GVP Spectrum+A1942 display problem

[jagoche]

After a while I have connected my old A1942 monitor to GVP Spectrum. Colours on the display are really PALE! Both, Spectrum and native A4000 AGA modes

If I connect the monitor directly to A4000 video port, the colours are normally bright (right most image).




Images from the left:
1. Spectrum 16bit mode, monitor connected to Spectrum VGA port.
2. A4000 AGA 8bit, passthrough via Spectrum, monitor connected to Spectrum VGA port.
3. A4000 AGA 8bit, monitor connected to A4000 video port.

Is there an explanation, why Spectrum "kills" colours? The problem doesn't seem to appear on LCD monitor.

[rkauer]

 Check capacitors (swap them for new units) and filters (for cold joints) on the out area of the Spectrum.

 If all fails, look for some output transistor.

 If nothing helps, (re)check your RTG system prefs(Picasso96? CGX?).

[da9000]

I was going to chime in with cap(acitor)s myself, but after looking at the card's photos I see they're all SMD and non-electrolytic, so I'm guessing it's something else, but don't know what :-/

Dim or faded look can be caused by lower voltage levels (while colder solder joints will probably cause no picture or signal to show up at all), so maybe some resistors or transistors are messing up?

[jagoche]

Thanks for the tips.

Indeed I had to replace two broken capacitators a year ago. See the post here.

The thing is that while a LCD monitor was connected to Spectrum the picture was OK. The dim look only appears with old A1942.

I was curious if other Spectrum users have experienced similar problems with old monitros?

[da9000]

Oh, I see (LCD vs your screen). I wasn't aware of the exploding capacitor thread either. Interesting! I guess it's better to hear from other Spectrum users.