Has this A500 RAM expansion been butchered?

Bead · 29 March 2011, 14:36

I bought my first ever Amiga (an A500) the other day, and it came with a 512kb RAM expansion, but it doesn't work. After taking a look at it, it appears half of the components have been desoldered off. Can anyone confirm this for me? Or is there perhaps some crazy chance that this is how it's supposed to be, and there's just something else wrong with it?
Here's a couple of photos (apologies for the camera-phone quality):

Thanks for taking a look!

cosmicfrog · 29 March 2011, 14:53

probably the circuit for the clock

cpiac64 · 29 March 2011, 15:04

verify capacitor and bridge

Bead · 29 March 2011, 15:24

Quote:

Originally Posted by cosmicfrog

probably the circuit for the clock

This is what I thought, but there doesn't seem to be a pattern for a coin battery holder, which I believe they normally have.

Quote:

Originally Posted by cpiac64

verify capacitor and bridge

I'm sorry, I don't understand. Are you saying that's what has been removed? If so, what are they, and does the RAM no longer function without them?

Thanks for your replies.

cpiac64 · 29 March 2011, 15:34

remove capacitors for test and verify jumper (sorry no bridge-translate error)

Bead · 29 March 2011, 16:51

Quote:

Originally Posted by cpiac64

remove capacitors for test and verify jumper (sorry no bridge-translate error)

I am sorry, but I still don't quite understand. My knowledge of electronics is fairly limited. Remove the capictors (the ceramic ones, or the bigger one?), and then test what/how?
And according to the manual, removing the jumper disables the RAM.

FOL · 29 March 2011, 16:57

Quote:

Originally Posted by Bead

I am sorry, but I still don't quite understand. My knowledge of electronics is fairly limited. Remove the capictors (the ceramic ones, or the bigger one?), and then test what/how?
And according to the manual, removing the jumper disables the RAM.

You sure the components have been de-soldered, as the top side looks spotless, not a sign of solder.
You would definately see silver not gold if the components were there originally.

Bead · 29 March 2011, 17:06

Quote:

Originally Posted by FOL

You sure the components have been de-soldered, as the top side looks spotless, not a sign of solder.
You would definately see silver not gold if the components were there originally.

It definately looks like components have been desoldered as there are erratic blobs of solder on all the holes, but maybe that's what it's supposed to be like. I'm not sure. I'll try to borrow a decent camera and take some better photos when I get home from work later.

FOL · 29 March 2011, 17:09

Quote:

Originally Posted by Bead

It definately looks like components have been desoldered as there are erratic blobs of solder on all the holes, but maybe that's what it's supposed to be like. I'm not sure. I'll try to borrow a decent camera and take some better photos when I get home from work later.

What normally happens, is the solder runs through the holes, as its multilayer print.

Jope · 29 March 2011, 17:12

It could be they were never there, meaning this was just a cheaper clockless version of the same expansion. The battery (3.6V barrel style) would go into the large rectangular area where it says BT1.

I agree, the soldering looks a bit shoddy at the empty pads, but it could be that this was just a low quality piece of HW. :-)

FOL · 29 March 2011, 17:28

Quote:

Originally Posted by Jope

It could be they were never there, meaning this was just a cheaper clockless version of the same expansion. The battery (3.6V barrel style) would go into the large rectangular area where it says BT1.

I agree, the soldering looks a bit shoddy at the empty pads, but it could be that this was just a low quality piece of HW. :-)

Agree,

.

pandy71 · 29 March 2011, 17:45

Seems that clock area is not populated at all (or parts are removed) - probably still can be used as normal RAM expansion.

Bead · 29 March 2011, 17:59

Quote:

Originally Posted by Jope

It could be they were never there, meaning this was just a cheaper clockless version of the same expansion. ...

I am hoping this is the case, as I do know this expansion was sold in 2 different versions (with and without clock), but if this is the case, then what could possibly be causing it to not work?

Thanks for all the replies so far. Hopefully I'll get some better photos up soon.

orange · 29 March 2011, 18:46

perhaps one of ram chips is defective.

or connector is bad. iirc, KS2+ could show 'board defective' screen. not sure if that would work on this kind of expansion, (i think it did on A590)

Jope · 29 March 2011, 19:27

Board defective is only for Autoconfig devices.

This RAM expansion is not Autoconfig, it is instead detected by exec.library's RAM checker routine. If it detects no RAM or bad RAM, it simply doesn't add it to the RAM pool.

Bead · 29 March 2011, 20:35

I've managed to take some more photos with a better a camera, although the quality still isnt as good as I was hoping.
First, here are the each side of the RAM chips up close (some are out of focus unfortunately):
http://i.imgur.com/1R1CB.jpg
http://i.imgur.com/ydoIX.jpg

And here is the whole unit from above:
http://i.imgur.com/WGxhk.jpg

(I figured the photos would be too large to embed).

