just got an SE/30

[insaneboy]

and a 4 plusses (so far I've made one working one out of the 4.... think I'll end up with two total, if one of the last three has a working tube)

unfortunately SE/30 has the lines. :-/ one cap popped, just had to be the one near the video didn't it?

Not skilled enough to replace the chip. (hey at least I know my limitations, I'll stick to 60-70's audio gear with my soldering iron)

other than that it's working, nice and clean (other than marks on the case from poor opining skills), seems to have been left a bone stock 8/40 set up.

oh it also had the red maxell battery, still intact! I pulled and tossed it.

 

[insaneboy]

two! Two, working pluses! *muahahaha*

bad solder joint on the analog board.

other two, one had a dead power supply the other has no power supply(and it has a 512k board and back case)

 

[uniserver]

stop being a wuss twist off those 16v/47uf caps and solder some new ones on, piece of cake,

 

[insaneboy]

the caps I can do... the video chip, not so much.

 

[uniserver]

you are pretty sure that is what the issue is? the video chip? not a cap?

 

[CC_333]

Hi,

Bad caps don't generally manifest like that, do they?

Judging from the picture, it does look a bit more serious than a case of bad caps.

Perhaps someone more knowledgeable than I will chime in and be able to figure things out.

Good luck! I know how frustrating broken SE/30's can be!!

c

 

[TylerEss]

I think he was suggesting that the caps next to the VRAMs leaked and damaged the VRAMs. This is a relatively common secondary failure mode for SE/30s.

(Typically, you replace the caps and an SE/30 is fine. If not, chances are it needs either VRAMs or Bourns filter networks but not usually both.)

 

[insaneboy]

The chip marked UA8(I think, was a U and an 8 for sure) was leaked upon, entire chip was covered in shmutz, corroded pins, the works. The rest of the board looks brand spankin' new so the damage was very obvious.

I will replace the caps. If all goes ok(even if it retains the lines) I'll recap the SE/30 at work too which, last checked, still works.

Just need to find someone that can do that chip... my son has claimed it already and wants it in his room, see how my wife feels about that one still would have to get an ADB keyboard and what not(got rid of 99% of my 68k gear years ago, so I'm keyboard less)

 

[highlandcattle]

clean the chip with lemonacid after all the goo is gone clean it with acohol. this will stop the motherboard from corroding further!

 

[uniserver]

you can get some 12Ga solid core copper wire and bend it around your soldering iron, to get chips out, i've done that for ROM chip migrations to replacement HD board PCB's

here is picture of what i am somewhat talking about,



and a video:

My method is a little different, I just bend the copper wire around my 35watt pencil soldering iron,

so it pretty much becomes like a new tip connected to the soldering iron,

My way gets you more hands free.

use a healthy amount of flux, removal and re-installation.

i have 2 irons, so it doesn't really set me back.

 

[krye]

The best thing to do is just clip the leads, exacto knife or dremel. Pull the casing off, then you can unsolder each reaming lead individually.

 

[James1095]

I've never had to replace any chips on an SE/30 board, just remove the SMT caps, give the board a good scrub in warm soapy water and clean off the corrosion with a magic eraser. Install new caps and it'll work fine.

I can re-cap boards for a reasonable fee for those who are uncomfortable doing it themselves.

 

[Alex's Apple Orchard]

I can bring you a keyboard when I'm passing through...

 

[insaneboy]

I can bring you a keyboard when I'm passing through...

my schedule varies a bit so if you know a day before I can tell ya when I'm around. I'll get you the NeXT keyboard, mouse and PB150 while I'm at it.

 

[insaneboy]

you can get some 12Ga solid core copper wire and bend it around your soldering iron, to get chips out, i've done that for ROM chip migrations to replacement HD board PCB's
here is picture of what i am somewhat talking about,

[attachment=0]mqdefault.jpg[/attachment]

and a video:

that looks simple enough. I'll have to see if any of the broken boards I have kicking around have some chips like the one in the SE/30 I can test it out on.

I have Monday off, could be a good project. I'll have the caps done a least(got a bunch of 47uf 35v electrolytic caps I think would fit ok sideways)

 

[James1095]

Why do a hack job when you can get a set of chip tantalums for a few bucks that fit perfectly on the board? It's easy to tear pads off by attaching through-hole parts to SMT pads.

 

[Alex's Apple Orchard]

Sounds good...prob Fri of next week...let me know if you need anything else before I bring it down

 

[insaneboy]

I didn't know they were SMDs...

 

[techknight]

You have a failure on one of the multiplex IC address lines. Fact. There is a conglomeration of PAL circuits/mux arrays in the video circuit, and their primary job is to serialize the bitmap data stored into VRAM, and shift it out locked to the pixel clock. Well of course V/H sync gets generated from the pals too. The other job of the multiplexors is to TDMA the access to the VRAM, so pixel clock serial output and system bus writes to the VRAM dont collide.

But i doubt its the chip. get a jewlers magnifier and look VERY closely at the pins. I bet 1 of the traces has eaten through/broke. On all the SE/30 boards I have done with various issues, bad traces have been the number 1 problem.