Amiga 1200 not booting after recap

[roger_xy]

Hi
I just recapped my Amiga 1200 for the first time & everything worked fine when I bench tested afterwards, it booted up to the Kickstart screen, even stress tested.
Then I tried to run the HDD w. the Turbo card but it didn't boot up.

However, now when I've removed the HDD it doesn't boot up to the Kickstart screen anymore. I do get a signal (RGB) with black background and some stuff going on in the background, if I would just take a wild guess I would say it keeps rebooting.

Any ideas where to start the trouble shoot for this?

Thank you very much

 

[miggymad]

Check your Amiga's on-screen colour codes against the list below:

RED	Kickstart ROM error	Two ICs in A1200, A3000, A4000
BLUE	Custom chip problem	Denise Paula Agnus
GREEN	RAM error
YELLOW	Above problems combined
LIGHT GREEN	CIA (U7/U300) problem
BLACK	CIA (U7/U300) problem	If not booting
DARK GRAY	Hardware tested OK
LIGHT GRAY	Software tested OK
LIGHT GRAY	CIA (U8/U301) problem	Stops at gray, CIA defective
BLACK/STRIPES	ROM or CIA
No video	R406 or R215 open R406=1 ohm R215=4.7 ohm
Video scrambled	Agnus or Denise defective

 

[roger_xy]

Thank you for your answer. I made a vid clip of the screen when starting up. Not sure what this qualifies as

 

[Boing-ball]

Thank you for your answer. I made a vid clip of the screen when starting up. Not sure what this qualifies as

First off, check for any Green pins on the IDE. Second, what type of PSU are you using? Could be coincidence that you are now seeing issues after the recap, maybe the PSU is going faulty.

 

[miggymad]

Well, that's a new one for me!

Have you gone and double-checked the recap work for any stray blobs of solder? Focus your investigation area on and around the power caps to begin with.

Make sure you haven't solder a cap backwards. I've seen that before so worthwhile to check.

 

[roger_xy]

This is the board in question

 

[miggymad]

 

[miggymad]

Also, you are missing a cap ....

 

[miggymad]

Should look like this ...

Or maybe not then ... Rev 1B board only it seems

 

[roger_xy]

I think the work around the power caps seem good imo & they are inserted correctly.
That "missing" cap has never been there. This is what it looked like before I recapped

 

[miggymad]

It looks suspiciously like a cap leak has occurred in that area sometime in the past - green and not very nice looking traces!

 

[Bladejack]

C460 is only on rev 1B

 

[roger_xy]

UPDATE
I managed to solve it, or at least I think so. Because after I did a reseat of the Kickstarter roms it now seems to work fine again. I'm not sure if this makes any sense for this problem but (knock on wood) it seems to run fine now.
Thank you everyone for your inputs, really appreciate it!

 

[droopy]

I learned the hard way that it is important to REALLY clean under all caps before soldering the new ones in.
My first 1200 recap I had to do twice because of that. One thing to do is to replace a few caps (and clean) test the MB that it works, then do some more caps.. test and so on. That way it will be easier to find any errors..

Nowadays I have a soldering tweazer that makes things a breeze..