aca620 board pic, comparisons needed
 

Hi all,

I just received this new ACA620 today from Amiga kit and i noticed that the oscillator is crooked, when looking closer at the plcc chip it appears that it has been removed and reattached as the solder joints have excess solder on the pads. The pins on the plcc also have a brown tinge to it... is it just mine that shows this or does anyone else see this on theirs ? There also appears to be excessive grinding of the plcc chip that i'm sure generated a lot of heat. I haven't even plugged it in yet and i will wait for some other peoples comparisons before i do


Looking at the picture on Amigakit shows a nice looking one, it also has a TXC oscillator instead of the Koyo on mine ? Also looking at the edges of the oscillator shows dirt around the 4 sides and it is scratched

http://amigakit.leamancomputing.com/...oducts_id=1102

@Jens... can you comment on this please?

http://www.kipper2k.com/aca620.jpg

this 1s the same


http://eab.abime.net/showpost.php?p=...postcount=2686

see post 2687 for mfilos answer

here's another pic showing a pin with excessive solder. If the board was produced professionally i am sure we should not see this....

http://www.kipper2k.com/aca620b.jpg

PIC being scratched is common with Jens products.
Indeed there is too much solder on the PIC showing like it's hand soldered.

That looks like something I've soldered on 2 years ago. That is not a compliment =)

PIC can fail when it's reflowed like any other part, perhaps it failed and was replaced by hand?

Koyo is a Japanese manufacturer of oscillator blocks, TXC is either Chinese or Vietnamese going by their office locations. Does Koyo have a bad rep?

Crooked oscillator block does suggest a possible knock during manufacture.

I don't know why Jens would bother scratching off the top of the PIC in the first place, not that hard to guess which one it is based on ground / Vcc pins and a few I/O pins.

mfilos said on other thread

It was sanded by default as Jens said to one of his posts. Was the same lot as the ones used in ACA1231 series where he wanted IC sanded to lower the IC's height, being able to mount a heatsink that would have problem attaching to this IC.

A chip by default is reasonably flat, you use paste to take up the microscopic pits and bumps that the metal wouldn't contact by default. If that's been sanded flat to accommodate a heatsink then good sir I claim it to be a fraud because that isn't flat, hand sanded not machined.

Old years, hardware vendors used to sand the IC's for other competitors wouldn't know what IC they user on their hardware.

As I understood, it was not sanded to be flatter, but to be lower. Just to fit under the heatsink.

Lacquer was another good method of stopping people from reworking.

My mistake I took it to be that it was sanded back to allow a heatsink to be fitted to it. Although why wouldn't you just use a gull wing package to lower it?

Im no solder tech but my uncle was and that for sure is hand solder work!:confused

Hand soldering is still a valid form of manufacture if it's done properly. The part is a quad J leg , as long as the solder forms a good fillet on front of the leg and pad plus the same at the back it doesn't matter how it was soldered on. Granted a screen printer is always going to do a better job than the best hand solderer.

There is no heatsink above the PLCC so i think it has been sanded to hide its identity. I am thinking that because these boards had problems with the firmware and were recalled, that the PLCC was pulled and replaced. The Oscillator may have been removed also to make it easier to resolder the replacement, only Jens can confirm i guess.

My original board was sanded before it went for the fix. Maybe the crystal is crooked to allow for a component on the motherboard?

They are sanded as Jens requested that in the past for the GALS to be sanded.
Dunno if the IC company still has old stock for Jens, or the request of his hasn't be changed yet.

Oh my God what is this??? Even components are not positioned correctly... On my designs I take care of dimensions low as 0.001mm and here we all talking about 2 or more mm differences...
I don't believe that he soldered this because it is too unprofessional and looking at this I would never give so much money for it. Kipper2k i have some of your designs and it is much much better soldered than this. About sanding chips I don't see a point of doing that. What if you know what GAL is used it is not important because you don't have the code inserted in it. And those days you even don't need to know what chip is used attach logic analyzer on it and cache signals and replicate it. Maybe few hours of work...

Again, he's not trying to hide which chip he's using:

Also, I think the soldering looks ok. It's not perfect and probably hand-soldered if it's a reworked board and I've seen worse looking factory rework on the A1200 motherboards.

Did you mean liqueur? :D