Picked up a 1979 Williams Gorgar Pinball Machine in May of 2016
Machine does not boot into game. Tested 5v (4.9) and 12v (11.4). Seems ok. Blanking signal stays low (should go high to run game). Reseated all interconnect cables and the MPU/driver board 40 pin connector. No luck. Powering up the game turns the GI lights on, a slight 'bump' noise from the speaker after a few seconds and that's about it. No lights on the displays and no playfield lights or sounds. Only lights working are GI lights.
What's been done:
6/12/16 Initial light cleaning of playfield with Novus 1/2 and general cabinet vacuum and light cleaning
6/12/16 Ordered Cointaker full Premium LED kit
6/18/16 Ordered new speaker from Pinballpro.com (GLM Enterprises) 8ohm subwoofer/speaker all in one
6/18/16 Ordered cap kit for sound board, springs for ball launch and pop bumpers, bridge rectifiers x2 for backbox, full fuse kit
6/18/16 Installed Rottendog power supply board. All voltages measure fine.
6/18/16 Installed Rottendog MPU/driver board. Game now runs and can be played but no sound at all.
6/18/16 Installed Replaced ALL light bulbs in the backbox with Cointaker Premium LEDs
6/19/16 Installed Pinscore LED displays in the backbox. The old plasma displays were not working. Pinscore displays work perfect!
6/19/16 Noticed some minor sparking from electrical arc on DC connections to the backbox bridge rectifiers. Connections are very corroded and not making good contact.
6/19/16 Measured zero ohms across the speaker terminals so it is blown or very close to blown. New one on order.
6/19/16 Replaced speaker with 8ohm temporary - no sound still
6/19/16 Tested voltages on sound board all good +5, +12, -12. No audio or hiss at max volume. Suspect TDA2002 amp. Will replace with NTE1288 which cross references to TDA2003 which is a drop in replacement for TDA2002.
6/19/16 Verified pin 40 on sound board CPU is high as it should be.
6/19/16 Visual inspection turned up several bulging caps on the sound board. Cap kit on order.
6/19/16 Replaced the TDA2002 on audio board with NTE1288. Also replaced a couple of capacitors. Sound is fixed!
6/21/16 Installed a/c line fuses between the transformer and bridge rectifiers 8A fuses x2 (1 on each bridge rectifier)
6/21/16 Replaced main a/c filter cap with 27k 25v. GI and solenoid circuits.
6/23/16 Replaced remaining sound board capacitors and replaced fuse holders and 4A SB fuses x2
6/24/16 Replaced both backbox bridge rectifiers (35A 400V) 6BR1 and 6BR2 and new spade connectors
6/27/16 Replaced sound rom IC12 with new ROM from thatpinballplace.com (John Wart)
6/27/16 Replaced speaker with one from pinballpro.com. Sounds Awesome!
7/17/16 Replaced loose GI bulb sockets on back box. All solid now.
7/17/16 Installed lift channel for backglass
7/17/16 Installed new cam lock on backbox. Old one had to be drilled out - no key.
9/8/16 Received new back glass from Planetary Pinball Supply. Beautiful!
9/8/16 Ordered new drop target pcb's and molex connectors, headers, and pins for the drop targets.
9/17/16 Rebuilt 'GAR' targets with new pcbs and horseshoe contacts.
11/7/16 Installed rebuilt 'GAR' drop target assembly using Molex connectors vs. the original soldering all wires. GAR targets all work and score as they should and targets now reset once all targets are dropped.
11/12/16 Rebuilt 'GOR' targets with new pcbs and horseshoe contacts.
12/1/16 Installed rebuilt 'GOR' drop target assembly using Molex connects vs. the original soldering all wires. GOR targets all work and score as they should and targets now reset once all targets are dropped.
Game info and initial parts I'm looking to replace:
Backbox bridge rectifiers (x2). One is for the lamp matrix (blue wires), one is for the solenoid matrix (red wires). 35A 400V rectifier w/lugs. DONE
Main A/C filter capacitor - this is for the lamp matrix and solenoid power. It is a 30,000 mfd 25V capacitor. DONE
Replace all fuses
Sound board capacitor kit. Game has no sounds as of 6/19/16. Speaker is blown (0 ohms across terminals) so will install new speaker when part arrives DONE
Sound Rom @IC12 is a 2732. Legs look corroded so may replace it. Update 6/20/16: ordered a new sound ROM from ThatPinballPlace.com (John Wart). DONE
Parts for next Marco Order:
Backglass lift channel part #03-8229-30
Lamp sockets for backglass 2 prong(077-5000-00) and 3 prong (077-5001-00). Order 5 of each. 3 prong were OOS - didn't really need them so all good.
Mini-post - wood screw 2A-3905 (#02-3905) - this goes by the spinner and is currently missing from the playfield
Rubber ring - White 27/64 inch or 7/16 inch OD (#38-2764). Goes on the mini-post above.
Mini-post 8-32 thread (#02-4003)
Nut 8-32 keps (#4408-01128-00). Order 5 of these.
Stop nut - Nylock 8-32 R/B (#240-5102-00). Order 5 of these.
Switch - dual contact (#SW-2010A). $13.95 each.
Drop target stickers for 'GOR' and 'GAR' target banks. 6 total (2 banks of 3).
Drop target springs (x6) Possibly part #10-364 (confirmed per Dok)
Switch - leaf - slingshot normally open. SW-1A-120 (x6)
Machine Screw 5-40 x 5/8 inch p-ph
#4005-01005-10 (x10)
Nut 5-40 esn #4405-01119-00 (x10)
Recommended upgrades:
Add 2 fuses to the a/c lines going into the backbox bridge rectifiers. Use 18 gauge wire. 1/4" hex head screws to mount fuse holders. Fuse holders from radioshack. Put in line on one of the blue wires to 6BR1 (doesn't matter which one) and in line on one of the red wires to 6BR2 (doesn't matter which one). Make solder connections. Install 8A slow blow fuses in both. DONE
Replace the entire power supply board with one from Rottendog, so no need to replace caps and perform recommended upgrades on power supply board. DONE
Test points:
Power Supply Board
Remove all power supply connectors except for J1 and J2 (rectangular connectors on the bottom of board near the right). Black lead on J5 pin 1 (ground), red lead on J5 pin 3. Should see -90 to -105 volts DC. Move red lead to J5 pin 4 and should see +90 to +105 volts DC. This is the high voltage to the LCD displays. Tested OK
With all power supply connectors removed except for J1 and J2, turn game on. Meter black lead on J3 pin 3 (ground), red lead on J3 pin 6 to pin 9. Should see 28-38 volts DC. If missing, fuse is probably blown, connector is bad, or backbox 6BR2 failed. Tested OK
Resource Links:
Order replacement game ROMs and Sound/Speech ROMs here
Drop target horseshoe contacts for drop targets
http://www.johns-arcade.com/#!product-page/c1cs/fe541d01-9487-1880-9dad-44b7f166196c
Replacement PCBs: MPU, driver, power supply, sound and speech boards. Also has interconnect cables, connector sets, CPU and PIA chips, etc.
Marco Specialties - Lots of game specific parts including playfield plastics, pinscore system, etc.
Mark's Guide To Williams System 3-7 Troubleshooting And Repair
Repairing Williams System 3 through 7 Pinball 1977-1984
Drop target wiring diagram - site also has parts and someday may have horseshoe contact replacements using micro switches
Reproduction backglass