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View Full Version : A600 recap - bad leakage



mjnurney
30th June 2012, 11:27
I have been sent a rev 1.5 A600 to recap, the faults are black screen (blank) and a flashing caps lock. apart from that no life.

So i have cleaned the board with IPA and scrubbed around the caps with a toothbrush (i always do)

and powered it up again - same no life.

So off with the caps , well the caps have leaked worse than i have seen for a long time. the board is rusty around the ram and the it looks like something has been spilt on it at some point..

The first caps came off very poorly , smelt of rotting fish and have visibly leaked in that area, two lifted the pads off but luckily the via was intact on one but not on the other, the leaking acid from the cap had rotted the top away. I'm sorry to say i had to use a trace wire and follow the track back under the board.

The rest of the caps came without drama although another pad looks a little suspect it is still attached and I'm not messing with it.

The board has yet to be cleaned down again and throughly tested but its nice to see it booting, even though its taken all morning to fix and enforces my judgement that i don't like the A600.

I had to remove the keyboard socket as the two caps their had hardly any pad showing and i used my two mini irons to remove the caps in the end.

So just some tidying up to do and a clean down and then some testing. hopefully it will sail through and work perfectly....

mike.

youtube vid.
http://www.youtube.com/watch?v=4x4dBlr0zrc&feature=youtube_gdata_player
http://www.youtube.com/watch?v=a_mHnzwwF44&feature=youtube_gdata_player
http://www.youtube.com/watch?v=jYpcoLhR91E&feature=youtube_gdata_player

johnim
30th June 2012, 11:32
nice work again mike

,dont you love that smell

mjnurney
30th June 2012, 11:33
yeah the dead fish smell - love it :-(

protek
30th June 2012, 11:37
It's great to read these revival projects. They isnpire me to fix my A600 mobo too.

mjnurney
30th June 2012, 12:05
The funny thing is I have three that I can't fix of my own but I can everyone else's lol

protek
30th June 2012, 12:25
The funny thing is I have three that I can't fix of my own but I can everyone else's lol

Maybe we should swap. :p

mjnurney
30th June 2012, 12:51
lol ive not given up on two but one is stripped for spares

Powerpie5000
30th June 2012, 13:27
I must be lucky as i've had a few A600's and none of them had bad caps... Still not my favourite miggy though :p

lostrego
30th June 2012, 13:59
Ouch, that lift pads & via rework moments should be a very nervousness ones, nice to see a happy ending.

Dead fish smells like victory! :lol:

TheCorfiot
30th June 2012, 14:40
Nice Job Mike

Quite the expert now :thumbsup:

TC ;)

mjnurney
30th June 2012, 14:45
thanks all , mmm expert nah not really but i try :-)

Allen1
30th June 2012, 14:53
That's a great job Mike, I just did my 4 600's and they are even harder to replace the 2 caps next to the keyboard connector than the 1200's. I never thought of removing the ribbon connector till I seen that done on your pictures, next time I will give that a go as I tend to sometimes catch the back sockets with my soldering irons body even when I am trying to be careful and miss the ribbon connector :lol:

mjnurney
30th June 2012, 15:01
yes me too , soldering irons just love plastic :-)

Powerpie5000
30th June 2012, 15:02
Dead fish smells like victory! :lol:

... What if your caps smell like cat pee? I repaired an old Amstrad Mega PC 386SX a while ago and the leaky caps (and battery) had a smell comparable to used cat litter :shock:

mjnurney
30th June 2012, 15:05
im not familiar with cat pee so i can't possibly say :-)

Powerpie5000
30th June 2012, 15:08
im not familiar with cat pee so i can't possibly say :-)

It's one of those smells that becomes very familiar if you have cats, or if your neighbours cats p*ss on your property... And some caps have a cat pee smell to them (once you know what it smells like, you'll most likely never forget :lol:).

FOL
30th June 2012, 16:03
Nice job. I normally remove the phono sockets, much easier to remove them for changing audio output caps.

Might be worth noting that some revs, have a different cap layout on the right hand side of board. I have seen a few of these with leakage that eats tracks away. Causing mouse problems.



im not familiar with cat pee so i can't possibly say :smile:

It's one of those smells that becomes very familiar if you have cats, or if your neighbours cats p*ss on your property... And some caps have a cat pee smell to them (once you know what it smells like, you'll most likely never forget :laugh:).

Aye, tis a smell you never forget. It smells like a male cat marking its territory, lol.

Allen1
30th June 2012, 17:10
@ FOL "Nice job. I normally remove the phono sockets, much easier to remove them for changing audio output caps."

That's another idea I haven't tried, its good to see another great option being aired on this thread. I've done 5 1200's and 4 600's and didn't have the sense to either remove the keyboard connector or the phono sockets, there would have been no chance of melting plastics if I had thought of that beforehand :picard

Fortunately there hasn't been anything really bad so far but I reckon I will be trying both these ideas out next time I change some caps as on my friends 2 1200's when he is ready for them to be done :thumbsup:

Bad_Ad84
30th June 2012, 18:04
I just use aluminium tape which stops you melting them.


Sent from my iPhone using Tapatalk. Please excuse any crazy auto corrects or lack of detail (links to info sources)

FOL
30th June 2012, 20:21
That's another idea I haven't tried, its good to see another great option being aired on this thread.

Indeed it is, I never really thought about removing the keyboard connector until seeing this thread, :).

As for melting plastics, sometimes things are unavoidable.
When I used to work for an authorised sony service centre, sony would allow some damage as changing the jungle chips (as they used to call them) was a nightmare. You would always end up with some damaged print.

