Shift838 Posted June 26, 2015 Share Posted June 26, 2015 All, I have a mini-memory cartridge that is showing some odd behavior. It has had the external battery modification done to it and uses a CR2032. I purchased this MM module off ebay quite some time ago with the battery mod already done. I know I tested it when I got it and took the battery out after I tested it. Now after putting a new battery back in it and it seems that I do not have an issue when I type a small program and type 'SAVE MINIMEM'. No errors. But... But even if I do not power the console down and type 'NEW' and try the 'OLD MINIMEM' command I get the below error: * WARNING: CHECK PROGRAM IN MEMORY * I/O ERROR 57 anyone seen this before? Quote Link to comment Share on other sites More sharing options...
fabrice montupet Posted June 26, 2015 Share Posted June 26, 2015 (edited) Your Minimem has lost the program, it doesn't find it (ERROR 57)Many reasons can cause a such problem. Maybe both sides pictures (in good quality) of your Minimem could give an indication. Edited June 26, 2015 by fabrice montupet Quote Link to comment Share on other sites More sharing options...
+Schmitzi Posted June 26, 2015 Share Posted June 26, 2015 Hi, maybe, with a bit luck, the new battery just is empty, or you just have problems on the contacts of the battery-holder ? 1 Quote Link to comment Share on other sites More sharing options...
Shift838 Posted June 27, 2015 Author Share Posted June 27, 2015 (edited) i have tested the contact on the battery holder and all are good as well as the battery is putting out 3.19 volts What should the power voltage be through the circuit on the RAM chip? Edited June 27, 2015 by Cschneider Quote Link to comment Share on other sites More sharing options...
Shift838 Posted June 27, 2015 Author Share Posted June 27, 2015 (edited) I checked my voltage on the ram chip and I am getting around 2.12v and I believe that is enough to retain the program in memory. The only thing I can think of is that it's not actually saving my program to the mini memory cartridge at all and that is what is causing the actual error when I try to issue the 'OLD MINIMEM' command. As I think if it was saving it I should be able to issue the new command then the OLD MINIMEM and it would pull it. So I am wondering if I have a more extensive issue with the cart. Edited June 27, 2015 by Cschneider Quote Link to comment Share on other sites More sharing options...
+Schmitzi Posted June 27, 2015 Share Posted June 27, 2015 Yes, it sounds like "bigger" problems... ( and sorry, I did not see that you wrote that the error also occurs without powering down, so, there should be a somehow bigger problem, of course ) Quote Link to comment Share on other sites More sharing options...
fabrice montupet Posted June 27, 2015 Share Posted June 27, 2015 No pictures? Sometimes, they are very useful to find the problem.Are the 4148 diodes and 3906 PNP transistor OK? You can also test the 1K and the two 3.3K resistors.The 3904 NPN and 5.1K resistors are OK because your cartridge works when it is powered from the TI-99 1 Quote Link to comment Share on other sites More sharing options...
Shift838 Posted June 27, 2015 Author Share Posted June 27, 2015 Front and back pictures of module.. Quote Link to comment Share on other sites More sharing options...
+Ksarul Posted June 27, 2015 Share Posted June 27, 2015 I see two things that aren't right--one is that the memory chip at the bottom of the stack has been replaced (potential soldering issue or a bad chip), the other is that the 6116 on the top of the stack is just sitting there--it doesn't look like it is soldered at all, which would indicate someone was trying to resolve a memory issue by piggybacking chips. . .leading us back to problem number one. Quote Link to comment Share on other sites More sharing options...
fabrice montupet Posted June 27, 2015 Share Posted June 27, 2015 Thank you for the pictures, they are instructives. Yes, the solderings of the top SRAM 6116 seem to be absent ! It is impressive, awful...But it doesn't fully explains your problem because, by your tests, it seems to be possible to store a program into the Mini-Memory (but a little program in all case! because of the bad solderings on the top SRAM...). Your problem seems to be the incapacity for your cartridge to maintain power supplied by the 3V lithium battery. It is the reason why I think about a diode/transistor/resistor issue, the ones connected to the battery. May be a bad connexion of the SRAM pins caused a short-circuit and the destruction of one of these components. Can you tell me what your multimeter say? Quote Link to comment Share on other sites More sharing options...
