B2000 subjected to pain

[chiark]

Bit specialist this, again...

I've got a non-working B2000. Dead as a dodo: the PSU works, however that's it. Check out the thread in hardware problems for more info and progress

Some pics:

The motherboard: looks fairly OK.


Hang on, what's that in the kickstart chip socket?


BUTCHERY! Some ham fisted owner (not me, for a change) tried to change the kickstart with brute force, ignorance, a screwdriver and more ignorance
Socket removed

[chiark]

Cleaned


Fixed (not neat, but there's bloody great gouges on the board!)

[Zetr0]

@Chiark,

My friend, I think those last two link images are broken......

I have tried refreshing the page .... oh.... a few times.... missing hardware pr0n is worth it!

[TheCorfiot]

Originally Posted by Zetr0

@Chiark,

My friend, I think those last two link images are broken......

I have tried refreshing the page .... oh.... a few times.... missing hardware pr0n is worth it!

Priceless

Zetro my dear friend I can't fault it.

@chiark, Nice Mobo & ahem thanks for the pr0n, I think I'm starting to go blind!!!
Ain't she booting up yet????

BTW That is a wierd little PCB by the ROM socket, what is it for exactly & what Revisions does it affect, Basically Why is it there ????


TC

[Fingerlickin_B]

Originally Posted by TheCorfiot

P
BTW That is a wierd little PCB by the ROM socket, what is it for exactly & what Revisions does it affect, Basically Why is it there ????

Yeah, that gave me a bit of "WTFitis" as well

PZ.

[chiark]

Weird.

They didn't work in the first post, so I edited it to split into two posts. Working "for me" now, but as they're from google on a private account they might not for you? Dunno. I'll move 'em

As for that strange thing, well, I simply dunno. Never seen pics of it before on any board revision. I think it's a 6.3 board but it could be a 6.2 given that it's green... God only knows. It's just moving some of the octal latches - my guess is that they'd left some buffering off the board and this was a quick and dirty modification.

[Fingerlickin_B]

Chiark:

I did "open in new window" & saw them.

Are you sure all the traces on the worst-hit end have been fully bridged? The pic isn't from the best angle & it looks like at least one (the worst one) isn't?

PZ.

[chiark]

Short answer: yup.

[TheCorfiot]

Originally Posted by chiark

As for that strange thing, well, I simply dunno. Never seen pics of it before on any board revision. I think it's a 6.3 board but it could be a 6.2 given that it's green... God only knows. It's just moving some of the octal latches - my guess is that they'd left some buffering off the board and this was a quick and dirty modification.

If that was the case then should it have been fitted to all Rev 6.2 / 3 Boards.

I have a 6.2 & 6.3 & neither has the extra board, my reason for labouring on this point is if it was fitted to compensate for a bad batch of 68000, AGNUS.. or buggy components, etc could it now be causing an issue if the offending parts have been replaced.
Just trying to understand why it's there really.

TC

[Fingerlickin_B]

Damn, I'm drunk & was hoping for an easy solution to your problem

Not at you...at me hoping for the easy fix

PZ.

[chiark]

No worries B , and as for what the board is trying to fix it's a mystery.

[chiark]

changed the final 2 pics to be hosted by eab...

[TheCorfiot]

Originally Posted by chiark

changed the final 2 pics to be hosted by eab...

Just Seen the last 2 Pix...

Bloody Hell, I bet the caveman who tried to upgrade the Kickstart was totally stumped why his A2000 refused to work with the new ROM.

heavy rework Man Of course you have carried out full continuity checks for O/C & Shorts, yep I know you have sorry!!!!


TC

[chiark]

Short answer: Yep

I know it's not pretty! But trying to get those bits of wire over the damage zone was a nightmare...

[chiark]

http://www.forum64.de/wbb3/index.php...threadID=18567

http://translate.google.com/translat...-8&sl=de&tl=en

HMm... "Suspect it is to do with Agnus". Oh poo. Back to the original agnus then.

[chiark]

http://eab.abime.net/showthread.php?p=236956#post236956

Verrrrry interesting! Looks like it could be a 6.0 board then? Sheesh!

another clue... It has a RED power LED, suggesting it was originally equipped with OCS and KS1.3, however it has a 2.04 chip in it. And Super Denise.

Blimey, this is strange!

[Zetr0]

@Chiark

I am leaning to believe that this is a reworked or attempted upgrade of a much earlier board, like the 6.0, or perhaps earlier?

still, I cannot figure.... how one managed to put this craters under the kickstart.... oh....

ah..... yeah..... ham-fisted approach with a screwdriver.... sheesh... that was some forced used....

good job on re-flowing the tracks, its never easy on a cratered board my friend. LOL I would of just run 30AWG from point A to point B and ignored the reflowing, but in this case you have kept the lines nice and short

so... come on now my friend.... put us out of our misery.... does it boot?!

[chiark]

Wotcha Z, I've run single strands of wires over the damage to try to fix it... I couldn't get to the other ends of a couple of the connections as they're under chips!

It goes through post, dark grey light grey, white, then... Reboots. Constanty. With a flashing power LED.

It's a 6.x for sure as its got the higher density ram chips... Beyond that, goodness only knows! I am leaning towards pre 6.3 due to the presence of the red LED, however I think it's got the super denise.

This could explain why the 8235 completely foxes it

[rkauer]

Originally Posted by chiark

Wotcha Z, I've run single strands of wires over the damage to try to fix it... I couldn't get to the other ends of a couple of the connections as they're under chips!

It goes through post, dark grey light grey, white, then... Reboots. Constanty. With a flashing power LED.

It's a 6.x for sure as its got the higher density ram chips... Beyond that, goodness only knows! I am leaning towards pre 6.3 due to the presence of the red LED, however I think it's got the super denise.

This could explain why the 8235 completely foxes it

Like I said before: bad Agnus or bad Agnus socket/connection. Or the U302 (a TTL 74LS32 - a 4x OR gates).

[chiark]

Ta
I'm checking all the different Agni I have.

Can I test the 302 in place?