Missing main power cord and a few small issues spotted but generally the system is in good shape

BEGINNING ON THE RESTORATION, LOOKING CLOSER AT EVERYTHING

I removed most of the covers and began to inspect more closely to be certain there arent any show stopper kinds of damage before I start spending money on parts and supplies. The SLT cards look pristine, the backplanes and all the signal wires look great. 

I did find some spots with evidence of sustained rodent urination leading to rust and corrosion. The bracket that supports the SMS card connectors where the disk drive power, typewriter power and the console printer signal lines are connected was one such place. I noticed that the contacts for one of the console printer connectors were tarnished due to the contamination. That is repairable.

The power box was already identified, but the usage meter power supply box also shows serious urine induced rusting and warrants internal inspection. We had also spotted the rust inside the disk drive. So far, nothing else has popped up. I will be removing the main power supply (raw DC voltages) and inspect it since it has a metal grill top and therefore the insides could have sustained damage. 

The cover on the top of the machine can be rotated to the right to gain access to the CE switches such as Lamp Test. It is hinged on the right side of the machine and has a support bracket to keep it from torquing sideways as it is moved. That bracket was damaged and disconnected sometime in the past. A part should slide through a channel but it likely became stuck with gummed up lubricants. Applying way too much force causes it to bend and then have to be disconnected. I believe I can reshape and repair it. 

support bracket needing repair

MAIN POWER CORD WAS SLICED OFF AND MISSING

I was surprised to find that the main power cord which would have been plugged into the building power is completely missing. Somebody sliced it clean off at the point where it enters the line filter on its way into the 1130. 

Copper has gotten a bit expensive in recent years, but even with all the power box rewiring and a new 30 amp cable this won't be a deal breaker cost. 

REMOVING DISK DRIVE DUE TO EXTENSIVE RUST/DIRT REMEDIATION

I will completely remove the disk drive and get it onto a workbench as it must get substantial work to remove all the dirt, the seed remnants, the rust and any corrosion caused by animal excretions. I inspected inside the SLT card cage on the disk drive, with no signs of damage from incursions. 

The cards should be held in place onto the backplane by the plastic bar you see across the top. It should snap into the plastic fingers at top and bottom but the plastic has aged and snapped off. This is not unexpected. IBM chose materials for their mainframe products built in the 1960s that all degrade badly with time. The oil and grease turn into sludge or glue. The foam soundproofing either crumbles into a powder or reverts to an oily mass. Plastics loose their plasticizers and break. 

The removal of the drive does give me better access to the power and cabling area deep inside the machine where I am doing rewiring. With all the signal lines for the peripherals passing through that area, a careful look is warranted. 

Beginning the removal of the drive

As I disconnected the disk start switch at the front of the machine, I discovered that the bar on which the switch is mounted was only connected to the 1130 frame with wire lacing cord, not the necessary bolts and nuts. 

A bolt and nut belongs here

A few wires left and I can lift it out onto the bench