Use gen2 module without NESRGB possible?

[danyboy666]

I have the version 3.1c and I can't get it to show anything other than a vertical and horizontal white line? The board i want to use is an opentendo which is 100% populated with componants i'm sure are all good. CIC, CPU and PPU all pulled from a working nes. So my question is, is there a way to hook the av module without an nesrgb mod?

[ShawMerlin]

If you do not have a RGBNES, you can still get audio out through the AV with the selector in the internal video position. This board doesn’t do any video processing so if you aren’t seeing a picture, there may be an issue elsewhere. What you can do to troubleshoot the board is look at the voltage on the top of the 5 interconnect pins. It should be 12volts or higher, then check the 2nd pin with the power switch on and it should be also 12 volts or higher. Then check the 3rd pin and you should have 5 volts on that pin. Let me know if you are able to test these points. Thanks, -Merlin Shaw

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On Saturday, January 11, 2025, dferron ***@***.***> wrote: I have the version 3.1c and I can't get it to show anything other than a vertical and horizontal white line? The board i want to use is an opentendo which is 100% populated with componants i'm sure are all good. CIC, CPU and PPU all pulled from a working nes. So my question is, is there a way to hook the av module without an nesrgb mod? — Reply to this email directly, view it on GitHub <#21>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AQZJHHWY3WYAXY2ZKN4YZF32KFEXXAVCNFSM6AAAAABVAEGT2CVHI2DSMVQWIX3LMV43ASLTON2WKOZSG44DEMBRHE3TIOA> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[danyboy666]

Alright I will let you know. I don't think it's a voltage issue I think i've narrowed down to bad ram. I have a stack of 6116 they might be the issue along with a suspected bad ppu. I have a couple sets of cpu ppu along with good ram chips. I will do some more testing tomorrow i've just finished desoldering ram sockets from a working nes pcb for testing. I'm sure it's an issue on my side thanks for your great work on this I have printed several from jlcpcb already just wanted to make sure it would work without rgb mod board. Thanks alot.

[danyboy666]

In your experience is it possible for a bad ppu to corrupt/break a ram chip? I've have a couple of brand new 6116 equivalents but all.seem to output the same lines on screen.

[ShawMerlin]

I have never seen a ram chip impacted by the PPU but anything is possible.

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On Sat, Jan 11, 2025 at 3:21 PM dferron ***@***.***> wrote: In your experience is it possible for a bad ppu to corrupt/break a ram chip? I've have a couple of brand new 6116 equivalents but all.seem to output the same lines on screen. — Reply to this email directly, view it on GitHub <#21 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AQZJHHUCOTLRFIU4HGA7A7D2KGKNXAVCNFSM6AAAAABVAEGT2CVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKOBVGQ3DGOBWGQ> . You are receiving this because you commented.Message ID: ***@***.***>

[danyboy666]

You were right. CPU/PPU are all fine. I have two sets of them. I did have an issue with a ram chip but wasn't the ones I was using for the opentendo board. I did test the voltages and like you say I get 12v on two pins, 5v on the middle pin. Switches are set to internal vid/audio. I might have to swap tge power module for an original one just for testing. I really doubt it's one of the passive componants.

[ShawMerlin]

Are you using an actual CIC chip or one of the open source replacements? I have heard of some of the open source CIC solutions having issues with the rise of the buck converter which require a few different sizes of capacitors to fix. Let me know if that is the case for you and I can see if I can find that info on what to try. Thanks, -Merlin Shaw

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On Sunday, January 12, 2025, dferron ***@***.***> wrote: You were right. CPU/PPU are all fine. I have two sets of them. I did have an issue with a ram chip but wasn't the ones I was using for the opentendo board. I did test the voltages and like you say I get 12v on two pins, 5v on the middle pin. Switches are set to internal vid/audio. I might have to swap tge power module for an original one just for testing. I really doubt it's one of the passive componants. 20250112_094451.jpg (view on web) <https://github.com/user-attachments/assets/857dbc77-9c57-49ea-b260-5a3c6f7f903f> 20250112_094307.jpg (view on web) <https://github.com/user-attachments/assets/47483bf4-f9c3-4dd0-a39d-e4e541d11b83> 20250112_094318.jpg (view on web) <https://github.com/user-attachments/assets/205daab7-cfbb-4df8-ba0b-b9c10eeb8b11> 20250110_145717.jpg (view on web) <https://github.com/user-attachments/assets/a43c334b-2b6c-4222-b72a-e274c0c3b43b> 20250112_094307.jpg (view on web) <https://github.com/user-attachments/assets/bc562ab8-5598-473e-9fcf-c528159f0ed2> — Reply to this email directly, view it on GitHub <#21 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AQZJHHSQFPLTZ3G6CDIPBAT2KJ6PTAVCNFSM6AAAAABVAEGT2CVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKOBVG43DIMZZG4> . You are receiving this because you commented.Message ID: ***@***.***>

[danyboy666]

Yes it is the official cic which I confirm is working. I've also saw somewherenon reddit a user having luck with swapping C44 for something lower. Altough 220pf is the same value as on the original board. Also i've tried hooking up a chinese rgb mod board. I do get some garbbled characters and lots of static on screen using composite only. Will try to post some pics. I've used an original trimmer cap as well as the original nes oscillator. All does the same output on screen.

