Classicamiga Forum Retro Edition
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Thread: Amiga 600 - Black Screen / Caps Lock On
penrods 17:29 12th February 2013
Hi there,

New to the forumm just got me my first Amiga, an Amiga 600 in an absolutely immaculate boxed condition, however...

I'm guessing this is leaky capacitors from what I already read on the internet but when I've examined the board there is no sign of leaky fluid anywhere?

Any help/suggestions appreciated!

Stephen Coates 18:11 12th February 2013
Hi Lee. Welcome to the forum.

I can't say what is causing your problems, but the fact that the Amiga does eventually work suggests that there's nothing major wrong.

If it is capacitors, they may not leak fluid. Not sure I've ever really seen them leak stuff unless there's something seriously wrong with them. However, some, particularly electrolytics, can just become bad due to age, temperature etc. With electrolytics, the ESR can increase considerably making them useless, and other types of capacitor can end up with the actual capacitance changing over time.

Do any of the capacitors look like they are bulging?

Also, what model is the Power Supply? Are you able to test the voltages coming out of it? Maybe have a look inside to see if the components inside are OK. It may not be a PSU problem, but it would be worth ruling out.

An alternative is that if it's not been used for a long time, it might just be struggling to come out of hibernation, and needs some time to adjust to being used again. Maybe keep trying to use it over the next few weeks and see if it comes to life again!
penrods 19:55 12th February 2013

Thanks for the welcome!

I've now had a closer look at the board having figured out how to get out the case...Have found one Capacitor which looks dodgy, a sort of dark liquid is visible...


It seems that the capacitor I need is of type 22μF x 25V which means nothing to me although I'm no stranger to a bit of soldering - can anyone please recommend what I need from ebay to repace this? (I'm in the UK).

Stephen Coates 20:25 12th February 2013
Hmmmmm. Doesn't look too bad but it might be worth replacing anyway just to see what happens.

There's heaps of capacitors on ebay, but just had a quick look and this will do

They are not surface mount like the original but should be easy enough to solder in place. It'll do just to see if it makes any difference.
Harrison 12:37 13th February 2013
Something that hasn't been mentioned, and 2 common issues that can cause an A600 to have a really long black screen before doing anything..

1, what version of Kickstart rom is fitted? If it is a 3.1 rom these can sometimes take ages to initialise. The A600 would have originally had a 2.0 rom installed.

2, does it have an internal hdd fitted? Some old hdd's can have a really long spin up cycle that takes longer than the Amiga takes to do its initial bootup cycle and so the Amiga gets stuck waiting for it and needs to be soft reset.

3, does it have a 1MB ram board fitted in the trapdoor expansion? These can go bad due to onboard batteries and/or fitted somms going bad. If there is one remove it and see if that helps.

Which brings me to a final question. When you do eventually get the Amiga to work, what does it do when you soft reset it? (Ctrl+Amiga+Amiga).

Just to mention. If you do replace the capacitor, when you have removed the old one, if it looks like it has leaked remember to neutralise the leak and then clean it up before you replace it with a new one. Lemon juice should be good for this, followed by isopropyl alcohol to clean it after.
Tiago 13:45 13th February 2013
Just some more info:
- Leak is not always visible, depends of capacitor, but most times you can see it, it depends of the PCB, it could be dark blue, almost grey/black or dark green/brown.
- Capacitors were made to last for 10/15 years maximum, so every Amiga should have a caps problem it is just a question of time, even if you do not do anything, you don't plug in the miggy, caps will die.
- After change the Cap, the screen image will probably be a bit bad, because new caps need a few minutes to be fully operational.
- If you are going to change one.... change them all. Most likely they will give you problems sooner or later.
Kin Hell 13:32 14th February 2013
Probably a Capacitor issue from the brown ooze there on your pic. This goo get's into the tracks and eats away at them eventually. Best get it looked at before it becomes terminal. - If you're not up for the re-work yourself & you aren't already a member @ Amibay, there are some guys over there that do this kind of re-work for reasonable fee's. Hikey is one of several such guys iirc.

Good luck.
DonAmiga 09:42 18th February 2013
I see Amigakit are selling cap-kits supplied with their motherboard location,
Kin Hell 09:28 19th February 2013

Someone still owes me a phone call.
DonAmiga 23:08 19th February 2013

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