Author Topic: Turbografx 16 graphic glitches?  (Read 1015 times)

Thrashingdeath96

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Turbografx 16 graphic glitches?
« on: September 02, 2023, 05:58:45 PM »
Hey all! I've tried searching everywhere for a answer (google,reddit) but I can't seem to find a clear answer why my turbo is doing this. It is region modded and recapped, the thing is it worked after recapping it but I tried to reflow the ext connector pins with hot air because my edfx wouldn't work. Is it possible that I fried something?

https://imgur.com/a/i87ii62
« Last Edit: September 02, 2023, 06:01:06 PM by Thrashingdeath96 »

majors

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Re: Turbografx 16 graphic glitches?
« Reply #1 on: September 07, 2023, 10:35:56 AM »
Looks like a special "acid" edition of a Turbo...

Sorry for not having a technical answer for ya, hopefully another member will chime in. Can you run the console without the Everdrive FX? (run it RF to test if the console is running proper)
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Thrashingdeath96

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Re: Turbografx 16 graphic glitches?
« Reply #2 on: September 07, 2023, 01:08:51 PM »
It only outputs video through rf

Keith Courage

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Re: Turbografx 16 graphic glitches?
« Reply #3 on: September 08, 2023, 07:27:37 PM »
So no AV out? Just RF? That's weird. What did you use to test composite out?

Thrashingdeath96

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Re: Turbografx 16 graphic glitches?
« Reply #4 on: September 08, 2023, 08:12:19 PM »
I had one of those hyperkin av adapters. Im wondering if it fried my system because my edfx doesn't work on the expansion port.

Thrashingdeath96

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Re: Turbografx 16 graphic glitches?
« Reply #5 on: September 10, 2023, 06:06:09 PM »
Reflowed every chip on the board and the expansion port. Still no change sadly. I wonder why the expansion port isn't working but the rf is. I've been digging around and people are suggesting the ram might be the issue HSRM2264LM10 and HSRM20256LM12. Apparently there are modern replacements of these but I'm not sure where to find them. Does anyone know where to get them?

Keith Courage

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Re: Turbografx 16 graphic glitches?
« Reply #6 on: September 12, 2023, 04:02:34 PM »
Sounds to me like you could have a faulty HU6260 chip. I would think this because of the lack of video from the expansion port.

I'd be curious to try tapping the RGB pins or Luma pin from the HU6260 to see if you get any signal.

To test Luma, simply use any RCA cable and run the positive wire to Pin 40 on the HU6260 chip, Then the ground wire to any ground on the Tg16 board. You can plug the RCA cable into composite on your TV. I'd like to know if you get any black and white image doing this. If Luma shows a picture, then you might just have to rebuild the composite circuit using the Turbo Express composite out mod.

You might get lucky and a component or components on the board that amp/mix the composite signal could be bad and it could be repaired or that composite/luma is dead but RGB is still good.

I've worked on quite a few systems where one option of video is still available and can be used that way once wired up appropriately.

Thrashingdeath96

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Re: Turbografx 16 graphic glitches?
« Reply #7 on: September 13, 2023, 06:16:03 PM »
I stripped back some composite cables I had and there was only wire >_>
 Soldered that to pin 40 on the hu6260 and I'm not getting anything.

Keith Courage

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Re: Turbografx 16 graphic glitches?
« Reply #8 on: September 13, 2023, 06:45:57 PM »
Dam. You should be getting Black and white video from the Luma pin on the HU6260 chip. Most likely the HU6260 chip is bad then.

You could always test the RGB signals if you have a RGB compatible monitor or upscaler to see if those are also dead.


Oh and just for the sake of checking, maybe make sure the Hu6260 chip is getting 5V. https://wiki.console5.com/wiki/Hu6260


Also, none of the rear expansion port pins are bent or pushed in are they?

Thrashingdeath96

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Re: Turbografx 16 graphic glitches?
« Reply #9 on: September 13, 2023, 06:51:43 PM »
One of the Pins is definitely bent but I did straighten it out

Thrashingdeath96

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Re: Turbografx 16 graphic glitches?
« Reply #10 on: September 13, 2023, 07:30:43 PM »
Tested the voltage on the hu6260 I'm getting 14v. Not sure if that's right or not

Keith Courage

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Re: Turbografx 16 graphic glitches?
« Reply #11 on: September 14, 2023, 05:47:43 PM »
14V?! That's way too high. It should be 5v. Did you test the 5V spots shown on the diagram link I posted?

I wonder if there is a component on the board that is pushing too much voltage. Trace the trace on the board that shows 14V and see where it is coming from. I suppose you should also check the 7805 voltage regulator to make sure one side shows 5V.

Thrashingdeath96

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Re: Turbografx 16 graphic glitches?
« Reply #12 on: September 14, 2023, 07:20:28 PM »
14V?! That's way too high. It should be 5v. Did you test the 5V spots shown on the diagram link I posted?

I wonder if there is a component on the board that is pushing too much voltage. Trace the trace on the board that shows 14V and see where it is coming from. I suppose you should also check the 7805 voltage regulator to make sure one side shows 5V.
I think I blew a fuse testing the voltages. Oops! I dont think i was Testing the voltage regulator correctly.

Thrashingdeath96

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Re: Turbografx 16 graphic glitches?
« Reply #13 on: September 18, 2023, 08:02:59 PM »
Well I replaced the fuse and tested the voltage regulator again properly. The left most pin is getting 11v and the right most one is getting 5v. Not sure If those are the right voltages or not.

Thrashingdeath96

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Re: Turbografx 16 graphic glitches?
« Reply #14 on: September 18, 2023, 08:20:21 PM »
I went through and tested the huc6260

57-5v
54-4.18v
50-5v
41-0.19v
36-5v
34-5v
27-5v
21-5v
16-5v
13-5v
1-5v

So a couple pins definitely aren't getting the right voltages. Bad solder joint?