Shift838 Posted June 27, 2015 Author Share Posted June 27, 2015 (edited) I see two things that aren't right--one is that the memory chip at the bottom of the stack has been replaced (potential soldering issue or a bad chip), the other is that the 6116 on the top of the stack is just sitting there--it doesn't look like it is soldered at all, which would indicate someone was trying to resolve a memory issue by piggybacking chips. . .leading us back to problem number one. I guess my pictures were not good enough. The top RAM chip is soldered. Of course I do not know who worked on it originally so you are probably right there are probably issues when the soldering. I guess I could purchase new chips and redo them. I did notice that the 6116 RAM chip has pin # 18 snipped off and a solid wire soldered to it and down to the PCB hole between the two resistors. I do not know if this is normal as I have never worked on a mini-memory cartridge or opened one until now. As well as it looks like on the chip around that pin is burnt (thanks to the HIRES photo!).. Maybe I should replace both chips? What is the chip underneath the 6116? Edited June 27, 2015 by Cschneider Quote Link to comment Share on other sites More sharing options...
fabrice montupet Posted June 27, 2015 Share Posted June 27, 2015 (edited) Did you test the components that I told to you? Pin #18 of a SRAM 6116 is the Chip Select. So, it is normal that the pins #18 of the two SRAM are not soldered together. On the Mini-Memory, the pin #18 of the top SRAM is soldered to the hole just near the hole where the bottom pin #18 SRAM is soldered, thanks to a flying wire. EDIT: It's a good news that the top 6116 SRAM is well soldered! :-) The picture was misleading. Edited June 27, 2015 by fabrice montupet Quote Link to comment Share on other sites More sharing options...
+OLD CS1 Posted June 27, 2015 Share Posted June 27, 2015 Two 2k RAM chips stacked, that pin is the "bank" select between the 2k for a total of 4k RAM at >7000. But it looks like there has been some shoddy solder work in these here parts. Quote Link to comment Share on other sites More sharing options...
fabrice montupet Posted June 27, 2015 Share Posted June 27, 2015 I also asked myself if the soldering on #18 pin top 6116 was good, the picture is so blur that it's difficult to pronounce with certitude. Quote Link to comment Share on other sites More sharing options...
Shift838 Posted June 28, 2015 Author Share Posted June 28, 2015 i think i may have found an issue with the soldering of the ram chips. it appears the bottom ram chip pin #12 is not connected to the board. I believe that is the ground correct ? Quote Link to comment Share on other sites More sharing options...
Shift838 Posted June 28, 2015 Author Share Posted June 28, 2015 Your Minimem has lost the program, it doesn't find it (ERROR 57) Many reasons can cause a such problem. Maybe both sides pictures (in good quality) of your Minimem could give an indication. Fabrice, Thanks for suggesting the HIRES pictures! It helped me looking more and more and that's where I found that the ground pin was broken off of the bottom RAM chip. Soldered a jumper wire and BAM. All working. Thanks guys for all your suggestions! sometimes you just need more eyes than yours! 1 Quote Link to comment Share on other sites More sharing options...
Opry99er Posted June 28, 2015 Share Posted June 28, 2015 Grats!! Quote Link to comment Share on other sites More sharing options...
Dexter Posted June 28, 2015 Share Posted June 28, 2015 I recently could borrow both manuals from a nice guy here on the forum! I scanned both manuals in high quality. If there's any interest? 1 Quote Link to comment Share on other sites More sharing options...
Shift838 Posted June 28, 2015 Author Share Posted June 28, 2015 I recently could borrow both manuals from a nice guy here on the forum! I scanned both manuals in high quality. If there's any interest? definitely interested.. Quote Link to comment Share on other sites More sharing options...
Dexter Posted June 28, 2015 Share Posted June 28, 2015 (edited) definitely interested.. I'll post it in a few minutes... edit: here is the link: http://atariage.com/forums/topic/239861-mini-memory-lbla-manuals/ Edited June 28, 2015 by Dexter 1 Quote Link to comment Share on other sites More sharing options...
fabrice montupet Posted June 29, 2015 Share Posted June 29, 2015 Fabrice, Thanks for suggesting the HIRES pictures! It helped me looking more and more and that's where I found that the ground pin was broken off of the bottom RAM chip. Soldered a jumper wire and BAM. All working. Thanks guys for all your suggestions! sometimes you just need more eyes than yours! I am very happy for you! :-) Quote Link to comment Share on other sites More sharing options...
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