I'm thinking I might just try to resolder some of the dodgey looking pins, but I'm not sure if it'll do any good.

FOL · 29 March 2011, 20:52

Quote:

Originally Posted by Bead

I've managed to take some more photos with a better a camera, although the quality still isnt as good as I was hoping.
First, here are the each side of the RAM chips up close (some are out of focus unfortunately):
http://i.imgur.com/1R1CB.jpg
http://i.imgur.com/ydoIX.jpg

And here is the whole unit from above:
http://i.imgur.com/WGxhk.jpg

(I figured the photos would be too large to embed).

I'm thinking I might just try to resolder some of the dodgey looking pins, but I'm not sure if it'll do any good.

Now I would 100% agree, that board is well and truely butchered,

.

pandy71 · 29 March 2011, 20:54

Strange - i think that someone modify this board (repaired?) - memory IC are from IBM (quite rare) and some IC's legs looks weird (slightly bended?) IMO the best is replace all components based on many similar memory expansions...

FOL · 29 March 2011, 20:57

Quote:

Originally Posted by pandy71

Strange - i think that someone modify this board (repaired?) - memory IC are from IBM (quite rare) and some IC's legs looks weird (slightly bended?) IMO the best is replace all components based on many similar memory expansions...

I think it was repaired, didnt work, so all the clock stuff was removed and this board sold on? as working?

Bead · 29 March 2011, 21:03

Quote:

Originally Posted by FOL

I think it was repaired, didnt work, so all the clock stuff was removed and this board sold on? as working?

I didn't buy it as working. I bought an A500 from a flea market, and the board was already inside.

So you don't think resoldering the legs would do any good?

29 March 2011, 14:36	#1
Bead Registered User Join Date: Mar 2011 Location: UK Posts: 34	Has this A500 RAM expansion been butchered? I bought my first ever Amiga (an A500) the other day, and it came with a 512kb RAM expansion, but it doesn't work. After taking a look at it, it appears half of the components have been desoldered off. Can anyone confirm this for me? Or is there perhaps some crazy chance that this is how it's supposed to be, and there's just something else wrong with it? Here's a couple of photos (apologies for the camera-phone quality): Thanks for taking a look!

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29 March 2011, 14:53	#2
cosmicfrog The 1 who ribbits Join Date: Apr 2006 Location: leek, Staffs, UK Age: 56 Posts: 3,557	probably the circuit for the clock

29 March 2011, 15:04	#3
cpiac64 Registered User Join Date: Apr 2010 Location: Italy Posts: 1,136	verify capacitor and bridge

29 March 2011, 15:34	#5
cpiac64 Registered User Join Date: Apr 2010 Location: Italy Posts: 1,136	remove capacitors for test and verify jumper (sorry no bridge-translate error)

29 March 2011, 17:12	#10
Jope - Join Date: Jul 2003 Location: Helsinki / Finland Age: 43 Posts: 9,861	It could be they were never there, meaning this was just a cheaper clockless version of the same expansion. The battery (3.6V barrel style) would go into the large rectangular area where it says BT1. I agree, the soldering looks a bit shoddy at the empty pads, but it could be that this was just a low quality piece of HW. :-)

29 March 2011, 17:45	#12
pandy71 Registered User Join Date: Jun 2010 Location: PL? Posts: 2,747	Seems that clock area is not populated at all (or parts are removed) - probably still can be used as normal RAM expansion.

29 March 2011, 18:46	#14
orange Registered User Join Date: Apr 2007 Location: Belgrade Posts: 567	perhaps one of ram chips is defective. or connector is bad. iirc, KS2+ could show 'board defective' screen. not sure if that would work on this kind of expansion, (i think it did on A590)

29 March 2011, 19:27	#15
Jope - Join Date: Jul 2003 Location: Helsinki / Finland Age: 43 Posts: 9,861	Board defective is only for Autoconfig devices. This RAM expansion is not Autoconfig, it is instead detected by exec.library's RAM checker routine. If it detects no RAM or bad RAM, it simply doesn't add it to the RAM pool.

29 March 2011, 20:35	#16
Bead Registered User Join Date: Mar 2011 Location: UK Posts: 34	I've managed to take some more photos with a better a camera, although the quality still isnt as good as I was hoping. First, here are the each side of the RAM chips up close (some are out of focus unfortunately): http://i.imgur.com/1R1CB.jpg http://i.imgur.com/ydoIX.jpg And here is the whole unit from above: http://i.imgur.com/WGxhk.jpg (I figured the photos would be too large to embed). I'm thinking I might just try to resolder some of the dodgey looking pins, but I'm not sure if it'll do any good.

29 March 2011, 20:54	#18
pandy71 Registered User Join Date: Jun 2010 Location: PL? Posts: 2,747	Strange - i think that someone modify this board (repaired?) - memory IC are from IBM (quite rare) and some IC's legs looks weird (slightly bended?) IMO the best is replace all components based on many similar memory expansions...

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