I have some trouble installing my sprinter hardware. When i started the computer for the first time the screen was just black, and nothing happens except for the keyboard lights blinking randomly. After pressing the reset button, still nothing happens on the screen and the keyboard lights are still flashing. After turning the computer on and off a few times, i finally get to the start screen, but the picure is very dark, and i get no colors. Sometimes the keyboard doesn't work. I've managed to get the computer to detect the floppy only once so far. Does anybody know what's wrong?

the power supply??
You can check the voltage with a tester ?

I've now tried replacing the power supply with one from another computer. Same results. I've also tried replacing the 4mb memory with one from my pc, and it didn't do much good either.

A few times i have gotten as far as zx spectrum mode on the machine, though the screen was very dark and without colors. A couple of times i got random pixels all over the screen and the keyboard stopped responding. This suggests that it might be a memory problem of some sort? I will try changing places of the graphics memory chips just in case.

What kind of display was used? If it's TV with SCART, that there is a some problem with SCART cable for some TVs. In my case I remake SCART cable (additional ground pins) and everything was ok.


Alexander Shabarshin (shaos@mail.ru)

I am using a tv. Which of the pins on the scart connector did you connect to ground?

sound ground - 4
blue ground - 5
green ground - 9
red ground - 13
video ground - 17
video/rgb switch ground - 18

if I think right that PetersPlus SCART has the only ground pin. It's works on TV from China, but don't work in european TV (I have "Thompson").


Alexander Shabarshin (shaos@mail.ru)

Yes, you are right.
But some time ago we began to ground other pins too.
Any way the image of Sprinter video cable you can see at www.petersplus.com/download/sp_vcab.gif


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PETERS PLUS LTD

I've now had the time to examine my scart connector cable and compare it to the image of the sprinter video cable on the home page. These are the differences:

- All the right pins on the scart connector are grounded, except for the scart connector metal housing.
- Video connector only has pin 1 connected to scart ground. Not pin 2 and 3.
- Left and right audio are not soldered on the video connector.
- 300 ohm resistors on the image seem to be 390 ohms on my cable. (don't know if this matters). Like in the image they are connected to pin 16 and 8 on the scart connector.

I do not know if any of these differences matter for the problems i have. Any ideas?

- All the right pins on the scart connector are grounded, except for the scart connector metal housing.

Sorry, what numbers it has?

- Video connector only has pin 1 connected to scart ground. Not pin 2 and 3.

No differences. These contacts are connected on the mainboard. Lowest hitch level will be present when these contacts are connected in the video connector. But this is not your case.

- Left and right audio are not soldered on the video connector.

Yes, it is. Audio contacts was not soldered. You need it if you use monitor (or TV) speaker only. And it will created hitch if you use external active speakers. We recommend to use external active speakers for high level of stereo sound.

- 300 ohm resistors on the image seem to be 390 ohms on my cable. (don't know if this matters). Like in the image they are connected to pin 16 and 8 on the scart connector.

No differences. We can use 300Om-1KOm.

So, some differences are present but real problem not found.
You can try to ground all contacts which need it.
And do you sure that your TV SCART has RGB inputs? Did you use this SCART connector with another devices?


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PETERS PLUS LTD

The scart connector metal housing seems to have pin number 21 on your illustration. Pins 18, 17, 13, 9 and 5 on the scart connector are grounded like they should be.

I have used this television set with with amiga computers with rgb cable without trouble.

Let me ask again about the audio. Should i leave them not connected in the future?

The instability also worries me. It seems very much like memory failure. I suspect a glitch in the simm memory slot soldering. Based on what i have told so far, what is your opinion?

Thanks for your help.