C= A3000T no video from db15

[Opus]

my C= 3000T has a problem (maybe more than one).  I can't seem to get a signal from the video db15 connector, I do get video from the larger db connector to my 1084S.  I am aware of the flicker fixer switch, which seems to do nothing.  Any ideas to resolve this would be greatly appreciated and may even qualify you for a free beer!

[Opus]

also thought I'd state I have this monitor, and I know it works on my peecee.  http://www.superwarehouse.com/3G_Technology_19_LCD_Monitor/GM-190B/ps/629408
I have a gvp spectrum I thought died, but I really think I have no signal from the connector as the spectrum uses that jumper...

[VingtTrois]

Check Amber!

[mechy]

Hi,
  as stated,check the amber chip. Alot of problems can stem from a bad power supply and chips that need reseating. I suggest checking the power supply under load first, if its ok,then tearing it down and reseat every chip.You might also try adjusting on the flicker fixer tuning screw,sometimes these get dirty.

Mike

[Zac67]

If it's not already been cared for: check the battery and remove it if any 'fur' is showing!

[Opus]

quick update.  Battery is long gone and area cleaned. Check power?  I will IF "everything works fine BUT the 32kHz output" could be related to a power issue...  I also tried adjusting the pot for the scandoubler to no effect.  if I use a mediator and a voodoo card, is Amber used?  I take it the video comes thru the zorro and might be unaffected by a bad Amber?

[save2600]

I take it the video comes thru the zorro and might be unaffected by a bad Amber?

Correct. Did you try re-seating all the chips nearby yet? Denise and Amber especially. Don't even attempt touching Amber unless you have the proper puller for it. Her socket breaks quite easily  

[alexh]

It has to be in NTSC mode to produce a picture on most LCD monitors

[Opus]

I pressed Amber in, I do not have a puller and will look for a puller when I order a new Amber.  I did press on all socketed chips, so I'm sure I fondled Denise as well.  Alexh: NTSC is only for native modes iirc, which I am getting output to my 1084S.

[alexh]

Alexh: NTSC is only for native modes iirc, which I am getting output to my 1084S.

It's not a separate RTG graphics card it is a native mode scandoubler. The output is just a scandoubled version of what you're getting on the 23-pin (1084s).

Whatever mode you're in (PAL/NTSC) is what you get on the 15-pin output but with a Horizontal refresh of 31KHz rather than 15KHz.

If you are in a PAL mode the vertical refresh rate will be 50Hz, which is outside the capabilities of most modern monitors. You need to switch to NTSC to get 60Hz before most LCD monitors will work.

I bet money there is nothing wrong with your AMBER chip.

[Tahoe]

If possible try and test a CRT VGA monitor. I have seen LOTS of LCD monitors which will not sync down to 31Khz properly. Does the monitor jump on but tell you the signal is out of sync? Then the likely cause will be it does not sync down low enough for the scandoubler to work. Only fix would be is buying an Indivision ECS or trying to source a TFT that will. Although that is becoming harder by the day!!

[alexh]

I have seen LOTS of LCD monitors which will not sync down to 31Khz properly.

Strange. I've never seen this. I thought every monitor was rated to 31KHz?

I've seen something similar with the software DBL_PAL and DLB_NTSC screen modes (even with CRT) and you can improve it using the VGA monitor driver but I've never seen it with a hardware scandoubler in NTSC mode (60Hz).

trying to source a TFT that will. Although that is becoming harder by the day!!

?? All LCD's are TFT aren't they?

[Tahoe]

Strange. I've never seen this. I thought every monitor was rated to 31KHz?

In theory, Yes. I have found the problem to be related to most modern LCD's not syncing down to 31.4 Khz, usually they need a fraction higher. The 50/60hz for NTSC/PAL usually isn't a problem.
I have a bucket load of TFT's that won't run under the A3000 native scandoubler, nor older external ones. The Indivision ECS/AGA and Picasso IV work, although the Picasso out-of-the-box won't work unless you up the frequency using PicassoModeTNG.

I have found so far:
HP L1940 won't work
HP L1955 won't work
HP L1520 (oldie) works
Samsung T200 won't work
Hercules Prophet 920 works

?? All LCD's are TFT aren't they?

I meant finding one that sync down to 31.4...

[alexh]

Interesting...

For me it has always been the other frequency... the vertical. Most LCD panels are rated to 56Hz vertical and so don't sync to PAL refresh rates.

[Tahoe]

Interesting...

For me it has always been the other frequency... the vertical. Most LCD panels are rated to 56Hz vertical and so don't sync to PAL refresh rates.

Interesting indeed, I think I need to look further into this, maybe I am mistaken and it is indeed the horizontal... I'll set the jumpers on my 3000T to NTSC and retry...