IFU Backup Memory corrupted?

[elartur77]

I got this PC Engine/CDROM2/IFU combo, but the memory backup in the IFU seem to be corrupted, the images are from the memory manager, all the texts has this lines over, when I try to format it does nothing.

HuCard games works great but games that uses the Backup memory cant save, doesnt detect it, the CDRom games doesnt work at all, the disk dont spin at all and after a little while just got "please set disk".

I know the PC Engine and CDROM2 works fine because they work flawlessly on another IFU I have.

I try with a TenoKoe Bank but it says that doesn't find any memory backup at all!

Then I use the BRAM TOOL and all I got was this "BRAM IS NOT PRESENT", so I replaced the supercapacitor but still the same. Its possible that the BRAM chip got corrupted?

I dont know if doing the FRAM mod will solve my problem, I dont want to mess with it because I think is way over my soldering skills.

So does someone had an idea whats wrong with it and how to solve it?

Thanks!

[Keith Courage]

That's probably bad ram. Not the actual save ram. This is the ram that's used to load data into in order for games to run. This is why none of your CD games will boot.

If the problem was just the actual save memory, then games would still load and run fine. You just wouldn't be able to save anything successfully.

There are two identical ram chips on the small removal board. One of the two chips is probably bad. Unfortunately, depending on the chips that are in there, some of these can only be sourced from other ifu docking stations.

So depending on the cost for buying another already working correctly docking station, it might make it pointless cost wise to buy another one to use for parts.

There are different revisions of the ifu docking station. So not all of them have the exact same upper board and same RAM chips on it. Meaning, not all of them are interchangeable.

This problem is most definitely not bad capacitors. So it would be a waste of time and money to change the capacitors out thinking it would fix the problem.

[elartur77]

Thank you very much for your reply!

This info helps a lot, it makes sense your explanation about the ram, so its not worth it to repair this unit, they are not that expensive either so better get another one.

If I could get those ram chips at a reasonable price maybe could be viable for repair.

Anyway, thank you very much again.

[Tak-MK]

It's already answered, but I wanted to add too that in my experience that's because of a VRAM IC, at least everytime I get that in any other console it's 99% related to some VRAM failing, but sadly I never changed one in an IFU.
Good luck!

[elartur77]

Hello.. bumping an old thread, its me again...

Its has been a while, after trying to repair I follow the recomendation from Keith Courage and got another IFU because they are pretty cheap, but now I wanted to give it another go, so here is what I just did with the unit..

I changed booth RAM chips with a SONY CXK58257M  I used this model because when I remove the original M5M5256BFP-70 (Mitsubishi) chip, under it there was a text in the board SONY CXK58257M but still got the same lines and "no BRAM present" message from the BRAM TOOL, so I think this isnt a RAM issue, next I replace capacitors on the board and same thing happened, and at last I try to do the FRAM mod and still the same thing..

Now Im lost, I dont know if the culprit are the other 3 chips left HC245 (74HC245 Texas Instruments) that are around in the RAM board.

So anyone can give me a little help..

Its not like I need to repair this, I alredy have the other IFU working great, this is like a little project to test my skills and if I could make it work in the process, that would be great..

Thanks..

[NightWolve]

Oh wow!

Before Chris/Keith sees this and maybe can offer advice, how about Covell himself who made that BRAM tool ? You can also ask him on X/Twitter: x.com/covell_chris

[Keith Courage]

Wait a minute! I just went back and read your first post about this. Does the CD drive still do nothing when you hit the run button?  Does the CD drive power on if you hit the play button on top of the CD drive? If the Drive doesn't power on either way, then you are missing power from one area of the board for some reason. There should be 9V-10V getting to the CD drive IO connector when you turn on the switch to lock the IFU and have the PCE powered on.

I'm trying to remember what I did to repair this in a DUO before. I'm pretty sure it was a bad trace. For most IFUs, I've just swapped that entire top board out as I used to have a bunch of IFUs  on hand with various problems. I could swap enough parts around to make more usable IFUs.

Usually the symptoms of bad Ram for the CD drive is glitchy graphics for when CD games load or a Black screen once a CD game loads. So your Ram may have been good and this could be my mistake for not noticing your CD drive was not powering on. I was just paying attention to the lines shown on your CD bios save manager screen. Sorry for not noticing that part.

[elartur77]

Hello Keith. Thanks for your reply..

I just check it out and my CD unit is getting power, when I press run button at the bios screen the red PC text turns on, and when I press play just connected to the IFU it appears the track is trying to play, so Im getting power.

Then I check the small PCB and I saw some broken traces (2), they werent visible because the yellow residue of the original flux, but after cleaning they are very evident, but this doesnt seems to be an "accident" it seem to be on purpose because those traces goes to other lines with wires with that gunk to keep them in place, so it seems like they fixed the board with that..

I dont know if I try to connect those traces will fix my problem, maybe I should try, but after checking continuity those traces seems to connect with each other , maybe Im going to short them..

So any other Ideas?

[Keith Courage]

Those traces are definitely cut on purpose from the factory. So I wouldn't connect them.  I'm lost on what to check next. We need The Steve to comment on this one because I can't remember what trace I repaired to get this working in a DUO before. I'm pretty sure it was a bad trace from the save memory to the larger D91317GD chip, but I can't remember for sure.

[elartur77]

Thanks Keith, I hope The Steve could give some help over this  , in the meantime Im going to check that board again for bad traces.

Thanks again..

[thesteve]

Could actually be bad ram
I have run into that before
Obviously check traces
Logic probe is your friend, floating lines don't work

[thesteve]

The lines are evenly spaced, likely a stuck data bit
Test CD player (music)
Should be informative

[thesteve]

This differs from a DUO in one very significant way (and several smaller ones)
The DUO maps the CD system ram and ROM, where that is handled by the CD system card in this case
The duo uses 1 SMD ram chip for data buffer where the IFU uses 2 DIP package chips to do the same
The sample ram is the same on both

[elartur77]

Hello Thesteve, thank you very much for your reply..

This weekend Im going to check all traces and use my logic probe that should be somewhere in home..

I has been busy with work and other projects  but I really want to fix this, Ill update with the results...

Thanks..