Though a true answer lies after, I will start by answering your question with a question to put my answer into perspective:
Hello fellow dolphins who live under the waves of Dearth with me. I have come to
worldbuilding.stackexchange.dearthnet to ask a question about aliens.
As you know, our leading scientists believe that we might actually be
descended from non-intelligent dolphins from another planet, and the
religious folks too point to their bibles which state that
dolphin-kind came from the third planet out from a yellow dwarf star;
even though I find those verses hilarious, since they also state that
those dumb ancestors had something called "eyes" that allowed them to
sense EM radiation, and furthermore that there were creatures with
eyes but no echolocation, it does make me wonder since such creatures could not possibly get a good 3D view of the world around them and would likely be their own doom as they swam into objects because of their lack of depth-perception as we are accustomed...
Now, imagine a world where the dominant species is one without
sight echolocation, as defined as the ability to take
electromagnetic radiation sound waves and convert it into an
image. How could such a species overcome this huge disadvantage to
eventually become a space-faring civilization? Some thoughts I've
Now to get to the real answer, and let's think of it from the perspective of the Dearth dolphins.
As demonstrated above, humans themse-, I mean ourselves, have a similar problem already. There are numerous energies and forces which we cannot directly sense with our organs, and most of the EM energy itself is included in that. In the case of EM though, we have a leg up since we can at least sense part of it, seeing wavelengths from about 400-700nm.
Some of the things that humans cannot sense are things that other animals can sense. Take magnetism for example. There are many animals which have a sense that we unfortunately cannot tap into: magnetoreception. It does wonders in helping animals get around. I wonder if the birds looking at our airplanes think "How can those humans possibly have figured out how to fly a plane, and to reach such distant locations accurately nonetheless, when they cannot sense the earth's magnetic field like we can?" I also wonder if the birds can pick up at all on the magnetic fields of the sun or of other celestial bodies; probably not, despite the fact that you can tune in to hear Jupiter's static on a good radio.
How did we do it?
So, how have humans accomplished the feat of "seeing" energies and forces which we cannot directly see? We hypothesize the existence of something, figure out a way to test it, verify, create devices to detect it, then finally we convert the data into a different format which we can see.
Take an EEG graph for example, generated by an electroencephalograph. It is something that we cannot detect without the EEG, but we then turn it into a visual graph as on the linked page.
We do the same with devices that create graphs of electrical current and with seismography and many other things. We can view the data in a meaningful way that allows us to act on it almost as if we had sensed it personally.
Now, this gets more interesting when we generate full pictures of things we cannot see. A great example of this is with an MRI (Magnetic Resonance Imaging). Better than the bird's magnetoreception, an MRI allows us to look inside of a person, generally for medical reasons. The below image uses magnets to show us a picture via the EM that our eyes see, but it also has the added benefit that the picture is an fMRI showing an added layer of information (the colored spots) which we can do because we use technology to combine all the data into an image in the format we desire.
If you look at the picture below, you will be doing the same thing we are talking about. By observing the picture below, you are looking inside someone's brain by "seeing" magnetism even though you have no biological way to do.
Image public domain courtesy Wikipedia at same link as above
There are other cool images we could dig up that do similar things. I wanted to include some of x-ray visuals, microwave/radio-wave visuals, and the like because there are cool instances of those, but those are technically EM radiation, just not the wavelengths our eyes detect, so I'll forego that here. You can use Google images to turn up plenty of them, especially for astronomy.
Now here's how they do it
Now let's bring this all back around to our dolphins of Dearth example case.
As you pointed out, the printing press may have developed differently. Yes, that is likely. As you suggest, something more like braille is likely. For creatures primarily dependent on audio, audio recordings would also be likely. A phonograph cylinder is a device which can be used to record and playback audio, and it does not require any electrical components; it can also be made using very basic mechanical components.
