Is NanoPEB touchy about supply voltage?

[Kchula-Rrit]

Another one of my pesky questions--

 

My NanoPEB lately seems a bit "iffy," giving "DSR error 6" upon loading the second file of large programs like CF2K, or just locking up.  My thoughts are:

 

1. The NanoPEB is touchy about its supply voltage.  My set-up has the console and NanoPEB running from the same supply, a battery supplied DC-DC converter.  There was lots of power-line noise before I added filters.  The voltage at the "navel" power connector is 4.84V.  Haven't checked noise levels.
2. The EPROM in the NanoPEB is losing its data.  I remember, in the 1980s, hearing of EPROMs being erased by sunlight from friends who had their home-made systems near outside windows.  My system sits near a window and I wonder if the label on the EPROM is letting some UV from outside to get in, which could slowly erase the DSR.
3. I need to beef-up the power wiring from the supply to the console/NanoPEB.  I originally used 22 gauge wire in the power supply; the charts I read said it should handle three amps, which I figured was enough for the system.  The supply-to-console power cable is doubled-up because it is about three feet long.
4. The NanoPEB edge connector is touchy.  After I re-seated the NanoPEB I was able to run CF2K without failure, but I'm not sure I trust it.  I've had to re-seat the edge connector before.  I wonder if I replaced the edge connector with something like the header connectors on IDE drives, or that Arduinos use, if it might not be more "stable" for the long term.

 

Ideas?

 

K-R.

 

[+Schmitzi]

From "100 issues" I had with my Nanos 80 where about bad power, 10 about defective card readers

and the rest about loose chips/contacts or bad soldering points...

I would never power it from the console or any dirty tricks

I only use the "finest", regulated power suplies, with much Amperes (~1.5-2A)

 

Which Nano/Version do you have ?

 

[+arcadeshopper]

From the mfgr of the nano/cf7:
Only use a regulated 5v power supply

I sell appropriate supplies in my store

Sent from my LM-V600 using Tapatalk

[Kchula-Rrit]

Sounds like the Nano is rather touchy about power, given Schmitzi's experiences.  I suppose it doesn't help the CF board contacts that I have to remove the CF to plug it in to my PC to transfer files.

 

After I adapted my console to run on batteries (see the BATcomputer article in the main forum) I put the Nano's brick "away", which means I cannot locate it.  I found one from a dead router, +5V, 2.5A, to power the Nano, and it worked okay.  The +5V supply noise at the Nano's power plug was about 100mV p-p using the brick, similar to the noise when I used the battery supply I had built.

 

While I'm beefing-up the power cable I'll add a 470uF cap to add some more filtering.  My original battery set-up assumed that the console has lots of filter/bypass caps.  I know about "assume", and I took a short cut...

 

At the title screen it says NANOPEB-SIO V1, and the label on the EPROM says V.1.

 

Thanks,

 

K-R.

 

 

[+Ksarul]

I have some really robust 44-pin Sullins connectors I bought from Digi-Key, both in side-saddle and WW style. The relatively cheap Chinese connectors on the Nano are what you pay for--low quality and quickly worn out. Some don't even use true 44-pin connectors--the builder cut down some larger pin count connectors to get a shade-tree 44-pin connector.

[Kchula-Rrit]

My Nano's edge connector appears to have some shave/sanding marks that would indicate it was cut down from a larger one.  I think ISA (PC/AT style) boards had two connectors.

 

I just wonder about the reliability of the forty-year-old edge connectors on our consoles.

 

I was toying with the idea of soldering a wire-wrap pin-header to the console edge connector to make a more secure connection, like on IDE disk drives and some floppy disk drives.  Don't want to do anything irreversible, though.

 

K-R.

 

[+Ksarul]

Actually, the edge connectors TI used were seriously robust. The only issues I've ever seen with them was when someone succeeded in bending one of the leaf spring contacts to short out against another pin. I usually just bend them back and all is good, but when I find a really bad one, I replace it with a new saddle-style connector. I bought a goodly number of those as the minimum order numbers are definitely too high for one-off projects--but OK for some of the things I've been doing, so I just buy plenty of extras to allow me to have enough to be able to help out when someone is just looking for one.

[Kchula-Rrit]

Ksarul, what's a saddle connector?  I cannot say I've heard of one.

 

Sounds like you were talking about the female side, like on the Nano or the fire hose.  I was talking about the contacts on the console edge connector being worn down from being plugged and unplugged.  After all, they are just very wide/thick traces on the motherboard.

 

K-R.

 

Edited April 1, 2021 by Kchula-Rrit

[+Ksarul]

On 4/1/2021 at 2:51 AM, Kchula-Rrit said:

Ksarul, what's a saddle connector?  I cannot say I've heard of one.

 

Sounds like you were talking about the female side, like on the Nano or the fire hose.  I was talking about the contacts on the console edge connector being worn down from being plugged and unplugged.  After all, they are just very wide/thick traces on the motherboard.

 

K-R.

 

Look at the 44-pin connector in the speech synthesizer. That is a saddle-style connector. The long pins are formed to grip the front and the back of the board (and the Sullins connectors I use are new-manufactured, not leftovers from 20 years ago sold as NOS). I have quantities of the same connectors with straight wire-wrap post-type pins (they are otherwise identical to the saddle connectors, without the necessary pin forming to grip a circuit card).