cfarl

Here is the datasheet for LM323: https://www.onsemi.com/pdf/datasheet/lm323-d.pdf You can find it at Ali Express.

Just reporting... I have lost my TIA and processor because of the related problem. Then, I replaced 7805 by LM323, wich is like the "7805" regulator, but supporting 3A of output, instead of 1A. Now I can find 5v in the output of the LM323, and the problem above reported is gone. Hope this information can the useful for someone else.

Hi, guys! I've been using Pluscart Duo for some time from now, but I had some problem with my Atari, and I want to share it with you. I have a Etim rgb mod in my Atari, and sometimes I observed that Pluscart stopped to work and presented me a solid screen after some time of use (after some minutes). One time I insisted on keep it powered on, and I have my TIA damaged.... So, I got a new TIA, replaced it, but I have observed that the problem was happening again. Then, I started to find what was happening. Using only the Atari as it was made (with a normal cartridge Freeway and without using the rgb board), I found it was draining something like 0.29mA from the power source, and the output of the 7805 regulator was something about 4.9v. Using Pluscart I found something like 0.39mA, and the output of 7805 dropped to 4.8v. But look at this.... When using Pluscart and the Etim rgb board at the same time, I found 0.5mA, and the output of 7805 dropped to 4.6v, after some time. I found the 7805 was getting hotter, and as more hot it was, more its output was dropping... Until the time Pluscart stopped working and presents a solid screen to me, as before. I tried another 7805, with the same results. So, I found that this set (Pluscart + Etim rgb) is requiring a lot from 7805 (the Atari, as it was made, uses 0.29mA, and I was using two times this value), and it can even damage your console. Yes, it happened to me! Did someone else had a similar problem? Do you have a solution for this problem? I was thinking try to use a usb-c mod and use a 5v - 2A mobile phone power source.

Nice work, Al_Nafuur!!! I was wondering about something here.... Could it be possible to add the save/load state in future releases of PlusCart?

Nice! You can view it online here: https://www.altium.com/viewer/ Thanks!!!!

Thanks! From where did you get this diagram? Can you share it with us, too?

Nice! Can you provide us a image of your working board? I had a mounted Pluscart with no sd card recognized, and to replace the sd module I have to dessolder the board from the pcb.... And it's very painfull have to do this. It would be nice have another way to solder and remove the sd module.

Very nice case!!! Did you print it using some print service? Where is located the sd card in it?

Wow, have you seen the price of the STM32F407VGT6? https://www.aliexpress.com/item/32855505972.html?spm=a2g0s.8937460.0.0.65eb2e0eiqr9oi So, I was wondering.... Is this the only Board that could be used to build a Pluscart Duo?

Nice question, Andrew! First, I soldered it to build a Pluscart cartridge pcb. But then (I don't remember why, if it was because of the not working sd or wifi), I removed it (dessoldered it) from the cartridge pcb. So, in this process, I must be damaged some tracks....

I managed to get my other no-working STM to work. I have found two pins with broken tracks, and remade it: Now it is working as expected! Thanks for your help!!!

I'm thinking buying some oscillator tester, as this one, just to know about this. https://pt.aliexpress.com/item/32902587660.html?spm=a2g0o.productlist.0.0.70a433c10DOZgG&algo_pvid=51dbe012-a4cd-4597-919a-fe2b2da2593e&algo_exp_id=51dbe012-a4cd-4597-919a-fe2b2da2593e-5&pdp_ext_f={"sku_id"%3A"65817865303"}&pdp_pi=-1%3B46.85%3B-1%3B-1%40salePrice%3BBRL%3Bsearch-mainSearch

Ok, I removed the oscillator from the not working board and placed it in the working one.... And the working one is still working. Conclusion: the problem is not in the oscillator. I measured both the oscillators out of the circuit, the resistance is very high. Interesting thing, now the working board is measuring the high resistance even in the circuit. I could have done some mistake in my previous measure....

Well, now I'm working to bring the not working MCU back to life. I was checking all the componentes of the board, and discovered something interesting... In a working board, this component (the oscilator crystal) has very low resistance. But in my not working board, the resistance is very hight... Something like Mega Ohms. My conclusion: this component is not working. Now the problem.... I can't find the specification of this component in its body. Someone can help me on this? I want to replace this component, but I don't know what is it....

Good news! I have washed my not working cartridge with water and neutral detergent, and after this I have dryed it using a cold air hair dryer. Then, I remade the soldering of the MCU, used a microscope to check the terminals, and used a multimeter do check the continuity. Then, I tested it in my old Atari and.... It worked! Nice!!!!! I did the same with the other board, and tested in my test cartridge. But this one is still not working.... Well, at least one of them is working again! Thanks by your advice!