A500+ doesn't start with A590

[IlyaZ]

The A500+ starts independently, but when I connect the A590 HDD the A500+ green light doesn't turn on. The HD spins up and gets power. Switch is on 1 which is autoboot. I should add that the original A590 PSU did not provide power, so I went ahead with what I suspect is a vintage internal PSU I found lying around that had the same connector modded onto it, which at least gave power to the unit.

[F0LLETT]

The A500+ starts independently, but when I connect the A590 HDD the A500+ green light doesn't turn on. The HD spins up and gets power. Switch is on 1 which is autoboot. I should add that the original A590 PSU did not provide power, so I went ahead with what I suspect is a vintage internal PSU I found lying around that had the same connector modded onto it, which at least gave power to the unit.

You sure its an a590? as they dont have switches. GVP HD+ does.

[IlyaZ]

It says Hard Drive Plus A590. "Switch" on the back 1 through 4. 1 is in the up position.

[Vanders]

The A500+ starts independently, but when I connect the A590 HDD the A500+ green light doesn't turn on.

Do you mean the power light on the A500+ doesn't turn on? That sounds like the A590 might have short on 5V (the HDD will spin up from 12V)

You sure its an a590? as they dont have switches. GVP HD+ does.

The A590 definitely has a set of 4 DIP switches at the back.

[IlyaZ]

Yes, power light doesn't turn on. PSU 5V output at fault? I'll check with a multimeter. If not, could a short occur on the A590-side? Capacitor that turns short instead of open?

[Vanders]

Yes, power light doesn't turn on. PSU 5V output at fault?

If the power light on the A590 is on then no, that PSU is probably fine.

If not, could a short occur on the A590-side? Capacitor that turns short instead of open?

Possibly, yes. It's going to be a tricky one to diagnose if the A500 doesn't power on at all. You can also try plugging the A590 in with the top cover & shield removed, turn on the power to the A590 & A500, and check to see if any of the chips are getting hot.

[F0LLETT]

The A590 definitely has a set of 4 DIP switches at the back.

Well I never, learn something new every day. Had one for around 3 years and never even knew it coud add fast ram.
Spose when your a kid, things like that dont interest you. Aslong as you can fill your massive 20MB HDD with games, .

Yes, power light doesn't turn on. PSU 5V output at fault? I'll check with a multimeter. If not, could a short occur on the A590-side? Capacitor that turns short instead of open?

Might sound silly, you cleaned edge connector? I have seen some wierd and crazy issues with dirty edge connector.

[IlyaZ]

Edge connectors seem clean, also cross tested with another A500+ with the same result.

Why do bad chips turn hot, just end up getting higher resistance?

[arttu80]

You can also check if there is "power supply mod" present under the A590 PCB. I made this mod years ago to use only A500 own supply (must be something more powetful than stock A500 unit) without additional supply for A590.

https://www.youtube.com/watch?v=YIVN31HTtCk

[kolla]

end up getting higher resistance?

Rather the opposite, less resistance and more current going through, causing heat.
Not to mention, current going where it shouldn't.

[scuzzb494]

I have several A590 units and unless you set the DIP switches correctly the sidecar won't boot.

Only DIP switch number 1 should be in the up position and on.

Switch 01: Is for selecting the boot WB required after WB1.3
Switch 02: Selects external drive unit numbers so if nothing plugged into the SCSI it should be off.
Switch 03: Is a delay for drives that require such a thing. So switch can be off.
Switch 04: Is reserved for future use and should be off.

https://www.scuzzscink.com/amiga/scuzzblog_november24_1/car_sbd_061124_04.jpg

Now I have several of these units and I actually have  one that appears to be wired incorrectly. Only when I set switch 1 to OFF and the rest to ON would it work. And that is when I discovered that if the swiches are not correct the unit will not boot.

Not sure you have the manual.

https://www.scuzzscink.com/amiga/car_libs_012.htm

[giZmo350]

Go Scuzz!  Good to see your still around! 

[bp500]

I should add that the original A590 PSU did not provide power, so I went ahead with what I suspect is a vintage internal PSU I found lying around that had the same connector modded onto it, which at least gave power to the unit.

To my knowledge the original A590 PSU is wired in such a way that will provide power to the A590 only when the connected Amiga 500/500+ will be turned on.
The Amiga 500/500+ wont boot if an A590 is connected and not properly powered.

Are you 100% certain that your original A590 PSU doesn't work?

I would suggest to try again using your original A590 PSU (and of course turn it on before powering your A500+)