Recent content by Big_P Big_p

Interested in your progress. Can't help much I sold my last CPS1 a few months back.

Like I said Max Amp draw pf a RPI4B is only 1.52A you will be fine. I have looked up the specs and metered it with netboot running the max I could get it to pull was just under 1A (954mA)

Is there any reason you need more than 3.5A for a RPI4B? That should be plenty unless you are running so power hungry hats. At idle the 4B draws 0.51A (2.5W) under load maximum draw is 1.52A or 7.6W at 5V. The CN12 connector (or is it CN2 I forget) draws off the 5v rail so it should be fine. I...

Buy this one, doing it yourself will cost you twice as much. Love the stickers.

At a quick look you seem to be right. I'll fully check it out when I get a chance but it definitely looks promising.

Is Is it a straight swap? I have looked previously and don't remember finding anything that would work without additional modifications, but if it does its a good idea.

@GC8TECH are you saying that in your experience that is normal battery consumption? What about a 1f 5v supercap battery replacement? I have looked at this a little for the MVS but have not gotten around to looking at the charging circuit to see if it's off the 5v or 12v line and if overcharging...

Can you meter the voltage drop in the battery between when the PGM is first switched off and at 15min, 30min and 1hr. It does indeed sound like a parasitic drain and there are a few things that it could be.

I also made up a pcb to tap the 5v connector on the Naomi and provide a usb c out to the pi. Just in the process of adding a second usb c port to potentially power an I/O too. I should have this done soonish as well.

I have repaired a few Naomi's for people, I have about 12 Naomi's in various states of working and I have a fair collection of "not tested" netdimms and dimms but have never been able to get a Naomi set up working. The motivation to keep trying came from CVS2 and someone who sometimes frequents...

Anyone tested these with other eeproms 27c322 should almost be possible as well.

Yeah all of @Ziggy Cheetos Dust restorations are amazing. Inspired the Chandy and seriously thinking about giving the ziggy treatment to an exceleena project cab. Makes you proud to see what your fellow country people can do when they give it a go.

C3 0.1uf 0806 cap goes and causes a drain. Also check C10 (it could be PC3 and PC10) - 0.1uf 0602 cap U3 - 74HC32 SOP8 if pins 12 and 13 have a voltage it tries to power the MVS off the battery (I doubt it's this because your drain takes a few days) RAM2/RAM4 - 256kx8 sram SOIC28 (i have...

Is it an MV1c? These are notoriously bad for draining batteries. A few things can go to cause this but C3 (0.1uf) is often the cause.

Can you check if you have any reverse voltage at the holder when on. I don't on mine but once it's in the MVS its a little hard to check others. The other issue could be that you have a high draw on the battery when off this is typically one of the smd passives in the bios circuit. Let me know...