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AtariLeaf

Strange first boot harmony issue

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So I've noticed in the last few days that after using it the first time in a day or even after a few hours the harmony just shows lines or flickering garbage on the screen. Not like a bad TIA or anything like that but like the garbage from a cart with dirty contacts.

 

After immediately turning it off and on again it's fine. Just first use after a day. I wish I had the foresight to take a pic but I'll try tomorrow or later today if it happens again. Any ideas?

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It could be dirty contacts.

 

On 1/30/2017 at 8:29 PM, SpiceWare said:

Good idea, I've noticed I need to clean my Harmony's contacts every few months. Been a while, so just did - it was quite dirty:

post-3056-0-15751300-1485829420_thumb.jpg

 

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First I wear glasses 😉😂

 

Second this cart is brand new. Perhaps cleaning the junior slot itself will help. It's just strange that its first time only. 

 

I'm going to the gym for a couple hours. I'll see if I can reproduce it this evening and snap a pic

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So coming back after a few hours it did it again. First time only. Every subsequent on/off is completely normal. It's not a time issue either. I can turn it on and off immediately and it's fine after that first boot after sitting for a few hours

 

This is an unmodded junior btw, my daily driver. Tried it on an h6 no issue

 

 

20200126_191002.jpg

Edited by AtariLeaf

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Failing power regulator in the jr maybe? Or possibly a cap issue.

 

Mitch

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Maybe. Wouldn't it be a more consistent issue if there was a failing component? I can literally turn it on and see the screen above and a second later turn it off and on and it's fine

 

I should mention the first week I had the encore this didn't happen, just in the last 4 or 5 days. This doesn't happen with any other cart including some beefier homebrews like draconian or mappy

Edited by AtariLeaf

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Sounds like it's pretty consistent to me. Turn off, then turn on immediately to get it working. What's not consistent about that activity?

 

Might have something to do with a component falling out of spec, something that can't handle peak current before breaking down. 2 whammies does the trick!

 

Encore is more beefier because it has to power a card reader and a card.. No?

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I meant consistent as in more than just the initial boot. Turning it back off and on again in a second seems to me too fast for an out of spec component to suddenly be in spec. I can check the voltage regulator tonight. I'm no expert but I would have thought the cart itself or maybe even the micro sd card would be the culprit

 

So just now as an experiment, I turned on the junior but this time put my Mappy cart in, no problem, popped it out and put the harmony in, no problem, it appeared normally no glitch so take that for what it's worth. If the harmony is the first thing I use, glitch. If it's another cart then harmony no glitch. Odd. I'm hoping @batari might chime in with an idea 

Edited by AtariLeaf

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My vote is regulator and/or capacitors. Something isn't handling the in-rush current I bet. Or pushing enough of it in.

 

An equivalent analogy would be trying to push a heavy box. You might need a running start and crash into it to get it moving, and do it again to keep it moving. Most things electrical and electronic appear as dead shorts (to their power supply) till they start running.

 

A modern x86 microprocessor can present itself as a 300-amp short circuit till its clocks get running. Which thankfully happens in nanoseconds, otherwise BOOM!!

 

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Well I can replace the regulator easy enough. I should have main caps too.

 

Still seems odd that one literal second is enough of a running start to push that heavy box

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22 minutes ago, AtariLeaf said:

Well I can replace the regulator easy enough. I should have main caps too.

 

Still seems odd that one literal second is enough of a running start to push that heavy box


A second can be a very long time in the electronic world sometimes.

I am reminded way, way..... waaaayyy back to when Pentium CPU just came out and they required coolers. There was a DIY'er who had a video I watched on them.

Part of it was a demo for the people who wanted to fire up the system quick without a cooler to see if it would boot; before finishing assembling the PC.

He flipped the power switch, the monitor flashed, and he said '... and now you go buy a new CPU because that there just cooked it'.

In that instance one second was much too long.

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Tried it when I got home from work and it came up fine first time this time. I'll still replace the regulator probably on the weekend when I get some spare time. 

 

I have 1 A regulators from console5. If it's true the encore draws more power isnt it prudent for all encore owners to automatically change the stock .5 A regulators out regardless?

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I don't know how much instantaneous peak current a Harmony/Melody/Encore board can draw. I also do not know what a traditional 2K or 4K cartridge draws either. I'm too lazy to look up the parts' datasheets and calculate specs.

 

But - that instantaneous current can only last microseconds or nanoseconds, and it happens when a lot of transistors all fire off at the same time. Or if the ARM is under load or doing something "important". Now figure you got an ARM CPU, some support circuitry, and an SD card.

 

I know for fact that many SD and microSD cards ask for 80-140mA of current when conducting read operations. That's .08 to .14 Amps taken away from the regulator right there.

 

Long story short is that a regulator and its ripple-reducing capacitors can output 5V under little or no load. But sag and become noisy during peak load. The second oomppf from a quick power-cycle can mask that scenario.

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Does this mean NOT replacing the vr could eventually damage the console?

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Oh absolutely yes. Clean power in-spec is a top priority. It's why we have such things as regulators and capacitors and power supplies. A weak supply can cause your transistor logic to behave like a class-A amplifier so to speak. Not enough power to completely push the the transistor fully on or off.

