Trimmed the messages a bit... At 1:33 PM +0200 10/13/06, Gooijen, Henk wrote: Henk, I noticed this in your pictures. Interesting. I have the print set here too and I'll look also. While I personally haven't powered the machine up yet, I'm fairly certain it was running just prior to my acquisition from a former DEC FE. [I don't mean to implicate him if indeed the module should be in 1EF as it's possible the machine wasn't working and/or I might have inadvertently moved a few things around.] John

Wow, I'm glad you guys (Don, Henk) caught that before I powered up the system! Now that you point it out, I see it. It's also made clear in the 11/70 maintenance and installation manual. 1EF it is. One less thing to fry. Thanks, John

/ Van: cctalk-bounces at classiccmp.org namens Jay West / Verzonden: vr 13-10-2006 22:53 / Aan: General Discussion: On-Topic and Off-Topic Posts / Onderwerp: 11/34 irks / / Ya know... if you're going to design and manufacture a "modular" power / supply like is in the 11/34A/BA11K, with those nice regulator modules... / wouldn't you think it could be designed so you could pull them out to / replace or add without having to remove the backend of the chassis? That's / just silly. / / Perhaps I'm missing it. It appears that you take off the top cover, undo a / holding screw in the back (one per regulator), and undo the connector for / that regulator underneath. But the two screws underneath and inside? Those / don't seem to be removable without taking off the back end of the chassis. / Icky. GrumbleGrumble... / / Jay Nope, to remove the PSU bricks, you must remove the 3 short screws at both sides. Notice that the metal has a small "triangle" cut out the sheet. Near that is the screw you remove *last*. After removing the other two at both sides and loosening the 3rd screw, you can open up the PSU box a little. With a bit of effort you can disconnect all cables. Make notes! Then unscrew the last one ... Be prepared! The PSU is most of the weight of the whole box ! Now you know why I do fitness 4x a week :-) - Henk. This message and attachment(s) are intended solely for the use of the addressee and may contain information that is privileged, confidential or otherwise exempt from disclosure under applicable law. If you are not the intended recipient or agent thereof responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, please notify the sender immediately by telephone and with a "reply" message. Thank you for your cooperation.

It's not quite as bad... What you do is : Remove top cover, loosen the top screw holding the PSU ('backend of the chassis) on each side, and remove the bottmo 2 screws on each side. Then swing the CPU to the vertical position (That's one reason why the rack slides have a tilt mechanism) and the PSU will swing away from the backplane are. Unplug the 8 pin mate-n-lock, remove the 3 screws and slide the regulator out. The connecotrs are on the front of the regulators themselves, not the connectors on the power distrbution PCB. -tony

I found they got a lot worse in the early 1980s. If your BA11-K is not in a rack, then loosen/take out the screws as above, then tip the CPU box onto one side. You can then ease the PSU away I am sure I've stated ARD's law of DECSA construction before -- 'The lower the importance of a part of a DECSA, the more screws hold it in place'. The PSUs are held in my 2 screws, the fan tray by 4 screws, but the grille over the fan tray is held on by an amazing 28 screws. Removing the backplane from a DECSA is an entertainment. Everything else has to come out first... -tony

On 10/13/2006 at 6:53 PM Roy J. Tellason wrote: sorts It's like everything else nowadays--not made to be serviced at all, just easy to manufacture. The idea being that if you keep your Lumina long enough to have a dead battery, you should have already purchased a new one. Cheers, Chuck

My favourite 2 'easy to work on' items are both video displays -- a Barco colour monitor nad an HP1311 XY vector display. The point being there's an extended card for the plug-in PCBs stored in a spare slot inside. One of my least-favourite machines to work on is the DEC Rainbow. It seems almsot impossible to set that thing up so that you can get to testpoints on the mainboard. I can rememebr having the PSU balanced upside-down alongside the logic board assembly, for example. Half the time it seems things are deliberately difficult to repair. Using heat-stakes in place of screws, putting things in the least accessible place possible, and so on. I am gettign fed up with the number of cars where it's difficult to change the timing (camshaft) belt. I've seen many examples where the belt goes _through_ an engine mounting, meaning you have to support the engine and remove the mounting to change the belt. Or drop the engine a bit to get to the crankshaft bolt, or... -tony

What about those chrysler 2.2/2.5? Do the timing belt on those, it's a SNAP. Did one in my caravan, 2.2 carb to be sure :)) Slugmobile but get job done. Cheers, Wizard

Is decidedly off-topic.

Gooijen, Henk wrote: I don't have my own 11/70 :-( so I can't verify the actual position expected for the M9312 on the cpu side, but the M9312 print set install guide does point out that for an 11/70 application the M9312 would go in slot EF1 of the processor backplane (not 1AB). Not clear how this would apply to the 11/45 backplane, if at all.