[X] My Assistant

Remotely helped the friend i got a Saturn for to diagnose a dead audio channel on the headphone jack of their own Genesis.

Was very refreshing to have someone who trusted me enough to start poking at components on a circuit board while it was powered on. We eventually determined by looking at schematics, and with a little testing on my personal (working) system that there was a dead capacitor after the op amp just prior to the headphone output that seems to have failed shorted (but without physical symptoms).

Hoping that failing short hasn't damaged the op-amp (which might be a bit hard for a novice to desolder). Probably hasn't, just because of this specific capacitor's role as a decoupler, but we'll have to see. I was able to replicate their symptoms by (momentarily) bridging the legs of the same capacitor on my own system and the op amp continued working afterwards.

The mono sound out the back of the console still carries both channels' signals since it goes through a separate buffer and amp and separate capacitors.

This post has been edited by dragontamer8740: Apr 23 2023, 09:14

[apnews.com] https://apnews.com/article/russia-ukraine-b...ccef16c233013a7
*image*

The text seems to be about a legit event (unless the other source I saw got fooled by a fake news), but the image certainly doesn't give a credible first impression (IMG:[invalid] style_emoticons/default/rolleyes.gif)

Just stumbled onto two more new old stock 14" CRT screens in my town, both with s-video inputs.

Each for half what i just paid for mine. And with more advanced settings available. :p

So I bought them.

I need to get rid of some CRT's but I can't decide which ones. Definitely keeping the RGB ones, since those are rather rare birds in America (at TV resolutions; not PC monitors). but I like all of them.

This post has been edited by dragontamer8740: Apr 26 2023, 10:14

The problem with CRT is that I'd want a high end big one and that would be hard to move around and expensive.

I'd probably also have to learn how to do the maintenance. When the local repair store closed the quotes to fix some of the tvs went to the moon.

The problem with CRT is that I'd want a high end big one and that would be hard to move around and expensive.

I'd probably also have to learn how to do the maintenance. When the local repair store closed the quotes to fix some of the tvs went to the moon.

My 20" Sony PVM (PVM-20L5) does need a new flyback transformer, I suspect.
Works for now, but I try not to mess with it.

For weight, the heaviest I've lifted was a 20" 40kg Sony one. But non-Sony pro sets are significantly lighter than that - I suspect on account of the aperture grille weight or something.

I have a 27" consumer set with component inputs which is also pretty nice overall, but definitely not "pro."

I find that unless playing with others I am quite happy with a 13" or 14" set on my desk or on a coffee table.

You can also daisy chain most pro-type monitors together to give multiple players their own screens.

20" RGB sets like mine are nearly unobtainium in current year, it seems.
So are flyback transformers unfortunately.

I could always try to get a 14L5's main board and steal its flyback. They appear to be identical. But the 14L5 is still nearly $1k on ebay right now. For a 14" monitor. So I have to wait for a broken one to show up where I am pretty sure the problem is not the flyback.

I can't find the original flyback transformer anywhere.

BTW, SMPTE-C phosphor screens are nowhere near as bright as P-22 ones. The very highest end pro gear usually uses SMPTE-C, but it's nothing like what you expect when playing a game in normal lighting conditions. In a totally dark room it looks fine. Otherwise the contrast is lacking. I recommend a P-22 tube.

If you can get flyback transformers (or if your problem is something other than the flyback or tube), fixing CRT TV's isn't hard. I remember I was able to remotely diagnose someone's issue based on a crappy schematic and a symptom about eight years ago (guessed cracked solder on a 7812 12V voltage regulator was the cause of them not having synchronization (looking scranbled, like horizontal hold dial was fucked up) and the power LED not coming on but the set otherwise working and showing colors).

The worst thing apart from high voltages in there is correctly adjusting a deflection yoke coil (if you need to swap that), to keep the colors pure and convergence good on color sets. And that's just a massive pain in the ass rather than actually requiring special skills. Lots of trial and error unless you have some very expensive equipment to automate it. Equipment that was already expensive when it was new.

You can go crazy high end with CRT's, but I honestly think the best look for video games is at around 400 TVL of resolution (for reference, the 20L5 is 800 TVL, and the highest i've ever seen for sale is 1000 TVL. TVL is a measure of horizontal resolution capability). Screens with that resolution have subtle scan line effects like old arcade monitors did (arcade monitors almost never used extremely high end tubes; the usually used mid-to-high-end consumer market tubes with custom electronics to allow directly controlling the tube via RGB signals). I'd rather have a consumer/prosumer set with decent image stabilization (bloom countering) than a super expensive top of the line one, as long as the consumer one had something better than composite available.

--------

If you do go pro, I'd suggest a tri-dot pattern monitor rather than a trinitron/aperture grille one. the dampening wires in the AG do show up on the screen as slight dark lines, and tri-dots provide the a certain smoothness that AG doesn't at similar TVL counts. Olympus, JVC/Panasonic/Matsushita/National, Ikegami, Conrac (american company. actually what the 'C' in 'SMPTE-C' stands for), and Sanyo all made good ones over the years. Others did, too.