[ShawMerlin]

The YouTube channel “More fun making it” has a video of him using the RGBNES and one of these new power boards. He ended up having to change capacitor values too but i think that was more related to the RGBNES board. It might be helpful so I thought I would share. If you have access to a original power module, you could swap it in to take the power board out of the equation. Thanks, -Merlin Shaw

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On Sun, Jan 12, 2025 at 2:07 PM dferron ***@***.***> wrote: Yes it is the official cic which I confirm is working. I've also saw somewherenon reddit a user having luck with swapping C44 for something lower. Altough 220pf is the same value as on the original board. Also i've tried hooking up a chinese rgb mod board. I do get some garbbled characters and lots of static on screen using composite only. Will try to post some pics. I've used an original trimmer cap as well as the original nes oscillator. All does the same output on screen. — Reply to this email directly, view it on GitHub <#21 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AQZJHHRBTD7IIXJ42OFWDRD2KLKSTAVCNFSM6AAAAABVAEGT2CVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKOBVHEYTMOBSGA> . You are receiving this because you commented.Message ID: ***@***.***>

[danyboy666]

Yes I think that would be the logical step to try to rule out anything related to the power module at least. So close yet so far lol. I'll try this tomorrow I do have acces to a power module. I even have a second opentendo board pretty much ready to test. Thanks alot for this.

[danyboy666]

It only took three days of screwing around.... I should have tested with and original power module at first.

It's working even without the trimmer cap. Something is up with the power module I was sold I'm not sure what. I think i'll retest it just to be sure but it's almost certain it's that. Maybe a bad solder somewhere or even a bad (only) transistor. I did check it to be sure with a diode tester but in circuit so i'm not entirely sure it's right or not but i'm not reading the same values. I'm kinda glad it wasn't my opentendo build lol.

[danyboy666]

If I test with the new power module, problem is back.

[ShawMerlin]

The issue comes from a buck converter has a gradual rise to 5 volts while the original Power Module is a LDO so it's instant at 5 volts. This would be the same case for any switching buck converter providing the voltage to the main board. We have not ever seen this on the original main NES Board so there is something with how the timing circuit is working from the new main board. I have heard of others with OpenTendo's that had this issue with the new power module and they had to find the right capacitor in order to get it to work. Too low of a capacitor or none at all means that the timing hits too fast, too large of a capacitor means the timing hits too slow. From my notes, it looks like the last person that had issues used a 10uF capacitor to get his Opentendo to work with the new power module. If the original power module is working for you, there isn't a huge impact with using it compared to the new switching power module. Thanks, -Merlin Shaw

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On Mon, Jan 13, 2025 at 11:09 AM dferron ***@***.***> wrote: If I test with the new power module, problem is back.20250113_130703.jpg (view on web) <https://github.com/user-attachments/assets/b07de039-0b32-484a-ab08-2a8ab032e9d7> — Reply to this email directly, view it on GitHub <#21 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AQZJHHQUFIGXNSEARNLOOF32KP6L5AVCNFSM6AAAAABVAEGT2CVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKOBXHA2DONJWGE> . You are receiving this because you commented.Message ID: ***@***.***>

[danyboy666]

I do have some plans with those boards so idealy would be nice to have them work on opentendos since I have some main board pcbs already printed. Do you remember which capacitor? If it's the timing circuit my guess would be C44 like i've mentioned before? It would be certainly helpful to others if they have this issue too. At least it would be documented somewhere.

[ShawMerlin]

I believe it was the 10uF capacitor that he used. There is an active discussion on it right now with the Dubesihower's Modding group under NES-Help https://discord.gg/MUc7uMyH Zaxour is on that thread and has a lot of information on the timing circuit and these capacitors. I am sorry that I am not as much help as with analog things, timings are very critical for the reset circuit. I plan on documenting it on Github when there is more of a concrete answer. Lots of Opentendo's have worked without having to mess with the timing capacitor, only just a couple of shown this issue. Thanks for your patience on this, -Merlin Shaw

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On Mon, Jan 13, 2025 at 12:06 PM dferron ***@***.***> wrote: I do have some plans with those boards so idealy would be nice to have them work on opentendos since I have some main board pcbs already printed. Do you remember which capacitor? If it's the timing circuit my guess would be C44 like i've mentioned before? It would be certainly helpful to others if they have this issue too. At least it would be documented somewhere. — Reply to this email directly, view it on GitHub <#21 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AQZJHHTEUAYSKFH37JYCC7T2KQFCVAVCNFSM6AAAAABVAEGT2CVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKOBXHE3DSMJWGY> . You are receiving this because you commented.Message ID: ***@***.***>

[danyboy666]

There seems to be a mistake in the BOM for the power module.
Q1 is listed as 2SA1015 which is TRANS PNP ECB -150MA -50V SOT2 but the digikey link is https://www.digikey.com/en/products/detail/toshiba-semiconductor-and-storage/2SC2712-BL-LF/6691223 which is 2SC2712-BL,LF TRANS NPN 50V 0.15A S-MINI
this is for the basic RCA module, i did not validate if the other BOMs are like this.
2 completely different transistors