Odd Issue with 130XE with Fujinet plugged in

[Jfcatari]

I have two 130XE's both using the same power supply.

 

When I plug the fujinet (no external power plugged in) into the one the config screen is more on the GREEN side than BLUE.  The other 130XE with the exact same setup is BLUE.

On the one that is on the GREEN side, it turns more BLUE when I add the external power supply to the Fujinet.

 

Any thoughts one where to focus on the 'GREEN' one?

 

 

 

[+x=usr(1536)]

18 hours ago, Jfcatari said:

I have two 130XE's both using the same power supply.

 

When I plug the fujinet (no external power plugged in) into the one the config screen is more on the GREEN side than BLUE.  The other 130XE with the exact same setup is BLUE.

On the one that is on the GREEN side, it turns more BLUE when I add the external power supply to the Fujinet.

 

Any thoughts one where to focus on the 'GREEN' one?

Power supply and / or voltage regulator.  It sounds like the FujiNet (or something else) is drawing down the XE's power to the point where the GTIA is being weird when it's connected.

 

FWIW, I did catch that you're using the same PSU with both machines.  To eliminate the PSU as a possibility, you'd need a second known-good one to test with.  Having said that, it seems more likely that the VR (as a starting point) may be getting flaky.

 

Also, check voltages on the main ICs (not just the GTIA) with the FujiNet both connected and removed.  If they're under 5VDC at any point, at least you know it's a power issue.

 

Is this FujiNet one that was handbuilt or did you buy it from a retailer?

[Jfcatari]

7 minutes ago, x=usr(1536) said:

Power supply and / or voltage regulator.  It sounds like the FujiNet (or something else) is drawing down the XE's power to the point where the GTIA is being weird when it's connected.

 

FWIW, I did catch that you're using the same PSU with both machines.  To eliminate the PSU as a possibility, you'd need a second known-good one to test with.  Having said that, it seems more likely that the VR (as a starting point) may be getting flaky.

 

Also, check voltages on the main ICs (not just the GTIA) with the FujiNet both connected and removed.  If they're under 5VDC at any point, at least you know it's a power issue.

 

Is this FujiNet one that was handbuilt or did you buy it from a retailer?

This is my hand-built devkit version.

In my tests with each 130xe everything was the same. Nothing is getting hot on the green one.

I will check voltages at the gita especially.  The green 130xe is a recent buy from ebay.

 

Got a source for 130xe regulator?

Edited September 13, 2023 by Jfcatari

[+x=usr(1536)]

2 hours ago, Jfcatari said:

This is my hand-built devkit version.

In my tests with each 130xe everything was the same. Nothing is getting hot on the green one.

What tests have been conducted so far?

 

It's possible for there to be problems without anything getting hot, FWIW.

2 hours ago, Jfcatari said:

I will check voltages at the gita especially.  The green 130xe is a recent buy from ebay.

 

Got a source for 130xe regulator?

Sorry, minor brain fart on my behalf: the regulators on XLs and XEs are in the PSU.  Apologies for giving the impression they're on the motherboard.

 

You may want to try a USB adapter rated for at least 2A.  See https://www.8bitclassics.com/product/atari-xl-xe-usb-power-cable/ for the appropriate cable.

[Jfcatari]

2 hours ago, x=usr(1536) said:

What tests have been conducted so far?

 

It's possible for there to be problems without anything getting hot, FWIW.

Sorry, minor brain fart on my behalf: the regulators on XLs and XEs are in the PSU.  Apologies for giving the impression they're on the motherboard.

 

You may want to try a USB adapter rated for at least 2A.  See https://www.8bitclassics.com/product/atari-xl-xe-usb-power-cable/ for the appropriate cable.

 

Thanks for all of the pointers!

 

False alarm on the 130XE greenish screen.   I had a marginal PSU being used.  I should have started their first.  I guess one of the 130Xe's was OK with the lower input value.

 

With a good PSU that is outputing 5.12v both 130XE's are A OK with blue colors on the Fujinet config screen when the Devkit Fujinet is pulled in WITH or WITHOUT power to the Fujinet!