will correct me if I'm wrong, but I guess all you need to do is probably to replace this chip here:
image_2022-05-11_195852203.png
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Re: Broke sound on my Oric Atmos, tips?

Post by Chema »

I burnt my LM by using the Atmos to amplify my Spectrum. Yeah weird.

A friend of mine replaced it and that was all. However, I had sound out of the din socket.
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Re: Broke sound on my Oric Atmos, tips?

Post by xahmol »

Chema wrote: Wed May 11, 2022 10:17 pm However, I had sound out of the din socket.
That would actually be my ideal scenario: sound from the DIN socket for external use, but no sound from that crappy and noisy internal speaker....

So as I understand you correctly, the DIN port should still give sound with that chip blewn out? Because than my original issue of not getting any sound from the DIN anymore might still be solvable without exchanging the chip, giving me nice sound from external speakers and not noisy and no volume controllable sound from the internal speaker ;-)

Will do some further exploring.
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xahmol
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Re: Broke sound on my Oric Atmos, tips?

Post by xahmol »

You are right Chema, have sound via the mixer now again from the DIN port.
Sou Oric is playing music fine from the tape DIN port, just not from the internal speaker anymore. So maybe this unfortunate accident is even not that unhappy after all. Finally by accident found a way to shut the internal speaker up ;-)

Just woild have preferred a solution that is not that final.

And just to be sure: all that broken chip does is amplify sound for the intenal speaker? Really nothing else that I might miss now?

(and now still need to find out why my mixer can output the Oric signal over headphones, but not over USB to my PC, while my mixer can do so fro my C128 connected to the same mixer. This actually started my whole fiddling with cables)
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iss
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Re: Broke sound on my Oric Atmos, tips?

Post by iss »

xahmol wrote: Thu May 12, 2022 8:55 am And just to be sure: all that broken chip does is amplify sound for the internal speaker? Really nothing else that I might miss now?
That's correct! You have working AY-3-8912 (BIG luck!) and burnt LM386 which is only amplifier for the int. speaker.
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Re: Broke sound on my Oric Atmos, tips?

Post by xahmol »

By the way: this is the capture without sound that I made from my real Oric Atmos using a RGB2HMDI.... still not able to get the sound to my PC (which is really annoying, as my mixer can output it to headphones, but not USB, but that is not an Oric problem, but my skills with that mixer problem. It did work before though).



(and sorry DBug, still no scanlines. RGB2HDMI should be able to add those scanlines, but did not suceed yet in doing so)
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