Breathing
Member
Hi all,
Several weeks ago I bought on eBay a Mac SE/30 Showing SimaSimac signs... I know it's not wise to buy an known not working system but I can't find one of these SE/30 easily where I leave (Switzerland). Working system that can be find on eBay are just too expensive.
So I did roll the dice and hopped for the best...
The exterior of the machine was in a bad condition, but luckily inside the battery did not exploded (This was my main concern). Sure the motherboard was full of dust, but beside being a bit dirty it was looking fine.
Of course as you would expect all the capacitor did leaked, so I first cleaned the board
Unfortunately the Mac did boot with the Chime of Death (normal speed not slow) and the SimaSimac pattern.
There could still be several issue that need to be checked but since I don’t own a second SE/30 I won’t be able to swap the ROM Video or the PAL IC.
Since I do own a Macintosh SE a Macintosh IIx and IIfx. I would probably be able to do the following:
In the mean time I have several question for you guys:
Clearly I did not yet gone thru all trouble shooting step, but I hope I won’t have to replace SMD IC or VRAM since I don’t know where to source them thus this post to get other point of view and ideas to help me trouble shoot this.
Many thaks for you help!
Several weeks ago I bought on eBay a Mac SE/30 Showing SimaSimac signs... I know it's not wise to buy an known not working system but I can't find one of these SE/30 easily where I leave (Switzerland). Working system that can be find on eBay are just too expensive.
So I did roll the dice and hopped for the best...
The exterior of the machine was in a bad condition, but luckily inside the battery did not exploded (This was my main concern). Sure the motherboard was full of dust, but beside being a bit dirty it was looking fine.
Of course as you would expect all the capacitor did leaked, so I first cleaned the board
- Removed all the electrolytic capacitor
- Clean the motherboard again.
- Finally I replaced the original capacitor with tantalum one (Expect for the axial capacitor and C6 since I couldn’t find tantalum capacitor that can be de-rated and would still fit the original footprint).
- I tested the connection from the new capacitor to make sure they made good contact and none did a shortcut on other traces.
- The ROM-SIMM the video ROM the CPU and all socketed IC where reseated
- 4 RAM Module where added
- A new Lithium battery for the PRAM has been put in place
- Bourns Filters where tested OK
(Without the capacitors)
(With the new capacitors)
Unfortunately the Mac did boot with the Chime of Death (normal speed not slow) and the SimaSimac pattern.
There could still be several issue that need to be checked but since I don’t own a second SE/30 I won’t be able to swap the ROM Video or the PAL IC.
Since I do own a Macintosh SE a Macintosh IIx and IIfx. I would probably be able to do the following:
- Test the Analogue board/Power supply by usiung the one from the SE (But I seriously doubt this could be the problem)
- Swap the 68030 CPU from the IIfx with this Mac SE/30
- Check each connection from the ROM Simm to the CPU, same for the RAM and the Mux.
- Use the ROM SIMM from the IIfx on the Mac SE/30... is this possible?
In the mean time I have several question for you guys:
- On the board I can see that the Audio IC from Sony have corroded legs, but since I do hear the chime of death could I consider the audio part to be fine?
- I read that to clear the SimaSimac issue one could “pull” the audio IC by adding a 1k resistor between pin 7 and 15… but since my audio works is this still relevant?
- How one would trouble shoot the VRAM?
Clearly I did not yet gone thru all trouble shooting step, but I hope I won’t have to replace SMD IC or VRAM since I don’t know where to source them thus this post to get other point of view and ideas to help me trouble shoot this.
Many thaks for you help!
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