TL;DR:
I have some very high end pro CRT's, and they are overrated. Yes, they are nice, but if you have at least S-video you are getting 95% of the experience. And arguably something more like what the games were designed and marketed on. The RGB screens they used for manual screenshots and stuff in the 80s were not 1000TVL.

You do have to mod the mega drive to get s-video out though. Slightly annoying. But one of the easiest mods ever. About $10 of parts at most when bought in single quantity.

If you get a CRT and need to repair it I'd be happy to give pointers. I don't want the art to be lost.

This post has been edited by dragontamer8740: Apr 27 2023, 00:51

Why did I stop building PCs for people?

They call me like a decade later for tech support, often not even the same computer.

speaking of CRTs I'm very tempted to get one of the small all in one units with the radio receiver. theres a couple around local thrift stores.
something similar to this, the ones with the receiver dial at the side (just saw it in a video I was watching not this exact quality somy one):


I'd mostly have it in the living room for messing around with, maybe as display for my stereo which only has composite out. didnt really need a tv as I dont watch it anymore so currently theres no tv there.
no clue if they're any decent as I either dont remember ever seeing one or they just werent around.

This post has been edited by cate_chan: Apr 27 2023, 13:56

speaking of CRTs I'm very tempted to get one of the small all in one units with the radio receiver. theres a couple around local thrift stores.
something similar to this, the ones with the receiver dial at the side (just saw it in a video I was watching not this exact quality somy one):


I'd mostly have it in the living room for messing around with, maybe as display for my stereo which only has composite out. didnt really need a tv as I dont watch it anymore so currently theres no tv there.
no clue if they're any decent as I either dont remember ever seeing one or they just werent around.

I know I used to have one of those; not sure if I still do.

I forget if the one I had had a composite input or was RF only.

They're usually monochrome.

I would like to take a moment to recognize a well-written datasheet.

[files.catbox.moe] https://files.catbox.moe/iqicry.pdf

I got another NOS CRT monitor (a CCTV screen from Honeywell, but actually appears to have been made by or for Hi-Tron); this one has no service manual and I was trying to figure out how to get white balance adjusted on it since there are zero trimpots inside (and I can't figure out a way to access any service menu).

I'm not very happy about having to do it this way, but I am relieved that the datasheet for the main video processing chip in the TV exists, is available, and is in English. Much better than a certain Toshiba TV I've worked on before.

Looks like I'm going to have a project intercepting and manipulating I2C bus signals soon. I already found a nice tapping point for the bus on the circuit board (two jumper wires that I can cut and solder or clip to).

There is one annoying problem still - a sort of shimmering effect on some screens while playing games on it. Feels like an unstable/poor horizontal sync decoding problem. I see a few things that I might potentially be able to do to resolve them in software, but we'll have to see.

EDIT: ripple went away. Wonder if it was because of something else on the power grid introducing ripple, or something.

Looks like I will also be able to RGB mod this one; thankfully the datasheet for this chip goes into some pretty good detail about how to use it to add an analogue RGB input.

There's a Samsung tube in it.

This post has been edited by dragontamer8740: Apr 30 2023, 00:18

After EasyDiffusion stopped working for an unknown reason (something must have shut down without logging in the console, thus no explanation), I saw that my Internet got broken.
I thought I may have corrupted the memory/GPU or whatever by overloading it all, so I did a full system reboot but it didn't fix it.
I finally found why Internet went wrong: one filter list in ADBlock Plus went crazy, and was blocking all images, css and other stuff.
While writing this, I thought of reenabling it long enough to show off what it look like when it's enabled, but having it disabled for a while apparently fixed things, so I can't demonstrate anymore lol.

Found a genlock for my Amiga.

Planning to watch some laserdiscs with subtitles courtesy of it. Will probably peek inside the genlock and see if I think it's feasible/easy enough to S-Video mod.


Unrelated: I just popped by another forum that used to be a cozy spot like this place is - they'd switched from an old version of vBulletin to MyBB and the result is a cold, sterile feeling "modern web" environment. Makes me uncomfortable sticking around on those forums because I remember how things used to be.

I mean, it's great that they moved to a FOSS solution. It's just too bad it suffers from modern web look and feel (desaturated, flat, blue).
Still far from the worst forum I've seen. I've been on some that use javascript to tell you when someone's replied in real time and that do their damnedest to prevent me from getting a plaintext field to write my BBCode in.
I am kind of amazed that this Invision board still works, but I guess that's just because I'm so used to people ditching things. I wonder if it's going to hit problems from the sheer weight of stuff on it soon, or how long it'll last.

There's probably only one other board this old that I still frequent, and it's full of people who grew up on Commodore 64's, so I guess they know what they like. I appreciate them. That one runs a version of PhpBB from 2007.
I believe we're using Invision Power Board 2.3.6 or something on here. Maybe with some tweaking around the edges.

Was going through web.archive.org earlier today trawling for JACOsub subtitle files to use with my amiga, came across a few sites that used all-caps HTML with statically sized tables for layout. Th site actually looked really cozy to me, even if tables are evil or something.

