Revo_Emag
Posts: 5
Joined: 06 Jan 2019, 04:36

Super Grafx issues?

06 Jan 2019, 07:28

I'm seeing some issues with corrupted graphics, occasional boot failures and crashes with the SSDS3 (rev 3, FW v1.02) on my Super Grafx only when it's in SGX mode (I). In the SSDS3 menu it is random characters and graphical elements scattered over the screen. I can launch games, but they also suffer from graphical anomalies and crashes. If I switch to compatibility mode (II) there are no graphical menu problems at all and games play fine, but obviously I lose SGX. In case it maters for this issues this machine is region switch modded so HuC6280 pin 29 is grounded. Also the problem seems more pronounced when set to in TG16 region mode. Likewise in compatibility mode (II) the SSDS3 works perfectly fine in both TG16 or PCE region modes. The SGX also plays PCE and SGX HuCard games without any issues in both mode I and II.

*edit* Using a 3rd party 9v 1.2A power supply and HD Retrovision video cable. Same issue if trigger is on or off.

I also own a PCE Core Grafx with the identical region switch mod installed and it has no problems at all with the SSDS3. So I'm confident the SSDS3 unit is fine, but there is something not working with SGX mode.

Any ideas or is this a known issue?

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Todd
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Re: Super Grafx issues?

07 Jan 2019, 02:50

There are no known issues with Supergrafx compatibility.

It really sounds like to me something is up with your region mod.

Can it be removed or disabled?

Mobiusstriptech
Posts: 155
Joined: 13 Apr 2018, 15:41

Re: Super Grafx issues?

07 Jan 2019, 06:20

What region mod is it? Any pictures of the work?

Revo_Emag
Posts: 5
Joined: 06 Jan 2019, 04:36

Re: Super Grafx issues?

07 Jan 2019, 22:32

It's Game-Tech's region mod and I've installed these myself (along with many other mods for various systems). I don't have pics of it at the moment. I'd have to take it apart to get some. Removing the mod is possible, but not really worth the work and risk IMO to get the 3 SGX titles I don't own on HuCards running :D. Another interesting thing with my SGX is it has a factory(?) bodge wire instilled on the bottom RF film going to the EXP bus on a pin kind of centrally located IIRC (so not audio or video output related). I assume it's factory, but I can't be certain although it does look to have been done very professionally. Not sure if that's typical either.

The mod has been in the SGX machine for several months and I have a Core Grafx and a Turbo Duo both with the same mod installed for even longer all installed by me. All these systems work perfectly with HuCards and the SGX HuCards I own work perfectly as well. I'm 99% confident that the mods are working fine, but yes there's always a chance something's up with it. I just got the SSDS3 last month and only tried the SGX over the Holiday.

I'll say that to me this is only a very minor inconvenience since the SSDS3 works perfectly on the Core Grafx (where I'll probably use it 99% of the time anyway) and the SGX when in compatibility mode (II).

I'll try and post some pics in the next few days if I have time. Thanks guys!

Mobiusstriptech
Posts: 155
Joined: 13 Apr 2018, 15:41

Re: Super Grafx issues?

07 Jan 2019, 23:39

Every SuperGrafx has that wire. It is a factory mod. I wasn't implying that your mods were installed incorrectly or that it was poorly done. It's beneficial to know as much as possible when trying to diagnose an issue that others aren't having. Knowing that it is a game-tech region mod is helpful because it is very common. How it operates in Duo consoles isn't terribly helpful though.

The main reason I asked about install pictures is because we don't know if the issue is in any way related to where power is being drawn from or how the switch is routed. While it should theoretically have nothing to do with your issues, other SuperGrafx consoles are not describing similar issues. I myself have a SuperGrafx and currently have 2 additional SuperGrafx units here that do not experience the issues you mention.

I genuinely hope that your issue can be narrowed down and corrected. I have a number of consoles here for testing and will try adding region mods to a few to see if I can replicate your issues.

Revo_Emag
Posts: 5
Joined: 06 Jan 2019, 04:36

Re: Super Grafx issues?

09 Jan 2019, 06:07

Thanks for looking into this too :!: If you can find something for me to try I'd be happy to give it a go. If not, no worries I'm satisfied the SSDS3 works 100% fine and the problem is likely something with this SGX. Out of curiosity, which group of RAM chips and HuC6270 gets disabled in mode II?

