Tuesday, September 14, 2021

Magnetic pickup cable repaired and connected, beginning reassembly of x235 server for P390 system

 FINISHED CABLE SWAP FOR MAGNETIC PICKUP USING NEW PIN

The replacement pin for the Amphenol connector arrived yesterday. These cost almost $3 per pin, an indication that they are fairly uncommon now. I prepared the shielding, crimped the pin onto the end and inserted it into the connector.

New cable inserted in connector for Clock card

The connector was then reinstalled in the card cage and aligned for easy insertion of the clock card PCB that fits in slot 1. All that remains is to adjust the magnetic pickup for its target spacing from the teeth on the timing wheel. It needs to be .007" within a tolerance of plus or minus .001 inch. 

I ordered feeler gauges but as I drove home from the workshop I remembered that an IBM punched card is exactly the right thickness - .007" - and therefore I can do an initial setup even before the gauges arrive. 

WRESTLING STRAIGHTENED PCI SLOT METALWORK INTO P390 CHASSIS

I used screws and nuts through some of the rivet holes in order to anchor the rear of the server together now that I had restored it to nearly its original shape. I feel good about the result - it will definitely support the PCI cards properly. 

PCI card holder to fan holder connection

Right side of chassis to PCI card holder

Fan holder to side plate fasteners

BEGAN REASSEMBLY OF THE ESERVER X SERIES 235 OF THE P390

I am working in reverse order from the way I disassembled the server to remove and repair the bent sheet metal. First step was to install the motherboard in place. That fit nicely with all the I/O connectors in the proper position at the rear.

Motherboard (planar) back in the chassis

Next step was to add the conductive metal shield and the card holder plastic pieces. These rotate down and lock over the end of the PCI cards to keep them anchored in place. A long rod is pushed through the four plastic card holders and threaded through holes in the metal section I repaired. 

Here is where I am facing the first consequence of all the bending and distorting that the part went through. Three of the four plastic card holders fit right into place and can be secured by the rod, but the last one, which is the first and most critical, doesn't fit in its area well. It is very difficult to get the rod to pass through the holder and into the hole in the metal plate. I will have to continue to finesse this on the next visit. 

Plastic holder cocked sideways, rod not fitting into metal support

1 comment:

  1. LOL! I remember punched cards as being .0065" but I think you'll be fine with that. :-) I've seen them used as shims and well oil soaked but still quite functional.

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