(Yes, I know Invision makes use of plenty of tables).

This post has been edited by dragontamer8740: May 1 2023, 02:54

Got the genlock in mail today; took it apart, inspected the board. looked fine. Took pictures. Then turned it on and it started sizzling almost immediately.

Amiga seems to have escaped unharmed, but I sure ain't happy about it.

Buying some transistors, resistors (the resistors are what burned, but probably because of some other part failing I'd guess), capacitors, and diodes to replace the parts in the area surrounding the burned bits. Also ordered another cheap genlock of the same model to see if I can figure out what's wrong or at least have a spare if my repair attempt fails.

If the second one dies the same way, I'll assume my Amiga itself is what's killing them.

Wonder if I could run a PAL amiga that's been 60Hz modded with color via a genlock. Not done that yet; I used my NTSC one.

Not feasible/easy to S-Video mod, btw. All the important chips have had their markings rubbed/sanded off because the designers were assholes.

If I can get a working one I might poke around with an oscilloscope probe and see if I can locate anywhere that separated Y/C signals are exposed.

This post has been edited by dragontamer8740: May 5 2023, 05:27

Got the genlock in mail today; took it apart, inspected the board. looked fine. Took pictures. Then turned it on and it started sizzling almost immediately.

rip. is it burned beyond repair or salvageable?

rip. is it burned beyond repair or salvageable?

Potentially salvageable.

Handful of resistors are burned (maybe 5 visibly burned); will need to replace those. Will also replace the nearby transistors and diodes. There are maybe three electrolytic caps on the board which I might as well also replace. Axial lead, unfortunately, but eh. I'll make it work.

I don't see burned traces or anything as of now.

No scorch marks on the PCB itself that I can see. Unsure if the IC's lived but I suspect based on pure intuition that they did.

The transistors are commodity enough that I have a handful of the correct variety already (2N3906). There are also some 3904's IIRC.

I did see some video on my screen for a moment before it started smoking, so that's why I think there's a chance it's fixable.

This post has been edited by dragontamer8740: May 7 2023, 08:45

Random program manager: How would we go about adding Stable Diffusion into our [firmware thing that does a very specific data splitting]?
Me: *Looks at tech lead with a confused face*
Tech lead: *Looks at me with an even more confused face*
Me: You want to... add AI/ML to help process data...?
Random program manager: *points to me* Yes! That!

Both tech lead and I mentally facepalm.

The show I was watching somehow made me thinks of experiments to try to create "a compatibility with a technologically-generated telekinesy/telepathy" (rather than creating the technology itself or even directly telekinesy/telepathy, though it would be funny if it happened naturally).
Damn cursed world where if means to get in touch with scientists to propose or participate in experiments exist at all, they're too far from user-friendliness to be really available to the general public (IMG:[invalid] style_emoticons/default/sad.gif)

Got my second genlock in the mail; this one actually works.

Have a picture of Nei from Phantasy Star II eating a floppy disk. Drawn as an overlay with deluxe paint.
Blurriness isn't the genlock's fault; I'm overlaying it on composite video from a model 1 genesis, and model 1 genesis composite video quality sucks.
[postimg.cc] (IMG:[i.postimg.cc] https://i.postimg.cc/q7TCkF5z/genlock-amiga-med.png)

I guess it's also a crude way to get a "desktop background" on the Amiga.

[postimg.cc] (IMG:[i.postimg.cc] https://i.postimg.cc/JhsjnF38/mpv-shot0108.png)

This post has been edited by dragontamer8740: May 9 2023, 01:09

My phone had a pop up notice telling me to go outside and touch grass...\

edit:


AMD Engineers: Internal over current protection is glitching we will have to issue a micro code update later. Don't worry motherboards also have protection measures so it will be fine. Send it.

ASUS Engineers: Our motherboard's over current protection is not working we will have to issue a bios update later. Don't worry the AMD cpu has internal over current protection measures so it will be fine. Send it.


Users: Why is my chip on fire?


Going through tech posts, seems be because they have work arounds for DDR5 voltage bugs. Some DDR5 kits PMIC circuits are leading to voltage sometimes cycling to the maximum bios value (1.7 to 1.8 volts), this can occur more frequently with new AMD EXPO setting. If you have your 7000 series CPU set to auto voltages in bios, when the memory voltage spikes it can spike a bunch of other voltages and the CPU / MOBO isn't stopping it, SOC voltage can go to the moon which is leading to melting CPUs.

AMD still has the bug of user values still sometimes being ignored on some Mobos.

The current work around is setting the voltages to safe levels and removing the higher values but the problem is still persisting.

Intel's work around was just not letting your PC boot if the issue was detected.

This post has been edited by EsotericSatire: May 12 2023, 09:22

4090s power connectors are still melting.

Not plugging in the cables all the way lead rapidly to the connector shorting and melting.

However even cards where the cables are inserted correctly and with the 90 degree cable mod adapter are now starting to fail months later.

I guess they managed to convince people it was user error for long enough to sell the cards.

work