Here are some pics and results of a few quick tests. Let me know if you think any other specific views could also be of help.
1. Disconnected VCC and GND wires from the op amp chip that powers the RGB amp board. No difference.
2. Tested removing the ground on pin29 of the C6280 for the region mod. Made no difference other than force JPN region.
3. Disconnected power from region mod. Made no difference.
These 3 things were done in that order and retested each time (so 1, then 1&2, then 1&2&3). I still got the graphical glitches each time only in SGX mode (I). That's as realistically close to stock I can get without actually fully removing the mods.

Splash logo and menu example (it's never exactly the same twice):
Image
Image
[I can actually still load games like this and some run seemingly okay (*not played enough to know for sure) while others show obvious graphical glitches or crash]

Board and mod pics:
Image
[mod vcc is direct from 5v regulator output, BRW wires to physical switch]
[RGB amp is pulling VCC&GND from the corresponding legs on the dual op amp, Y and O wires, and CsRGB from HuC6260]
[Jailbar fix was done on the bottom side too, but I can't imagine that would have anything to do with this issue.]

5v reg power tapped on OUT (right) pin in this view:
Image

Closeup on region board:
Image

HuC6280 Pin 29 ground
Image
[Simply bridged to pin 30]

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neodev
Posts: 217
Joined: 09 Apr 2018, 14:47

Re: Super Grafx issues?

09 Jan 2019, 08:11

Just a quick test. Can you test an actual hucard game, (having the ssds3 connected, then with it disconnected) and the the same game loaded by the ssds3? These glitched look like a videl chip issue. Compatibility mode disables the 2nd chip and the color mixer.

Mobiusstriptech
Posts: 155
Joined: 13 Apr 2018, 15:41

Re: Super Grafx issues?

09 Jan 2019, 18:59

That's obviously the newest rev of both Voultars board and the Duo region mod. I don't suppose this was ever tested before you did the mods?

Revo_Emag
Posts: 5
Joined: 06 Jan 2019, 04:36

Re: Super Grafx issues?

09 Jan 2019, 23:47

The region mod was installed around late October and Voultar's CsRGB mod was done late December right after I got the SSDS3. So, no this SGX never got tested on an SSDS3 pre-region modding which is unfortunate, and the problem existed pre-RGB mod. Prior to any modding the SGX was tested with HuCard games just fine on stock composite video and also with an EXP bus RGB adapter (clone of the db Elec. booster). Yesterday I disconnected the CsRGB board's power and tested on composite and the glitched graphics still only happen in SGX mode (I) with the SSDS3 installed.

Even now all original HuCards including Daimakaimura, Battle Ace, and Darius Plus play without issue (without the SSDS3 installed) in SGX mode (I). And to reiterate, the SSDS3 works 100% on this SGX in compat mode (II). I will test again with the SSDS3 still in the EXP bus and running the game off HuCard when i can.

It's just a hunch, but I'm feeling like the 2nd HuC6270 or it's RAM chips are somehow involved here. Like one of them has a fault that's somehow sensitive to using the SSDS3. I'm not up for de-soldering those and swapping their positions mainly because I lack the proper tools for that, but I'm really curious if that was done if the problem would then appear in compat mode (II) on this SGX.

Revo_Emag
Posts: 5
Joined: 06 Jan 2019, 04:36

Re: Super Grafx issues?

12 Jan 2019, 08:00

Thanks guys for trying to help out! I've found the source of my issue (or as close as I can get to it). It's either the HuC6280 or the board and/or passives immediately nearby. While testing Daimakaimura on HuCard vs. SSDS3 I noticed that as I used the system for a long time, 1hr+, the glitchy graphics suddenly went away after power cycling the SGX and SSDS3. It came back only after I stopped for a while and the system cooled down a bit. Then I knew it was probably a heat related fault. I tried reflowing the pins on all the the chips and the EXP bus terminal in case there was a bad connection, but the behavior remained. So I tried heating individual chips until I found the one that is causing it.

If I preheat the HuC6280 the problem goes away temporarily and in a repeatable fashion. It doesn't have to be all that warm either, estimating maybe a little more than 40C by touch. I just used a small incandescent flashlight bulb like a weak IR spot heater directly above the chip. I still can't explain why it only does this with the SSDS3 though. If I play any HuCard with the SSDS3 plugged in there is no problem at all (even when cold) while the SSDS3 is powered on and outputting RGB video.

Yes, it's weird. Maybe you have more insight as to why?

I'm calling it done and not going to worry about it any further.

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