Cleaning and restoring your PS/2


Not everything needs to be on-hand.

The oldest PS/2s have hit 33 years... Some were used in clean environments, some in cotton mills, some as industrial controllers.... Some times, all you need to is wipe off the case.. but others were stored in humid environments, and the interior of the case is rusted. Shipping seems to be damaging, busted bezels and bent metal...


Tools:  
3/16 nutdriver [remove 4-40 hex posts, smaller screws]
1/4 nutdriver [larger screws]
Small straight blade screwdriver [floppy service]
Small phillips [0? for floppy service]
Security Torx [T10, IIRC]
Security phillips [#2?]
1/4 wide straight blade screwdriver
Needle nose pliers / tweezers [Major Tom[
Old toothbrush
Dental pick
Vise Grips / Channel Locks [for reforming sheetmetal]
Headlamp / flashlight / trouble lamp
5/32 deep socket [Model M case screws]
Magnifier [goggles, loupe, whatever]

Consumables:  
Soap and water
Baking Soda
Q-Tips
Canned electronics duster [Air Jet is great.. but costly]
Vacuum cleaner [IBM recommends vacuum, not compressed air]
409 spray-on cleaner [handles most grime and markers]
Isopropyl Alcohol [Major Tom]
Evapo-Rust (used liquid is non-toxic) [removes ALL oxidation, including rust and anodizing]
Naval Jelly [used liquid is toxic]
Goo Gone (not universally effective) [stickers]
DeOxit contact cleaner
Brillo pads [Model 50 / 70 / 90 planar power contact cleaning]
Rust-Oleum Professional Galvanizing Compound Spray
Bank note / bond paper [buffing edge contacts]
Paper towels / work towels
Pen / Pencil / Paper [documenting chipsets or assembly details]
Plastic Surgery 

Equipment: 
DMM [continuity beep is a plus]
AVO [Amp / Volt / Ohm [WBST]
POST-Probe
Wrap plugs [serial, parallel, network]
ShopVac [Jim Shorney]
Air Compressor (beware of too much pressure!) [Major Tom]

Brighten Discolored Plastic Components  
Retro-Brite is a significant procedure that you can use on clone component plastics that have discolored over the years. IIRC, most IBM plastics aren't affected as much, due to limited levels of bromides. Once you Retro-Brite, the remaining Bromide compounds will still travel to the surface, and eventually discolor plastics. The presence of UV hastens the discoloration.

Detect Flat Pack Cold Solder Joint Leads  
Dental picks can be used to "sweep" the leads of a flat pack. As long as the leads are connected with solder, the pitch stays the same. Loose leads have a higher pitch [ting]. [Jose Deras]

Remove Surface or Deep Rust  
Evapo-Rust is quite useful in removing surface rust -AND- deep rust. Rust inhibits dependable contact between any EMI shields and the steel of the computer case. The liquid form is the BOMB, but the jelly form has significant consistency problems. Naval Jelly might be better on vertical surfaces.

Re-Galvanize Damaged Case Sheetmetal  
Rust-Oleum  Professional Galvanizing Compound Spray 
For those of us that have faced a rusty steel frame while restoring our PS/2s, using Evapo-Rust or other rust remover, will remove the rust and leave the base metal exposed.

Rust-Oleum  Professional Galvanizing Compound Spray 
Technical Data

SKU     Color        UPC
7584838 Bright Gray 020066758486
7585838 Cold Gray   020066758585 [Cold Grey looks to be a closer match.]

"Instantly galvanize metal surfaces to protect them from corrosion with Rust-Oleum Professional Galvanizing Compound Spray. This 93% pure zinc coating applies a galvanized film with cathodic protection, which resists rusts, scratches and chips."

ButINeededThatName wrote
    I used Rust-Oleum "Professional" Cold-Galvanizing Spray. The coating ends up being a shade or two darker and not as "shiny", but when you redo the whole inside of a case it ends up looking pretty good and "like it belongs".

Clean Adapter Edge Contacts or Keyboard Mylar Tape Connector Contacts     
Bank note / bond paper is used to buff the MCA adapter's edge contacts. It makes the gold shine -AND- it does not leave any crumbles -AND- it isn't an aggressive abrasive. When you work on a Model M keyboard, the mylar sheet has metalized traces that slip into those clip connectors. If the contacts look like tarnished silver, use a folded bill to buff then to a light silver color.

Cleaning MCA Slot Spring Fingers
WBST said: install and remove an adapter from the same socket a few times (max. 3 should do it) to perform mutual oxidation / contamination removal. Chemicals [like DeOxit] are a last resort in my opinion, minor abrasion should clean off any slight oxidation or thin film deposits, say with a toothpick?

Remove Green "Spooge" From Leaky Battery 
   Make up a thin paste of baking soda and water. Apply with Q-Tip or toothbrush, swabbing or brushing residue away. Rinse with water. Let dry.

Remove Serial / Parallel / Video Port Hex Posts
  You will need a 3/16 thin wall nutdriver to fit over the 4-40 threaded post -AND- be thin enough so as to clear the shield.

Clean Floppy / Tape Heads / Keycaps / Cases / Plastic Parts / Planars / Adapters    
Isopropyl Alcohol (Denatured as well) on Q-Tips can remove contaminants on the heads or capstan wheels, metal parts, components on PCBs or adapters..