 

If it's noisy and has ripple or hum or sags enough that the console's transistors operate more in the middle-Q as opposed to bang-bang on-or-off, sure, absolutely. Transistors run their coolest when either switched fully on or off. Saturation or cut-off. They draw the least amount of current then. They generate the least amount of heat then. And they switch positively, sharply, and smartly.

 

If they have the wrong voltage, sagging voltage, or bouncing voltage they float around middle-Q and that's like a big resistor (by design by the way) and can generate heat.

 

Situation gets bad enough something's gonna go bad.

 

---

 

An unrelated (to VCS) extreme example. I had a cheap ABIT mobo at the turn of the century. It had those cheap china crap capacitors. They got weak rather quickly. The voltage regulators got hot trying to smooth the ripple on their own. Failed. And the Pentium III 850 CPU blew its heatsink off. Metal blobs flew in the air. And I remember it to this day like it was yesterday. I was so fucking pissed. 850MHz was big expensive stuff then.

 

That's a high current example. A VCS, being much more low-power, would likely develop hot chips. Hot enough to the point they start smelling. Then they'd go pop, or just short and refuse to work. Hopefully your regulator would overheat and blow open, thus shutting everything down. Seen it happen both ways.

 

 

Edited by Keatah
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5 hours ago, AtariLeaf said:

Tried it when I got home from work and it came up fine first time this time. I'll still replace the regulator probably on the weekend when I get some spare time. 

 

I have 1 A regulators from console5. If it's true the encore draws more power isnt it prudent for all encore owners to automatically change the stock .5 A regulators out regardless?

To me the issue looks like your console is doing many false starts in the first milliseconds after the power switch is flipped before starting up for good. From our testing, all consoles do several false starts before starting for good, but this usually takes a few milliseconds at most. In your case it might be happening for far too long. On a normal cart this would be of no consequence as each start would hit the reset vectors, restarting the cart too, which clears the TIA. However, Harmony has a multi-stage boot process, so if the console goes down during the second stage (or later) of the boot process and the Harmony stays awake the whole time, this can happen.

 

If your caps are shot, you could certainly see such transitory spikes well into the hundreds of milliseconds. I think a dirty power switch or dirty contacts on the 2600 or Harmony could cause the same.

 

I did some testing a while ago using a digital power supply that showed instantaneous voltage and current. While the Harmony did use more current at times, if I recall right, the difference was not great. I want to say it was never more than 100ma more than a typical cartridge. I am sure this is still well within spec of the stock regulator and PSU and with a normally-functioning console it should work fine.

 

Let us know if you do anything with your console and if it helps.

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11 minutes ago, batari said:

To me the issue looks like your console is doing many false starts in the first milliseconds after the power switch is flipped before starting up for good. From our testing, all consoles do several false starts before starting for good, but this usually takes a few milliseconds at most. In your case it might be happening for far too long. On a normal cart this would be of no consequence as each start would hit the reset vectors, restarting the cart too, which clears the TIA. However, Harmony has a multi-stage boot process, so if the console goes down during the second stage (or later) of the boot process and the Harmony stays awake the whole time, this can happen.

 

If your caps are shot, you could certainly see such transitory spikes well into the hundreds of milliseconds. I think a dirty power switch or dirty contacts on the 2600 or Harmony could cause the same.

 

I did some testing a while ago using a digital power supply that showed instantaneous voltage and current. While the Harmony did use more current at times, if I recall right, the difference was not great. I want to say it was never more than 100ma more than a typical cartridge. I am sure this is still well within spec of the stock regulator and PSU and with a normally-functioning console it should work fine.

 

Let us know if you do anything with your console and if it helps.

Thanks for your reply. It seemed fine today. I'll replace the vr and the main caps this weekend and report back.

 

Have you ever seen the screen I posted in your testing over the years?

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54 minutes ago, AtariLeaf said:

Thanks for your reply. It seemed fine today. I'll replace the vr and the main caps this weekend and report back.

 

Have you ever seen the screen I posted in your testing over the years?

I have seen a screen like that, yes, it's come up in testing once in a while. In my case a good cleaning of the cart slot pretty much always seems to fix it, but it can have other causes.

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I'll give the cart slot a good cleaning too. Probably a good idea in general 😁

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Bad comes to worse and the simple things don't fix it. There is a basic 390x transistor in the reset circuit. I've replaced them in the past to fix consoles that wouldn't reset unless "warmed up".

 

In troubleshooting, start with the basics and dive deeper as needed.

 

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Well let's start with the simple - clean the cart slot, check and replace the vr, main caps. Then go from there. I trust bataris experience. Oh and I do acknowledge that Keatah has a tremendous amount of electronics knowledge so thanks for your help

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Posted (edited)

I finally had a chance to open this junior up. I didnt replace anything but the vr is giving me 11.03 v in and 5.01 out so those are good numbers correct? Is it still recommended to swap it out? The harmony cart has only glitched on me once at first boot in the last few weeks on this junior so it's mostly good

 

Also something odd with frogs and flies. A line of pixels near the right side of the screen in the trees from top to bottom flicks like they are blinking on and off with each left joystick button press. I dont know if it's a related hardware issue or not. It's a rev F btw

 

 

Edited by AtariLeaf

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