No video on power up on A600

[jbenam]

Hello fellow Amigans :)

Recently, lurking this forum and reading on the web of those fancy IDE to CF adapters, I finally decided to get one for my A600 (KS 2.05 Rev 37.500), but before that, I wanted to check if my Amiga was all right (the last time I used it was one year ago).

The Amiga has stayed all this time in a closed closet on the outside (not directly under the rain, though), so it might have got some humidity.

I remembered that the PSU did not work, so yesterday I opened it and soldered again a desoldered wire. After that, I powered up my A600. Then something strange happened.

The Disk LED is turned on all the time (that's strange, seeing I don't have an HD in it... yet) and there's no image on video. After opening my Amiga, I found that a LED cable was desoldered. After a quick soldering, nothing changed. Oh well, that's not the big problem right now.

The big problem is the video. The Amiga seems to work normally, as I hear normal disk boot and I've even tried loading a disk in it. But no video.

Sadly, I've lost the RF to Aerial cable and the Video port to SCART cable, so I'm just using a composite cable for the moment. I've also tried spraying a bit of Contact Cleaner on the Composite outs, but still no dice. It also seems that the audio connectors don't work too, but I'm not too sure about that.

Someone got any idea or knows the problem?

Sorry for the long wall of text... And thanks to everyone willing to lend some help to an old Amigan :)

[Harrison]

Hello there and welcome to classicamiga.

I'm also having a similar problem with my A600. It was woring perfectly until today. Then this morning I tried to fit a 3.1 rom and the A600 wouldn't boot. No video output and the caps lock light is constantly on. Not sure what the problem could be.

If I get it working I will let you know what I did in case it helps you get your's working too.

[jbenam]

Hello, thanks for the post. The only capslock problem I had was that it was blinking all the time, there were two loose wires on the led panel and resoldering them fixed it.
That incidentally fixed also the Disk Led Always On problem :P So only one more problem to go now.

Returning to the main problem, the video, using some contact cleaner I've been able to get some image on the screen every now and then (btw, I'm using an LCD screen... I remember to hear about flickering problems, it might be this?) for a fraction of a second. And it seems the Kickstart works good enough, seeing the Amiga also loads floppys correctly, more or less.

I tried resoldering the Composite Video Connector (thinking of a cold soldering), only to find that the image appears more rarely now. Oh well, maybe I should only continue using contact cleaner and hoping it solves the problem :)

Even the slightest hint might be useful to solve this problem, so if someone has any ideas, please post them :)

Thanks again for the help :)

[Zetr0]

jbenam

I am wondering if its possible that your amiga could be an NTSC version and hence why its not working properly with your monitor.... hmmmmm

[jbenam]

jbenam

I am wondering if its possible that your amiga could be an NTSC version and hence why its not working properly with your monitor.... hmmmmm

It is an A600 made in the Philippines, and it is marked as an "A600 IT" on the bottom of it. Having bought it years ago in a country where the TV standard is PAL, it's probably a PAL one :) Also I'm pretty sure a lot of my past TVs were PAL only. Can't be certain of it, though.

BTW, I don't have CRT TVs or monitors anymore, but only LCD ones...
Maybe the Amigas have problems with LCDs I'm not aware of?

[Teho]

I know that my LCD monitor does not support standard PAL TV resolution anyway. If I try that in WinUAE and go fullscreen, my monitor just goes black. Could be your problem right there.

[jbenam]

I know that my LCD monitor does not support standard PAL TV resolution anyway. If I try that in WinUAE and go fullscreen, my monitor just goes black. Could be your problem right there.

Sadly, my multi-standard LCD does exactly the same. And during this week there's not a single shop opened which sells contact cleaner. Oh well, I believe I'll have to wait and then see what happens with a LOT of contact cleaner.

Thanks for the suggestion anyway :)

[Zetr0]

@jbenam

what make / model of LCD TV do you have? does it have an RGB SCART input as well as composite?

does it have a 15KHz VGA compatible input?

tap up the LCD TV model here and i can have a lookie around for you.

[jbenam]

@jbenam

what make / model of LCD TV do you have? does it have an RGB SCART input as well as composite?

does it have a 15KHz VGA compatible input?

tap up the LCD TV model here and i can have a lookie around for you.

Thanks, it's very kind of you. Yes, all of them have an RGB SCART and Composite.

I don't know about the VGA frequency, sadly :/

The last one I used was a Samsung SM225MW. When the A600 is powered on, it does a bit of something that looks like static on the screen and then nothing.

[jbenam]

Sorry for double-posting, but I've got some news.

I've got a hold of an old RGB-to-SCART cable... And with that, the Amiga works great. In the worst case, I'll have to build one and stick with SCART (even if I would REALLY prefer Composite...).

I even thought of buying another A600 motherboard, but seeing my Amiga only has a small issue (the component-out) it doesn't seem the case to do it.

I've tried to clean the contacts again and also resoldering some connections. Still nothing. What could ever be that makes the RGB cable work, but not the
Composite-out?

Another way to resolve this issue would be using the RGB port, and creating a D-Sub to Composite cable.
Is there a way to build a RGB-to-yellow composite? Someone knows where to find the necessary pinouts?

BTW, the yellow always-on DISK led was caused by a bridge created by the floppy drive on some ICs under it :P

Thanks again for your time and efforts :)

[Zetr0]

@jbenam

I am a little confused, RGB Scart is uncompressed Video... composite is a compressed video source that is drastically inferior to RGB. why would you want this?

on the Amiga 23pin RGB out there is no composite signal, just composite sync I am afraid to say, however should that you want you could use an A520 Modulator from an A500.

(you can get them from www.amibay.com for around 5 Euros from McVenco, go sign up and post an interest :D) this would give you composite (aka composhite) output for the miggy via 23pin RGB port.