Repair Cracked Non-Stressed Plastic  
In many instances, cracked plastic in NON-STRESSED areas can be successfully repaired with "Plastic Surgery" adhesive. IF you try to repair threaded plastic screw posts or bendable parts, the repair will crack again...

Open Power Supply Units  [Screws, Rivets, Tamper-Proof]
PSUs can attract dust bunnies and oily dust [among other things]. To open most PSU cases, you will need Phillips or Torx security bits with the little post in the center. A few units [P70 and P75] are riveted closed, requiring you to drill them out [use a chisel or screwdriver to help prevent the rivet from spinning while you drill it out] and replace the removed rivets with metal screws [careful of the screw's length!]. Model 60, 65, and 80 units may use an odd one-way tamper-proof screw, try a par of Vice-Grips or similar.

Blow Out PSUs, MCA Slots, Around Components  
Random errors and thermal shutdowns can be caused by contaminants inside MCA slots, PSUs, and dust/grime that has settled on/under components. Thermally stressed electronic components [build-up of dust/grime over cooling fins / blockage of air flow] will have a shorter life-span.

Cans of computer duster will handle light dust, but the heavier layers, dust bunniez, and deeply set components may benefit from the judicious use of an air compressor set to a low pressure [10psi?]. High pressure air can bend thin sheetmetal, damage floppy head mechanisms, and/or lift components off the PCB.

Close Model 85 and Model 95 Side Wall  
The 95 style case is renown for durability and... heft. You tend to use two hands, but could really use three... So... you have run the cables so they won't be crimped by the closing side wall. You carefully lift up the side wall with two hands, lining up the lip on the rear so that it fits into the case. At the same time, you keep the upper "lip" of the side wall over the slightly rebated upper edge of the case.

Now... this is where proper form beats out speed. Push the side wall to the rear so it's rear "lip" fits into the case. Place your LEFT hand on the top-left of the case, opposite the side wall. With your RIGHT hand, grasp the side wall and while keeping a rearward pressure, rotate the side wall so it mates with the case. Rearward pressure keeps the side wall in the proper position, front to back. If the side wall is allowed to close without being pushed to the rear, the front edge of the side wall will prevent the front bezel from being able to hook in and swing down.

Do NOT place your LEFT hand on the top-right side of the case next to the side wall... If your fingers stray into the space between the side wall and the top-right of the case, you will get a pinch injury. You CAN loose blood.

Insert Blank MCA Slot Cover 
These dapper devils can slice you open quite easily. Think about it, a very thin stamped metal part that requires a bit of force to install. If you run with scissors, your blood will pave the way to the future....

Look at the MCA slot cover from the front. At the bottom is a "U" that slides over the shaft of the thumbscrew. At the top is a "T" with very short arms. Now the simple way is to stuff the slot cover down into the aluminum slot guide. But.. that isn't the most reliable method...

The way I finally adopted is to use two hands, one inside the case and the other outside the case. Using your thumb and index finger, slide the cover down into the guide. Now re-position your fingers to control the slot cover. Using your index finger and middle finger on the inside, and your index finger and middle finger on the outside, slide the cover into the guide. The pressure on BOTH sides allows you to reliably fit the "U" over the thumbscrew shaft.

If the bottom of the cover sticks out too far to the outside, it might allow the "U" to straddle the thumbscrew, and if you have the newer systems with anodized aluminum thumbscrew, you will scrape a nice shiny cut around the softer aluminum as you try [and fail!] to tighten the thumbscrew down onto the slot cover. Looks bad.

Remember that short "T" at the top? Now we are entering the advanced geek territory. The aluminum slot guides are narrowly placed to each other, such that the short arms of the "T" can be above or below each other, preventing the top cross arms from being fully seated.

Note that the recess at the top of the aluminum slot guide [for the cross arms] is quite a bit wider, front to back, than needed to simply hold the cross arms. That is so you can place one slot cover's cross arms to the front of the recess, and place the other towards the rear of the recess.

Close Model 85 and Model 95 PSU 
After you finish changing your memory, you will need to re-seat the swinging PSU. There are a few techniques to prevent damage and frustration...

Push the PSU towards the REAR of the system. The PSU rides on two pins on the bottom outside edge that point to the front. If it has worked it's way forward, simmply rotating it up won't result in successful mating of the PSU plug and the planar receptacle. Also note there is an angled guide at the bottom front, outer edge of the case, that the PSU is guided by when rotating it back into position.

Carefully route SCSI cables out of the way. Some cable routing for SCSI cables lets the cable get in the way of the PSU when it is swung back up. Fast/Wide cables with flat n twist cables require more care, due to the small easily crushed cables... Cable sheathing, either techflex or wire loom, keeps most damage from happening.

Push any CDROMs forward so their cables are not in the arc made by the swinging PSU. I call this a guillotine...

Use one hand to push the HD power cables to the front, out of the arc of the swinging PSU.

Now comes a common problem. When re-seating the PSU so it mates with the planar, you need to press the top of the PSU so it mates with the planar receptacle. While holding the PSU in place, push down the blue knob [spring pressure] and screw it in until it seats. Do not use more than finger pressure since the T knob depends on an e-clip on the shaft to hold it together. Screw it down until firmly seated.

If you use your full hand to tighten the T knob there is a decent chance that the e-clip will pop off the shaft and fall down into the system [bad enough] or on earlier models, possibly fall INTO the PSU....