A trip to my storage shed - Two a1200's need help!

[ElectroBlaster]

Well I finally did it today, actually went into the storage shed and found two old a1200's that need a bit of tlc.

Im really confussed about why I took a 1d.4 board with timing fixes and 3.1 roms and shoved it in a rather manky case and a yellowed keyboard
I mustve had my reasons back in the mists of time

Still I cracked her open and had a good nose around. seems ok apart from a few things that caught my attention. Near where the modulator sits you have two capacitors. They look flat on top but im not sure about the base of each one. they are sitting tilted instead of upright, there is also the tale-tale smell of capacitor juice also one of the solid caps looks bulged. Now I seem to remember this beast worked fine many years ago but I have yet to fire it up and see for sure. I wrote the value of the caps down, these sit around the ide header, modulator, psu socket etc:

solid cap - 6.3v 100uf
blue electrolyte - 6v 470uf
black electrolyte - 10v 1000uf

Can I replace these? or would it be better to recap the entire board?

Second up we have a fairly nice white 1200 with a white keyboard, two keys on the numeric pad are yellowish... mustve have pilfered some keys at one time or another...

This one has a 2B mobo which if memory serves, kinda dies for no reason. I may have asked about this one years ago but never got around to solving it.
Nothing seems to out of place. the caps all look good, no burnt tracks or scorch marks on any chips... I will confirm later by firing it up and seeing what it does exactly. From what I can recall it will work fine for a while and then just go blank, m8 of mine had it and I took it off his hands as a favour.

[kipper2k]

Originally Posted by ElectroBlaster

Well I finally did it today, actually went into the storage shed and found two old a1200's that need a bit of tlc.

Im really confussed about why I took a 1d.4 board with timing fixes and 3.1 roms and shoved it in a rather manky case and a yellowed keyboard
I mustve had my reasons back in the mists of time

Still I cracked her open and had a good nose around. seems ok apart from a few things that caught my attention. Near where the modulator sits you have two capacitors. They look flat on top but im not sure about the base of each one. they are sitting tilted instead of upright, there is also the tale-tale smell of capacitor juice also one of the solid caps looks bulged. Now I seem to remember this beast worked fine many years ago but I have yet to fire it up and see for sure. I wrote the value of the caps down, these sit around the ide header, modulator, psu socket etc:

solid cap - 6.3v 100uf
blue electrolyte - 6v 470uf
black electrolyte - 10v 1000uf

Can I replace these? or would it be better to recap the entire board?

Second up we have a fairly nice white 1200 with a white keyboard, two keys on the numeric pad are yellowish... mustve have pilfered some keys at one time or another...

This one has a 2B mobo which if memory serves, kinda dies for no reason. I may have asked about this one years ago but never got around to solving it.
Nothing seems to out of place. the caps all look good, no burnt tracks or scorch marks on any chips... I will confirm later by firing it up and seeing what it does exactly. From what I can recall it will work fine for a while and then just go blank, m8 of mine had it and I took it off his hands as a favour.

Recap the whole board, sometimes caps will not show any physical damage and still be toast.

Second Amiga could have a cold solder joint on any one of the chips, run the Amiga, ground yourself on the metal casing and either touch the top of all the chips to see if you have a hot one, or use a temp probe. probably fixable. (Also check power supply, they sometimes get "tired". (Recap that one too

[ElectroBlaster]

Well last night was fun!

The 1D.4 board works but smells rancid when powered up, the smell is coming from those dodgy caps I listed.

The 2B seems to work but after its been on a while the keyboard decides to not register key presses on random keys.

I could probably recap the 1D.4 but the 2B might be a llittle beyond my scope, havent got the right tools. Time to grab Zetro meethinks