Jaguar CD Development Unit - Red Screen

[sheath]

I should have been more clear. While I had the CD opened up to swap the bios out I took out the connector board and cleaned the pins on both sides. They weren't dirty. But is this black screen issue indicative of the pins there having a bad connection.

 

I was also wondering if having a cart in the jaguar CD cart port was a good way to test if the unit was working before taking it apart further.

[SainT]

The developer CD unit doesn't contain any BIOS ROM, It needs to be loaded into an alpine board, or you should be able to flash it on the skunk otherwise you'll just get a red screen. The boot ROM is actually just mapped to the normal cart space, any additional hardware mapping (which is up at the top of cartridge ROM space) is decoded by the CD hardware itself, so that shouldn't be a problem.

 

So if you get a copy of the CD bios (https://www.google.co.uk/search?q=jaguar+cd+bios), modify it with makefastboot (https://github.com/tursilion/makefastboot) to be a 16bit ROM (on the JagCD its 8bit), then flash it, it SHOULD run. I've certainly booted my own assembled version of the CD BIOS this way via an emulator, of course it doesn't do anything without CD hardware support other than display a starfield / logo.

 

There are actually specific versions of the CD BIOS for developer units according to the Atari docs, so I'm unsure if you actually need one of these, or if the retail BIOS works.

Edited October 17, 2017 by SainT

[sheath]

I bought a bios from Console5. With it installed now, the bios no power screen comes up with the Jag CD Dev Unit plugged in or not, but now the cart port works! Previosly the CD unit wouldn't play carts at all and would only boot to a red screen.

Blue Lightning, my only game so far, doesn't spin up. If I release the tray lid button the screen goes black with interference on the video. As soon as I close the lid again the no power bios or cart boots again. So, at least I know the board works, not I get to figure out what the deal is with the power. I'm using a Jag AC adapter and a Genesis 1 AC Adapter, I've tested both with the base Jaguar and the Jag CD and there is no change. I guess the next step is to resolder that power jack on the Jag CD, or maybe I'll try cleaning all of the resetable power connections first.

[sheath]

With no leads on why the Jag CD would only display the no power bios screen with three different tested and working power adapters I'm stumped. With the power plugged in the laser visibly tracks, but only for the bottom 10% of the rail near the spindle, then the no power bios screen comes up. I ordered Philips Lens Optical Pickups VAM1202 Replace VAM1201 CDM12.1 CDM12.2 off ebay because I figure I'll end up needing to replace that too, but I don't see that solving the power issue. Is it possible I need to do something else to the Jaguar CD developer unit for it to boot to a cracked bios menu?

 

Any help would be appreciated. I'm not quite to the point of doing a full recap, and none of the capacitors are damaged. I also noticed that the connector board doesn't have any of the solder joints (resisters?) on it that I see on retail Jag CDs in online pics. This board just has straight through wiring to the Jaguar Cart port. But since cartridges now boot fine, I'm not thinking that connector board is part of the problem.

 

 

 

Edited November 5, 2017 by sheath

[neo_rg]

Is the old dev cable still attached?

[sheath]

Yes, it's soldered to the board right outside of the optical assembly.