Viva la revolución! - 2 troubled SE30s

[doug.smith]

Anyone who can support with some advice/direction, I will very much appreciate it!​

Here are the facts:

- Both SE30s have professionally recapped logic and analog boards.  Only the power supply has not been recapped.

- The same problem existed for each of these before and after the recaps.

- When swapping out the logic board between SE30s, the image follows the logic board.  For this reason, I have uploaded two pictures of the SE30 screens, labeled Logic Board A and Logic Board B.  These labels are based on the assumption that the problem must be with the logic boards in both cases, since the image follows each logic board when installed in different SE30s.

• Logic Board A has the horizontal lines.
• Logic Board B has the vertical lines.

Weapons:

- With 2 SE30s, it may be easier to diagnose/fix the issue.  If absolutely necessary, I will extract parts from one in order to at least have one operational SE30.

- I have electronics repair tools:  an old oscilloscope, soldering equipment, vmeter, etc.  I have only a beginners knowledge of electronics (1yr hobbyist raspberry pi/arduino/various sensors/garage experiments), but I have a lifelong love for classic Macs!

- The world wide web.

- Hopefully you have some hints based on experience.  I have lost the first battle.  Any advice on how one might win the war?

 

[techknight]

The logic boards are at fault. Those images are generated based on the initial state of the VRAM on power-up. Each brand of VRAM will show a different "init" screen like that. 

If those are the ones from me, they were tested and working before they left. 

So most likely you have bad ROM/RAM simms, or you need to meter your 5V Rail and make sure its not too low. 

 

[360alaska]

A wash might do you good in this case also...

 

[doug.smith]

And....folks....that's how it's done!

I swapped out the ROM simm and one set of RAM and voila, gimme a diskette!  Installed the same ROM simm and RAM to other logic board, and BAM:  2 for 2!  

If the 68k Liberation Army offered medals for service, Techknight, you'd have the Medal of Honor.  Thank you sir!

 

[360alaska]

And....folks....that's how it's done!

I swapped out the ROM simm and one set of RAM and voila, gimme a diskette!  Installed the same ROM simm and RAM to other logic board, and BAM:  2 for 2!  

If the 68k Liberation Army offered medals for service, Techknight, you'd have the Medal of Honor.  Thank you sir!

One of mine had the screen on right after a recap and I removed the ram in Bank B and it did fire up but didn't work for long. I give him a wash and then he did boot but gave me jail bars at which point I had to a jumper wire...

 

[techknight]

Unless another trace is flaky which the odds are pretty good, I already went through those boards and patched them up. 

 

[Elfen]

Interesting, swapping the ROM SIMM and RAM SIMMs fixed it?

Look at the SIMM's edge where the teeth are at. They look dirty or corroded? Wiping it down with a pencil eraser to clean it is a cheap dirty way to clean them. Try them out after cleaning them and post what happens.

 

[techknight]

Well I do know one of the logic boards you had to play with the ROM simm a bit. I think the socket is shot. 

 

[uniserver]

lol... mike... 

acetone and a toothbrush works great to clean simm slots.. 

What happens is flux can get in the simm slots.. for the RAM and ROM with the se30

also cap goo can pool under the ROM simm slot.. and again acetone and a tooth brush helps..

same thing also happens to the pesky IIsi.

 

[falen5]

I have 2 GREAT se30 boards ill swap you for your 2........there pictured a few posts before this one

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mine don't work, they contain bits form 3 other machines and are 100% sure to never work

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ahhhh gowan!!!!!!!!!!

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weh hey!!!!!!!!!!!

 

[macalle69]

Hi Everybody!
i recently buy a Macintosh SE30 , the only "boring" problem are vertical lines on screen , i opened computer and see that it has been recapped, motherboard seems to be in good conditions, i have tried cleaning rom simm and ram : same result .
Installed mother board on other Se30 , same result.
Any suggestion?
Thank you in advance

See pics

 

[falen5]

remove rom, clean using a pencil eraser, try again

try with just 2 roms (think it will boot with just 2...........try with none!!)

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reseat video rom (chip above cpu in picture)

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remove battery and try again

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all else fails get a meter and test continuity on UE8 from pins to via's.

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do the same on UD8 , UF8 and UG8

 

[techknight]

Jail bars = bad UE8.

 

[macalle69]

Thank you TechKnight & falen5  !

 

[uniserver]

well before you remove the UE8 check the lines from UE8 to Vram. here is the schematic.

 

[macalle69]

Thanks Uniserver 

 

[uniserver]

if you find a bad line you can run a wire from that leg of ue8 to the proper leg of the corresponding vram leg.

looks like you have just one bad line. but as techknight said many times the the ue8 could be dead on that line too.

just something to try.  otherwise you can still easily get replacements for ue8, me and techkinght both keep them in stock.

 

[uniserver]

Did you find s dead line from ue8 to vram's?

 

[falen5]

I had similar problem last year, except display was far worse

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found one broken trace on ue8 from pin to via, fixed that, display got better

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then found another bad connection from pin to trace on ud8, display improved , was same as yours.

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lastly found yet another bad connection on ud8, again. fixed that and got a perfect display.

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use meter to check from each pin to the first via and see if you have a good connection

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I had a second good board that helped me perform the checks. Id say you have just 1 bad connection there