Recapped SE/30 working fine...

[Juror22]

I want to thank everyone on this board for their posts - I lucked into a free SE/30 and a Quadra 900 (one of my co-workers was moving and either gave away or sold a great deal of items, including these two). The SE/30 worked okay, but immediately started to show bad-cap issues. I washed the MB and that improved it for a time, but then I had increased issues and the last time that I cleaned the board around the caps, it would not boot fully anymore (a shame since I had just cleaned/re-greased my floppy drive). I did not feel that I had sufficient skill to re-cap the board, but since then I have been getting some additional soldering practice fixing other computers and I felt that I had enough experience to re-cap the board.

SUCCESS!

The unsoldering was uneventful using the two gun method, except for two pads that lifted slightly at the tip. The caps of course came from Trag (I had ordered them a while back) The soldering was not uniformly picture perfect, but wasn't ugly either and it restored the computer to full working condition. RIght now it is running 7.0.1 with 32MB.

I have a second SE/30 (got it about half a year ago at a nearby town for $20 that has early symptoms (no sound) and some boot issues, so with this success behind me, I will definitely give the second one the same treatment. Without the collected expertise of this forum, I would never have been able to bring it back to life...thanks again!

- Juror22

 

[zuiko21]

Congratulations!

Now, I have to get the guts for replacing the SCSI chip in one of my SE/30s... :-/

 

[phreakout]

zuiko21,

Don't do it, unless you have a hot air rework solder/desolder workstation. Using the 2 pencil soldering iron technique or alike will destroy the pads and make for an unpleasant time trying to swap out the parts. I'm trying to get one completed for a member here and I ended up using enamel coated wires to go between the chip and each of the chip's solder pads. Ugh!

Use the rework station along with solder paste is the best I can recommend.

73s de Phreakout. :rambo:

 

[trag]

Not for the faint of heart, but in order to desolder surface mount integrated circuits (as opposed to caps or resistors)...

Examine the area around the target component. Identify any components which might come loose if their solder melts, or which might be damaged by excessive heat. Cover these in modeling clay (the dry stuff that stays soft forever).

Liberally coat the pins of the target chip with liquid solder flux. This helps the solder to melt by preventing oxidation of the solder.

Apply heat from a heat gun to the target chip. Using a pointy implement such as a dental pick, poke at the solder to see if it is softening. Move the heat gun in a circular motion to help with even heating.

On my Milwaukee heat gun, which is continuously adjustable (as opposed to just one or two heat settings) I find a setting of about 8 (~800F) will heat a chip and board enough to melt solder in approximately two minutes. Yes, I sat there and timed this several times. A measure of how often I hacked the UltraTek-66 into a VST Ultra66 way back when.

Once the solder is melting, check the joints to be sure that you don't have any cool ones. Gently pry under the chip with the pointy implement, but do not exert any force to speak of. Certainly, do not lift the board by lifting on the chip.

When the chip comes loose, you are done.

This method is also useful for removing soldered down DIP packages without damage.

After things cool a bit, conduct any needed clean up. Use desolder braid on the circuit board's pads to remove the remaining solder. Clean the board to get rid of flux residue. Remove all the modeling clay. Modeling clay close to the heat will probably be crunchy.

 

[zuiko21]

Many thanks for all of your advice!

Besides the 53C80 replacement, I have in mind several (read: too many ) projects that would definitely benefit from SMD technology, thus it's worth investing in a heat gun and then some experience...

 

[zuiko21]

An update... since I had the SE/30 taken apart while researching for another project, I decided to check the SCSI chip connections according to

the drawing I made -- this is my SCSI-less SE/30, and I want to get it in full working order, as you may deduct from my previous posts.

Guess what? The already suspicious DB2 line was the only broken connection! So maybe the 53C80 is not dead...

Then I decided to hook up a CD300e drive externally, while making a jumper between the DB2 line on the (now empty) internal SCSI connector and the relevant pin on the 53C80. Thanks to a garden variety ATX extension cable (with the rightmost 6 pins unused), servicing the SE/30 becomes unbelievably comfortable, why didn't I think about that before? :'( And it makes holding the jumper by hand, at least, feasible for a quick test.

Can you imagine my expression of joy when I saw the CD's LED flashing (loading the driver), then the Happy Mac, then the Welcome to Macintosh screen? 8-o It didn't boot all the way because the bootable CD at hand was for a Performa 5260, thus incompatible with the SE/30 but what the heck! SCSI is working!



I'm afraid the SE/30's board is multi-layer, and trying to find any flaw seems very difficult... but I can always place a permanent jumper on it. In the meanwhile, I've been advised to put some heat with the iron on the PB2 solder point of the internal SCSI connector, just in case it reflows properly thru all the layers. The connection between the internal and external ports has been checked perfect, BTW.

;D ;D ;D

 

[Byrd]

Thanks to a garden variety ATX extension cable (with the rightmost 6 pins unused), servicing the SE/30 becomes unbelievably comfortable, why didn't I think about that before?

You sir are a legend for thinking of this! The amount of times I've pulled apart a compact Mac for testing, then snapped it all back together scraping and cutting my fingers in the process ... often leading to frustration and packing it all up for another day. I have one of those very ATX extension cables in my box 'o goods with a purpose now.

Good work!

JB

 

[Juror22]

The ATX extension cable idea is brilliant...I have used additional SCSI and power cables for using multiple drives while working on an opened up compact mac, but I never thought to extend the MB cable - awesome! I'm also glad that you were able to determine the issue with your SCSI connections.

Thanks to all for the additional discussion on how to best deal with different kinds of connection disassembly and fixes.

I have recapped my 2nd SE/30 and it works perfectly, except that the sound was not restored. It acts the same as before, crackling (when it should be sounding the startup bong) and there is no other sound. I am going to try hooking up something to the external speaker connector and see if that works.

I also noticed (it may have done this before) that bringing up the sound control panel and setting a different volume or attempting to change the sound to a different one, locks the computer (it is running 7.0). I will do a little more investigation and hopefully get this one back to 100% running condition (although it is nice to have it booting and running normally, even without the sound).