Bumping this, if there are any Amiga veterans or electronics-savvy people here that can help...

Specifically, if the pass-through should work directly at power on, regardless of drivers etc, and assuming the cable is ok: could a black screen indicate a fault local to some output circuitry selecting signal from card or pass-through? I mean, if there was something wrong with the cards own VGA circuitry, would that necessarily block the pass-through signal also?

I know too little about electronics to decide if I just should give up on the card or try to replace some components on it.

Here is a link to a hires image of a similar card
http://www.bigbookofamigahardware.com/bboah/m … ect24_f_big.jpg

The DB9 pass-through-input is the connector closest to the bottom on the right edge of the photo.

Which video signal have you connected to the passthrough port on the Spectrum? It usually takes the 15Khz RGB signal from the Amiga video port, I'm not sure that the 31Khz signal from the Indy ECS will work connected to the passthrough port. If it's possible, connect a vga monitor to the Spectrum and a second VGA monitor to the Indy ECS. If it boots into Workbench on the Indy ECS monitor, you'll be able to run any utilities that came with the Spectrum install disk and test the Spectrum card.

Perhaps the Indy ECS is interfering with the Spectrum (very unlikely) but it's worth a shot. Perhaps remove the Indy ECS and use a 15Khz monitor on the Amiga video port whilst still having the VGA monitor connected to the Spectrun and try running the Spectrum utilities again. From what I've seen in your specs, you're only running 4MB of Zorro 2 memory space, so it should be 100% fine. Maybe just check the memory jumpers on your GVP HC+8 card and make sure it's set for 2MB. If the jumpers are set for 8MB, the A2000 might see the Zorro 2 memory space as full and not initialise the Spectrum card.

You should be able to connect the Indivision's output into the passthru port without a problem. The Spectrum doesn't have any onboard scan doubler, just a SVGA chipset. Remember, folks with an Amiga 3000 were using these cards and that machine has an onboard scan doubler.

It should pass through with no problem without any software loaded. That is the point of the pass-through. I used one on my A3000 for years, I know it works with 31.5khz video just fine. I guess if the Indivision outputs something it doesn't like, it could interfere?

It is definitely getting some signal through the passthru. If I am connecting the monitor directly to the Spectrum and nothing to the passthru the monitor never wakes up, but with Indivision connected the monitor turns on. Still black though.

I'm sure it worked with Indivision before. IIRC I also tried a EGS resolution like 800x600 so the card seemed to work ok then.

If the Spectrum just lets through what it gets, and it is getting something, then the first suspect maybe should be the cable after all.
It may have some unreliable joints, since it wasn't super easy for me to solder it.

On the other hand I didn't have success with two separate monitors either. The GVP monitor stayed black after reconfiguring and rebooting, and all EGS software started up on the Indivision screen. But that could just be some configuration error or me not knowing how to use the software.

To be able to exclude the passthru cable as the error, I just ordered this one: http://www.ebay.com/itm/140933847221?_trksid= … K%3AMEBIDX%3AIT
Do you know if the Spectrum follows a standard mapping from HD15 to DB9 so this would work?

Waiting for the new cable, I think I will uninstall the EGS software and try picasso96 drivers using separate monitors and see if I can get it to work.

The GVP likely isn't active unless the RTG drivers are installed and running. Knowing the pinout of the 9-pin pass-thru would be helpful, it could be expecting composite sync while the Indy outputs H+V sync like a typical VGA device. Does the Indy work at all in the machine without the GVP?

NJRoadfan wrote:

Does the Indy work at all in the machine without the GVP?

Yes, it works without problems.

Picasso96 drivers and two monitors gave the same result. The second monitor starts when testing a resolution, but shows only black image.

Inspecting the card I found something though.. An obviously broken ferrite bead, FB4 on the image. It is broken in a way that it doesn't let any current through at all. Could this be it? One end is connected directly to the zorro bus and the other leads on the back side of the card all the way to the output/passthrough circuitry. The undamaged FB3 close to it is probably of the same value, but how to measure this thing to find a replacement?

EDIT: It actually leads current with around 1.2MOhms stable resistance. FB3 has an initial small resistance that disappears quickly. I'm not familiar with how these things should behave though. But pin 10 of the bus delivers 12V, so this seems to be the power supply to the output stage and the resistance from the broken FB4 is most likely the problem.