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SE/30 where to start on Dead Screen

Bolle

Well-known member
You are missing VSYNC most probably caused by a bad counter at UF8.

UE8 is likely fine on your board.

 

techknight

Well-known member
that line is also very dim. should be much brighter than that unless you turned the brightness down, so id look at UE8 too. 

 

cannfoddr

Well-known member
I took a look at the board today and reflowed the solder on UF8 and UE8.  Still no joy!

I am waiting for a delivery from Mouser with replacement UE8s and UF8s so when that arrives I will swap out UF8 and see if that helps.

 

cannfoddr

Well-known member
You are missing VSYNC most probably caused by a bad counter at UF8.

UE8 is likely fine on your board.


So I am looking at the schematics.  UF8 looks like it feeds into UG6 pins 2-8 and the VSYNC comes out of UG6 pin 14 which then connects to the PIN 11 on the Logic Board socket:

So I can check continuity between the UF8 and UG6 connections and continuity between UG6 pin 14 and Pin 11 on the socket.

I don't have a scope (yet) - I guess if I did I could power the board and look at the signals on these lines.

Assuming I can prove continuity I guess my next best step is to replace UF8 or am I better just going there first? 

 

cannfoddr

Well-known member
So I have some progress to report.  I checked all the continuity between UF8 -> UGC -> HSYNC Pin on the main board (Pin 11) and there is continuity everywhere there should be.

So I went ahead and replaced UF8 and I now have VSYNC.  The picture fills the screen but is garbage:
after_uf8.jpg
 

The machine still appears to startup, I get a chime and the display comes on but it distorted.

So I then decided to go ahead and replace UE8.  Again the machine boots and I now get a different pattern:

after_uf8_ue8.jpg

Startup is pretty much the same as before:


View attachment startup_vid_after_uf8_ue8.mov





I am not entirely sure where to go next.

  • I'll do some googling and hit the bibles and see if anything matches
  • I'll do some continuity tests around UE8 and see if anything is missing
  • I suspect the next step you guys will suggest in getting it running on a bench and putting a scope on it - I now have access to a scope but have little idea of how and what to probe at this stage (I also don't have my extension logic board cable yet.



Any help you guys can provide would be greatly appreciated.

 
Last edited by a moderator:

SuperSVGA

Well-known member
All the times I've encountered that it's usually something RAM related, but I suppose the causes could vary.

http://bylenga.ddns.net/SE30 repair.html#SimasiMac

First of all, please try solutions (1), (2) and (3). It is easy.
(1) Check and clean connections between SIMMs (ROM-SIMM) and SIMM (ROM-SIMM) slots, and restart.
(2) Remove PDS card(s) such as an accelerator card if installed, and restart.
(3) Check the battery. Replace it with a new one if voltage is low, and restart.

If nothing above works, try solutions (4), (5) or (6) AT YOUR OWN RISK. You NEED soldering and desoldering skill.

(4) Replace electrolytic capacitors C6 (1µF 50V) and C7 (47µF 16V) on the logic board with new ones. Surface mount chip type capacitors are soldered on the original logic board. But you can use miniature radial lead type capacitors instead.
Anyway, be carefull about desoldering and soldering procedures not to break circuit patterns on the board. Make sure the polarity of electrolytic capacitors before soldering.
If you find liquid leak or corrosion of other capacitors, it is a good idea to replace them or all electrolytic capacitors with new ones. Macintosh SE/30 was introduced in 1989 and discotinued in 1991. Electrolytic capacitors have been degraded after years.

(5) If solution (4) doesn't work, pull up the sound IC chip (UB11). You can see letters "SONY 0F09G 3430045B APPLE85" or "SONY 9A04 3430045B APPLE85" printed on the chip. To pull up the IC chip, connect pin 7 to pin 15 of the chip with a 1 kilo ohm resistor.

(6) If solution (5) doesn't work either, replace the network filter RP2 (Bourns 4120R-601-250/201).
Also see 9. Bright Monitor with neither Arrow Pointer nor Startup
 


Also, are those thin bright diagonal lines visible or is that just from the camera? I swear I've seen that somewhere before too.

 

cannfoddr

Well-known member
The diagonals are camera artefacts from my iPhone - the screen is just parallel lines in real life.

Board has been fully recapped and cleaned thoroughly in IPA and dried.

I have a Rominator that I can try and some new 16MB ram sticks.

I have another SE/30 that runs fine without battery - I am not sure that is a requirement to boot.

No PDS cards.

I'll go and try the BMOW rominator and some 16MB ram.

Thanks 

 

SuperSVGA

Well-known member
Yeah it should be fine without the battery, although I've never tested what effect a low or bad battery has on the system.

I would test with only Bank A populated if you haven't already, just to rule out any other problems.

If swapping those out doesn't make any difference you might need to check traces between ram and multiplexers, possibly replacing the multiplexers (typically UI2,3,4,UJ2,3,4 IIRC). Of course I could be on the wrong track here, but that's just my guess.

Now I'm having flashbacks to the SE/30 I had to hot glue all the ram in because the clips broke...

 

cannfoddr

Well-known member
I am being ultra careful with the clips, this board has an odd mix of plastic and metal clips on the sim slots.

I don't think its the Semisamac (??) problem here.  I have tried all combinations of ram and rom I can thing of and always get the same issue.  The interesting thing is as a final test I reconnected the hard drive and powered up.  You can hear the OS loading from the hard disk (I have a video that I will add).  

I am still thinking some kind of logo board video problem.  The first screenshot after UF8 replacement is almost exactly the same as another I saw on another post advising that UE8 needed replacing and certainly replacing UE8 got me to the second screenshot where I am now with my horizontal stripes.

I done as through a continuity test as I can on UE8 UF8 and some of the adjoining video chips UA8-UD8(??) everything seems to be connected according to the schematics - I haven't done everything.

I've reflowed the solder to that entire line of video chips with lots of flux in an attempt to clean things up.

I have packed up for the day now and will continue to do more reading and hope someone comes here with some more ideas.

 

Raster30

Member
battery is not a requirement, I had no battery in mine for a very long time without issue. if you have a spare working se/30 why not swap some parts to isolate the issue. Like take the known working motherboard and bring it over to the non working chassis. this would allow you to isolate the issue down to a component issue on the motherboard or analog board.

 

cannfoddr

Well-known member
battery is not a requirement, I had no battery in mine for a very long time without issue. if you have a spare working se/30 why not swap some parts to isolate the issue. Like take the known working motherboard and bring it over to the non working chassis. this would allow you to isolate the issue down to a component issue on the motherboard or analog board.


Raster I have done all of that - see earlier in this thread, its definitely Logic Board.  The problem moves with the board and the 'good' board works in the 'bad' boards chassis.  Good board with boot either chassis hard disk.  I have swapped ram and rom around the two boards and even used s 3rd SE 800K board I have.  Its just the one SE/30 board that has the video problem.

Plan of record for now, I think:

  1. Build my best possible SE/30 out of the bits that I have:


    • Recap Analog Board
    • Recap Sony Power Supply
    • Find best Floppy
    • Rominator
    • Best HDD of the 2 (fix/fit led)
    • Rebuild OS - HDD/RAScsi
    • Get Ethernet card working/RAScsi Ethernet
    • To Retrobrite or not????
  2. Hope like hell somebody comes up with some suggestions/offers to take a look at the 'bad' board in the meantime
  3. Build new extended power cable so I can run 'bad' board on the bench


    • Hook up oscilloscope and see if I can figure out any missing video signals from schematics (very long shot)
  4. Hunt around for another SE/30 board and use the 'bad' board for spares!!! (last resort)




 
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