Same senario with changing a CIA chips, you either risk damaging print getting socket off or you solder it with socket still attached risking minor plastic melting. Thankfully flux is your friend and helps make life 10 times easier.


I just use aluminium tape which stops you melting them.


Sent from my iPhone using Tapatalk. Please excuse any crazy auto corrects or lack of detail (links to info sources)

Another good idea.

Methanoid
29th July 2012, 21:41
I see many "Recap" jobs on Amigas being mentioned here.. but is it just Amigas that need this. I have an Atari STE and am wondering now.... ;)

mjnurney
29th July 2012, 22:49
Anything with surface mount or thru hole caps from the 70s or 80s needs doing.

Tv's , cd players , computers , camcorders .. Anything really.

I've seen power packs , early LCD tv's , old CRT monitors and Amps all leaking and eating pcbs...

---------- Post added at 22:49 ---------- Previous post was at 22:35 ----------

The best thing to do is to pop the cover off and have a look. Leaking caps will bulge , move, leak and or stain the solder dull at the pads...

Balooga
29th July 2012, 23:46
Will modern Caps do this in 30 years, or is it just how they made these Caps back then?

Methanoid
30th July 2012, 12:49
Anything with surface mount or thru hole caps from the 70s or 80s needs doing.

Tv's , cd players , computers , camcorders .. Anything really.

I've seen power packs , early LCD tv's , old CRT monitors and Amps all leaking and eating pcbs...

---------- Post added at 22:49 ---------- Previous post was at 22:35 ----------

The best thing to do is to pop the cover off and have a look. Leaking caps will bulge , move, leak and or stain the solder dull at the pads...

Does anyone offer a service for Atari STs here? I know the PSU is a good candidate for a refresh but if I was gonna pay someone to sort that might as well get the whole board refreshed!!

hooverphonique
30th July 2012, 21:49
Will modern Caps do this in 30 years, or is it just how they made these Caps back then?

all electrolytic capacitors dry out eventually, but how long it takes varies wildly, depending on quality and use.. A few years ago I did my pc mobo over completely (when it was maybe 3 years old), because it had become unstable, but that model became known to have poor quality caps, so...

Normally one would just get a new one, but I could get the caps for free and do the work myself, so why not ;)

Just did my A4000 mobo as well, btw..

mjnurney
31st July 2012, 21:42
I may do the ST for you , id have to look what's involved...

Mike.

80sFREAK
3rd August 2012, 02:57
Anything with surface mount or thru hole caps from the 70s or 80s needs doing.

Tv's , cd players , computers , camcorders .. Anything really.

I've seen power packs , early LCD tv's , old CRT monitors and Amps all leaking and eating pcbs...

---------- Post added at 22:49 ---------- Previous post was at 22:35 ----------

The best thing to do is to pop the cover off and have a look. Leaking caps will bulge , move, leak and or stain the solder dull at the pads...

I would not say so in 100% cases. Recently i cracked couple of SuperFamicom's as donors. Both made in early 90's and there is absolutely no leakage on SMD caps.
Also i have some Trio and Yaesu stuff from early 80's and late 70's and thru hole caps(ELNA, Nichicon, Rubycon) looks absolutely healthy(i desoldered some to check capacitance).
All units made in Japan, maybe this is the answer.
However later stuff, about 5years old or so, made in China, already showing loosing capacitance. Not half of what was marked on the barrel, but, let's say, few % under claimed value, but older ones usually still +5-10% of the claimed value.

Bad_Ad84
4th August 2012, 18:26
It's 100% of cases that they will leak. Variable is time taken


Sent from my iPhone using Tapatalk. Please excuse any crazy auto corrects or lack of detail (links to info sources)

rkauer
4th August 2012, 21:16
I would not say so in 100% cases. Recently i cracked couple of SuperFamicom's as donors. Both made in early 90's and there is absolutely no leakage on SMD caps.
Also i have some Trio and Yaesu stuff from early 80's and late 70's and thru hole caps(ELNA, Nichicon, Rubycon) looks absolutely healthy(i desoldered some to check capacitance).
All units made in Japan, maybe this is the answer.
However later stuff, about 5years old or so, made in China, already showing loosing capacitance. Not half of what was marked on the barrel, but, let's say, few % under claimed value, but older ones usually still +5-10% of the claimed value.
Good quality capacitors are one of the best approach for maintenance of our loved hardware.

But remember then those spanking brand new pc motherboards that start to fail after two years (some even earlier). The problem is not only the brand, but also the usage and frequency applied to the pieces.

Amigas and alikes are subject to the same problem: the higher the frequency applied to the capacitors, shorter is the life of the units.

hooverphonique
5th August 2012, 15:52
Aye, tis a smell you never forget. It smells like a male cat marking its territory, lol.

how ironic.. in danish, "tis" means pee, and it's not slang either :lol:

Methanoid
5th August 2012, 15:57
Aye, tis a smell you never forget. It smells like a male cat marking its territory, lol.

how ironic.. in danish, "tis" means pee, and it's not slang either :lol:

Offtopic (but its your fault for starting with Danish language!)

Get back to Denmark and make more episodes of Borgen and the Killing.... and while you're at it.. tell me if Danish digital TV has English subtitles available for these?

Tak !! :lol:

You've got some good actors and producers over there.... :D

/Offtopic

hooverphonique
8th August 2012, 20:42
Hmm.. at least not on DVB-T as far as I've seen.. And the online stuff seems to have subtitles "burned in" instead of overlaid by the player..

I hear that some of the newer productions by danish national tv are pretty popular in the uk.. well, glad you like "our" work :-)

is "Borgen" called "Borgen" in the uk as well? I guess that word doesn't make much sense in english..