There are simple designs which are easy to create; here is a link to one you can buy which records to and plays from a wax candle. I once saw a TV show where a small team (3-5 people, if I recall) was left on an island with limited resources and were given objectives they needed to accomplish, including documenting wildlife; one of the guys used wood and wax to create a recording cylinder - they recorded bird songs with it. It was dumb simple. Your creatures can do similar, and you can use a playback to record another cylinder, though the quality will degrade quickly. Every time you want to re-boost your quality, you would need to recite the recording again, preferably in the presence of a room full of recorders, then distribute those to remote re-recording centers. Also note that sound travels much easier through water, so in my specific example of dolphins sound will travel easily and far. Phonographs are their printing presses; slightly less efficient but they will get the job done.
After discovering electricity (Doesn't require light or modern technologies), they realize that something keeps interfering with it. While experimenting with their electronics, they discover that electric signals in some conductors produces interference with other conductors. This can take many forms but they all amount to the same thing; we get this phenomenon in devices as simple as a wire carrying the signal from a microphone to a speaker (our dolphins likely figured out microphones and speakers much sooner than we did; it's their primary sense after all), and in that case you will literally hear the interference. A bit more on electricity further below.
And this interference leads to...
And finally, EM detection (aka "seeing light")
Some bright dolphin comes along and decides to deliberately cause an electrical "interference" to be detected remotely for the express purpose of wireless transmission, and thus the blind dolphins' radio technology is born. They do not even understand light yet, nor do they have any idea why this works since they do not understand EM. They will, however, continue to experiment and progress until they have figured it out, much the same way we have for energies and forces that we can only measure with devices.
As soon as the blind, intelligent dolphins realize they can use their radios as radar, they build the biggest ones they can and point them where they cannot go: up. They find an empty expanse in the sky. Disappointing. "What if we keep building bigger?" some ask, "We might find something way far out, like millions of miles out!" "That's absurd," some will say, but eventually it will be done and other planets will be detected. So begins radio astronomy for our blind, intelligent dolphins, and they are surveying space.
Obviously the general populace wants in on this action, so their scientists invent helmets which fit them and include a surround-sound echolocation system to transform the EM data into audio data so that they can all see it in their natural sensory format.
There is another point you may have thought by now: What about detecting the energy put out by the other planets, and stars etc. for that matter? They will undoubtedly, and soon, realize that they can "see" even without the radar using passive radio detection, which might come before the radar detection of other planets mentioned above, or it might come after, depending on the frequencies they are using. Either way, they will soon see everything. We have come full circle and seen the steps they would go through.
Disclaimer (Handwavium and more on electricity)
The only hand-waving I did was "and they discover electricity," but that's not even a stretch since humans started using electricity thousands of years ago for electroplating; maybe some people understood what was going on, maybe not, but we know early humans stumbled into electricity at the very least and knew how to make a battery and use it. I don't know how they discovered it either; I just know they did, so this might not actually be hand-waving after all. As pointed out in the comment by @Mormacil, dolphins are likely to have a better up-close-and-personal demonstration of electricity than other creatures because there are marine creatures capable of generating and using electricity such as electric eels. Perhaps these dolphins even farm electric eels to use as their generators.
As you said yourself, computers as we know them are reliant on sight. The original computers and their output did not utilize monitors as we know them. Their input was not with keyboards, and their output was not by light. So this issue kind of resolves itself. I imagine early vacuum tube computers could have been attached to the audio recording devices mentioned above to provide output even easier than the paper printing that some of our early computers used, so the output device is already covered and likely invented before computers and can interface easily with our original human computers. Input might be more of a concern; my example of dolphins for example, hopefully they have better graspers, or maybe they can use audio for input as well (that could indeed be translated the other way from mechanical audio playback into the mechanical early computers). Also note that there were technically ancient computers too, even more advanced than the abacus, and some early computers even controlled devices such as this computer-controlled artificial lion from the 1400s and there were humanoid robots too. Computer technology, even computer science theory, is actually older than the electronic computer as we know it.
Now DASA (Dolphin Aeronautic and Space Administration) uses the telescopes from above, possibly in conjunction with computers (whether electronic or mechanical), and have made a major discovery; DASA has released a publication about the third planet from Sol possibly having large oceans of water. These dolphins are looking at Sol wondering if there really could be intelligent life there, or anywhere else in the universe for that matter, and we have come to the point at which our young dolphin of planet Dearth asks their worldbuilding.stackexchange.dearthnet question that I led with at the beginning.