A3000 restart after 10 years having video issues

[mrozlog]

Hello All,

I have 2 A3000(s) and after getting the Amiga Forever 2011 (Premium Edition Upgrade) I decided to go out in my garage and set them back up.

I have one Commodore 1950 monitor and I have a standard VGA 21" monitor.  Both monitors are showing the same behavior, so I believe I can take the monitor is having issues off the table and focus on the A3000.

The first A3000 does not show any video interaction at all, I've checked all of the chips and they appear to be seeded correctly, again it does not matter the monitor I use it remains black.  It does sound like the A3000 is loading as normal the HD is going and sounds like my other A3000 that does have video out.  So I'm sure on how to hunt down this issue.

However, my second A3000 when either monitor is plugged in, it shows vertical scan lines and if I move the mouse I can sometimes see the picture or Workbench 3.0, please check out the attached pictures for what I'm talking about.  Again the chips appear to be seeded correctly, I just don't know what to try next.

Any input or suggestions would be greatly appreciated.

Thanks in advance,

Mike

[Zac67]

Video from the VGA port? Take a look at the battery - chances are that it's leaked badly and possibly destroyed Amber circuitry...

[alexh]

Switch to NTSC mode if possible to get 60Hz. (Should be default for USA A3000)

Try tweaking the Amber trim pot resistor (tiny screw next to the VGA connector, remember how many turns and what direction to return to beginning)?

[mrozlog]

Video from the VGA port? Take a look at the battery - chances are that it's leaked badly and possibly destroyed Amber circuitry...

Actually that looks fairly good, no leakage (very lucky) and I will try to find a new battery and replace both just to be safe.  So Amber is looking good.

Mike

[mrozlog]

Switch to NTSC mode if possible to get 60Hz. (Should be default for USA A3000)

Try tweaking the Amber trim pot resistor (tiny screw next to the VGA connector, remember how many turns and what direction to return to beginning)?

Tried with both the 1950 monitor and the 21" VGA monitor, the video is the same.  I turned the screw clockwise no difference till it clicked, which was about 24 turns, went counter-clockwise 24 and then another 24 turns, no difference, turned it back clockwise 24 turns, so I should be back to where I was before.  

It is still displaying the image like in my attachments.

Mike

[smerf]

Hi,

Whenever I leave my A3000 off for a long time, I get the same, black screen, I leave it sit on for about 8 hours, check it every 2 hours by turning it off and then turning it back on. Usually about the third or fouth time it starts working correctly. I have two A3000's that do this.

smerf

[coldfish]

Dry Caps?

[mrozlog]

Dry Caps?

Sorry I don't understand... Dry Caps???

Mike

[alexh]

Dry capacitors on the motherboard. A component on the motherboard which can fail over time.

Difficult to diagnose. Even more difficult to replace without expert help.

Will probably require sending your Amiga to a repair center. Not sure there is one in the USA... maybe AmigaKit?

Do you have the cable to connect the 1950 to the 23-pin RGB port?  That way you see if it is the AMBER circuit or the Amiga video circuit?

Have you tried the AMBER switch in both positions when the 1950 is connected to the 15-pin VGA connector?

[mrozlog]

Dry capacitors on the motherboard. A component on the motherboard which can fail over time.



Difficult to diagnose. Even more difficult to replace without expert help.



Will probably require sending your Amiga to a repair center. Not sure there is one in the USA... maybe AmigaKit?

MJR:  I will see what I can find

Do you have the cable to connect the 1950 to the 23-pin RGB port?  That way you see if it is the AMBER circuit or the Amiga video circuit?

MJR:  I think I do, I will have to search the house to find it!  :lol:  Since I've not used my Amiga(s) in about 10 years this should be fun.

Have you tried the AMBER switch in both positions when the 1950 is connected to the 15-pin VGA connector?

MJR:  When I click the Enable / Disable switch in the back, there is no difference in the display.

Off to search the house for  the 15/24 converter.

I will let you know.

Mike

[alexh]

You 100% certainly should see a difference when switching the Enable/Disable switch if connected to a VGA monitor (not the 1950) because when off the monitor should not be able to display the horizontal screen refresh rate of 15KHz

Find the adapter dongle and see if that makes any difference... it could help isolate where the fault is on the motherboard.

[mrozlog]

You 100% certainly should see a difference when switching the Enable/Disable switch if connected to a VGA monitor (not the 1950) because when off the monitor should not be able to display the horizontal screen refresh rate of 15KHz

Find the adapter dongle and see if that makes any difference... it could help isolate where the fault is on the motherboard.

MJR:  I did see a little but the overall picture stayed the same.  I'm going to put it back together and try my other box.  Not exactly sure what do try next.

I will keep you posted on my attempts - thanks to all so far!

[mrozlog]

Hi all.  I found the 24 pin converter, plugged it in, and there wasn't any difference in either the 1950 or my other monitor, and no difference when I toggled the switch.  I'm amazed I found the converter (in perfect condition I might add), but since it didn't work, I think I'll go cry now.  I'm not worthy to own an Amiga anymore.  

Mike


P.S. - I even found my original manuals, including all my great game manuals.  My wife and I just want to play some Black Gold again!

[mrozlog]

Just tried the converter with my 2nd A3000/1950 - the one I couldn't get any picture from - and it worked, but the picture is misaligned and the mouse is showing doubles and triples of it.  Any ideas?

Mike

[alexh]

there wasn't any difference in my other monitor

Wow, that means your other monitor is also a 15KHz capable (Amiga) monitor. OR it means that your Screen preferences is set to a software scandouble resolution (like double NTSC).... have a go at changing the workbench resolution if you can navigate to it (or at least identify which res it is set to).

and no difference when I toggled the switch

The switch only affects the AMBER (15-pin) output. It switches between 15KHz (off) and 31KHz (on).

Just tried the converter with my 2nd A3000/1950 - the one I couldn't get any picture from - and it worked, but the picture is misaligned and the mouse is showing doubles and triples of it.  Any ideas?

Hmmm I wonder why you get no picture on the AMBER output?? Find out what resolution you're in using screen-prefs. Try to change it to something else? Have a go using the overscan controls to re-center the picture?