Top 10 reasons of broken amigas: Affected parts incl. troubleshooting

[Allen1]

I must admit that I haven't had to replace a leaking cap on any of the 600s or the one 1200 that I have, but its a different story for PC motherboards where they have swelled and either the top of the can starts to give or the rubber seal on the underside starts to come out. These are generally the larger sized radial caps, especially around the processor socket, you do get the odd smaller ones now and then too. Fractures in the solder in PC power supplies around component legs is another common problem.

Sooner or later though, I will change the caps on my Amigas, but only when things start to go wrong and they do need sorting.

[FOL]

Originally Posted by Allen1

I must admit that I haven't had to replace a leaking cap on any of the 600s or the one 1200 that I have, but its a different story for PC motherboards where they have swelled and either the top of the can starts to give or the rubber seal on the underside starts to come out. These are generally the larger sized radial caps, especially around the processor socket, you do get the odd smaller ones now and then too. Fractures in the solder in PC power supplies around component legs is another common problem.

Its a sad shame, that nearly all manufacturers cut costs / corners.
They have a habbit of using caps with 85Deg rating in stuff like PSU's.
This is the only reason they fail. If they had stuck 105Deg caps in stuff, you would not get this problem.

Other problems that can cause venting, is using under rated PSU. The caps in psu vent, causing ripples on the DC line.
This in turn takes out the caps on the mobo. Not a nice death, even for a PC Mobo, .

Originally Posted by Allen1

Sooner or later though, I will change the caps on my Amigas, but only when things start to go wrong and they do need sorting.

Aye, if it aint broke, then dont fix it.
Alot of problems are caused by un-needed messing.

After working 11 years in the electronics repair trade.
I can safely say, radial 105Deg caps will always be my main choice.
Never really get any problems from them.

[Paul_s]

Originally Posted by Allen1

OH NO! Paul have you been sniffing the battery acid fumes

The day after Christmas Paul's true love said to him,
if you don't stop these poems, every things going in the bin
Sniffing battery acid is bad,
I think its made you mad
You're really making me sad,
And I thought this was just a fad,
Oh look there's smoke coming out your tower,
do you think I should turn off the power?

I wrote that crap sat at my desk in work at 7.30am this morning. Please someone phone the mental health services! I recall me being annoyed typing all the days of christmas out as well!

[Allen1]

Originally Posted by FOL

Its a sad shame, that nearly all manufacturers cut costs / corners.
They have a habbit of using caps with 85Deg rating in stuff like PSU's.
This is the only reason they fail. If they had stuck 105Deg caps in stuff, you would not get this problem.

Other problems that can cause venting, is using under rated PSU. The caps in psu vent, causing ripples on the DC line.
This in turn takes out the caps on the mobo. Not a nice death, even for a PC Mobo, .



Aye, if it aint broke, then dont fix it.
Alot of problems are caused by un-needed messing.

After working 11 years in the electronics repair trade.
I can safely say, radial 105Deg caps will always be my main choice.
Never really get any problems from them.

Hi there Fol,

you are certainly right about the use of lower temperature caps for cheapness, maybe the designers didn't take into account that things like the heatsink and fan on CPU's would get clogged with dust over time which in turn would reduce the airflow around the surrounding components. Or it could be the actual manufacturer who changes the specifications to fit within a given price range for the product, either way it does mean that a component failure will more likely happen at an earlier time compared to what it would have been if the higher temperature range was used.

When you think of PC motherboards and what a buyer is going to fit on it and what level of ventilation would the case have etc, you would think that with all those unknowns, the manufacturers would use the best quality caps fit for the temperatures that could be expected within reason.

I hadn't thought about the extra ripple effect from the power supply when the smoothing capacitors have fractured solder around their connections, add that to the load that the motherboard caps would normally smooth out and its looking pretty bleak for the motherboard.


What you say about not fixing things until they are actually broken is so very true, more problems are caused that way and can sometimes be harder to trace if someone has been tinkering instead of leaving well alone but I know that myself and probably most of the folk here, have found that out the hard way at some point in time

This is something that you will already know but may be handy for others.
Its surprising how hard it can be to remove some of those caps due to the large ground plane even with a pace desoldering station, the trick I learned from a card repair operator where I used to work was to also use a soldering iron near the via to reduce the heat loss so that the desoldering iron could melt the solder and suck it out of the via. That works a lot better than taking too much time and overheating the via and causing damage, still takes a bit of practice now and then though.



@Paul,

I rang the local mental health services and told them of your plight, they said Oh NO not Paul, last time we went to help he had us singing Christmas carols for hours.
Those poor staff members start to twitch and stammer when they hear his name or Christmas or carol but especially Amiga. Oh dear they have heard Paul's name being spoken and have gone into the foetal position under their desks and are muttering something about partridges! After that they just went AAAAAARGGGGGGGGHHH and hung up.

Bloody hell Paul, I wish I was that popular


@Dreedo,

the TV modulator is also one of the common faults, especially when you buy a second hand Amiga where someone has been trying to tune it into their TV and damages the threads on the tuner. (thank goodness for the RGB side of things)

[StarEye]

I've managed to ruin the RGB port of two amiga 1200s by accidently shortcircuiting them by trying to blindconnect the AV cables.

I will not do this again. However, anyone know if there's an easy fix to it?

[cosmicfrog]

On the eighth day of Christmas,
my true love sent to me
Eight Frogs a-Ribbiting
Seven copies of Moonstone valued at £200 each,
Six CD32s,
Five leaking capacitors,
Four Amiga 1200s,
Three Amiga 2000s,
Two Amiga 500s,
And a partridge in a leaky barrel battery.


there fixed

[fitzsteve]

Originally Posted by alexh

Everyone says this but I've never seen one in the flesh with this problem (yet).

This is what a leaky Cap did to my A3640

[Paul_s]

reason #5678 people who meddle with stuff that worked fine once upon a time