A3000 problem

[SteveSMS]

Hi guys,

I have a little problem with my A3000D.
It's a standard 3kD, though it says 2.0 roms on bootup (the floppy screen)

The problem i'm having, is that my screen looks untuned. I can recognize Workbench and the Insert Disk screen, but there are "shifting" lines on it. I'm using the built-in scandoubler.

If i hook it up through scart on a regular Scart monitor, i get a  rolling picture.

Any idea's?

-Steve

[Jeff]

Try the small adjustment pot on the rear of the A3000 in between the 31khz port and the enable/disable switch.

[Effy]

First he hooked it up to a tft but nada. The he connected the computer to a standard 17" CRT pc monitor and got the Workbench screen but very vague, like the monitor had problems getting it on the screen, like the signal needed some finetuning, does that exist ? Can you adjust the vga signal ? Steve has disconnected every card and every harddrive connected to nothing that could cause problems would be connected, but no better result. He thinks the scandoubler is dying so I suggested him to ask for help.
The A3000 belonged to me until yesterday evening at the meeting of BelgianAmigaClub where I swapped the A3000 desktop with several Ram cards and Vlab and Micronik tower with busboard and some other stuff against his Efika with gfx card. If it turns out that the A3000 does not work then I shall of course make sure he will get a working computer but at this point I just hate to give up  :-)

[SteveSMS]

Well i tried the pot on the back, but it's a no go.
Still get the same screen.

[countzero]

did you check normal vga out ? can you try to connect it to a tv or something through 23 pin rgb port and a a520 ? maybe it's not the scandoubler.

[amiga92570]

Did you look at the board and check for battery acid damage on the motherboard. This is common when acid slowly eat the motherboard and surrounding chips. You could also try reseating the chip, possibly a bad connection. Last resort is pull out the old schematics.

[Effy]

He did check the battery and according to him it looked pretty good. He also connected the rgb video port to a rgb monitor and only could see rolling bars ...

[SteveSMS]

^ what he said ^    :lol:

[Boot_WB]

I know you've tried adjusting the trimpot, but it does still sound like the ill-tuned deinterlacer.
Did you try adjusting the trimpot when the computer is switched on? This will allow you to see whether tuning is having any effect at all.

Will connecting to the RGB port give you non-scandoubled output? Does Amber affect the 23-pin output? If not, then it is not surprising that you get the rolling bars from that port.



Regards



Rich

[Zac67]

Amber does nothing to the 23pin/15kHz port. It directly outputs Denise' modes - usually 15 kHz.

You can use a TV's SCART input for 15kHz (with an appropriate cable), though some LCD monitors/100 Hz tubes don't like the signal.

When you turn the phase adjust screw on the back, you should see some change in the video. Maybe the variable resistor is stuck at one end? It gives low clicks when the end is reached.

Or maybe something very simple: is the RGB monitor running the same standard as Miggy? PAL output on an NTSC monitor might roll vertically but can usually be adjusted.

How do the lines look like? Vertical, horizontal, stable, flickering, wandering?

[SteveSMS]

Well, the Philips monitor works perfectly on my A500 and my A1200...

the lines i see are flickering...

Maybe i can try and switch it to NTSC or PAL?

[SteveSMS]

It's fixed!

Effy hooked me up with an internal scan doubler, so now it works perfectly.

Thanks, Effy!