no boot with video

[Jimmy]

Hi all

I have recently dug around my father in laws attic during a clear out an i have been lucky enough to find myself now in possession of a A500 rev 6a that had intact warranty seals.

After a few funny start ups i had to break into the old girl to have a peek at least to check if there was a battery in there and stop it leaking. So after replacing the caps on my floppy drive cleaning and greasing it so it will read disks consistently, she has died. Or at least it takes a LONG long while for the disk to appear on the screen.

I have a few problems with her the RF 520 module, seems to not work any more or shows a really fuzzy bad screen. I have to now use the mono out, that is clear, or was, to see the boot disk on screen, but now it doesn't boot so no color codes.

One of the caps near the video output has blown. I have ordered a whole new cap set to replace all the electrolytic caps on the main board, hopefully that will sort the video out when i do get it to boot.

but right now its not booting after feeling around i noticed the gary chip was cold and i did a video on it so you could see it in thermal to confirm no heat. i want to test gary. but i have no clue what pins are power and ground etc.

any help would be great for figuring this out here is a video link

[ Show youtube player ]


thanks

[chip]

Welcome to the forum !

[Jimmy]

Cheers mate yeah kinda got straight into it didn't. I was up late last night and was poking around it to try some resuscitation still nothing. What Amiga do you have ?

[chip]

No real hardware mate, just emulation (since 2002 i use WinUAE)

[Jimmy]

Fair enough prob the best way to go what with old hard ware.

Tho I think a lot of good things can be said when comparing old computing experience vs new and that goes for games as well.

Are there any electronic diagrams on this site for the 500 think I'll have to probe the pins about on Gary. See if I can get a pulse.

I noticed the kick ROM was cold as well.

[Clockodile]

Originally Posted by Jimmy

Fair enough prob the best way to go what with old hard ware.

Tho I think a lot of good things can be said when comparing old computing experience vs new and that goes for games as well.

Are there any electronic diagrams on this site for the 500 think I'll have to probe the pins about on Gary. See if I can get a pulse.

I noticed the kick ROM was cold as well.

Amiga 500 schematics aren't super tricky to find. (the official service manual, if it existed, is pretty much impossible to find) For instance, you can find official schematics on the (Amiga) file server (search for "Amiga 500 schematics" and remember look for the second title page for schematics relevant to your board rev and you can find fan revised schematics for your board here.

[B2k_ad]

Hi.

Recap the thing, clean all legs of the Custom Chips, reseat them all and you should be Good.
The feel Methode does not work on Garry or the Rom.
They stay Cold.
If Garry was bad the system most likely wouldn`t do anything at all.
The same goes for the Rom.
If all of your caps are bad to the point of some of them are blown up, there is no wonder you get a bad video signal.
Though i advise against any further operation without propper Capacitors,: if the Amiga is waiting a looooong time on boot until it presents you the Kickstart screen,
that normally has to do with it thinking it has a Disk present in it`s Drive.
This is usually the fault of the little swich that gets pressed while a floppy disk is in the drive.
Since this is normally closed , it is supposed to make contact while there is no disk in the drive.
After all those years it usulally does not.
A spray of WD40 solves this problem for a few months at least, also regular use would help gettimg it back to life.

If any of my text format is off, please blame it on my A2000.
Actually Thats the only Computer i Use to write in this Forum.