Goldstar GDO-101M General Maintenance

GoldStar 3DO GDO-101M

The Goldstar GDO-101M was built in 1994 and 1995, and the parts that wear are the disc drive mechanism, the electrolytic capacitors, the coin cell that keeps the save memory and the switches and connectors. GoldStar published an owner's manual for it but no service manual has surfaced; the measurements below come from a community drawing of the power supply, and the drive work from owners' repair reports.

Safety

The mains lead is fixed and goes straight to the transformer T1. The POWER switch acts only on the low-voltage regulators, so the transformer primary is live whenever the plug is in, with the console switched off. Unplug the console before opening it. The rest of the power board runs from the transformer's 16 V secondary; the fuse F1 (3.15 A, 250 V) is on that side.

The disc drive has a class 1 laser. Do not look into the lens with the drive running.

Disc drive

The drive is a Sanyo mechanism in two parts: an electronics board and a laser board with its sled, joined by a 30-way, 1 mm pitch flexible cable. The same drive is in the Sanyo IMP-21J TRY. To reach it, lift the shield off the top of the drive; the board behind the tray is held by screws.

Cleaning and lubrication

1. Clean the lens with isopropyl alcohol on a cotton bud. A lens that is fogged or scratched has to be replaced with the laser.
2. Clean old grease and dirt from the sled rails and the tray gears, and grease them sparingly with dielectric silicone grease.
3. Check the tray gear train. The shaft in it has tabs on top that break off; once they go the gears misalign and the tray runs slowly or sticks. A printable replacement shaft exists.
4. Check the composite gear between the sled motor's worm and the motor, and the gear in the middle of the sled drive. A drive that grinds and will not move the laser usually has one of these stripped; printed replacements are available for the second.

The flexible cable

The cable between the two drive boards flexes every time the sled moves, and it breaks with age. A damaged cable, like a faulty drive microswitch, gives a console that shows the 3DO logo and then loops on a black screen. The first production run of the GDO-101 had a faulty cable, which GoldStar replaced under warranty. ConsoleMods recommends replacing it with a longer cable than the original: a 30-way, 1 mm pitch, 200 mm flat flexible cable with its contacts on the same side at both ends (Mouser 710-686630200001 is the one it names).

Switches

The drive has a microswitch that the sled presses at its inner stop, which tells the console where the laser is, and two switches that detect the tray open and closed. Clean them if the tray misbehaves; the Troubleshooting Guide covers the symptoms. A faulty microswitch can be dismantled and rebuilt, but ConsoleMods advises fitting a new one.

Laser

The laser is the 10-pin Sanyo SF-C93AQ, also used in the Sega CDX and the Sanyo TRY. A new pickup arrives with a solder bridge across two of its flex contacts to protect it from static; remove the bridge with solder wick before connecting it. With the bridge left in place the laser moves but the disc does not spin.

Save memory and coin cell

Game saves and stored audio CD play programmes are kept in 32 KB of battery-backed SRAM. A coin cell on the main board keeps the SRAM alive; C123 sits beside it. GoldStar does not give the cell type, so read it off the cell before ordering. Removing the cell loses the saves unless a 3 V supply is held on the SRAM while the cell is changed. If the console reports that it cannot save, the memory may be full. GoldStar's manual says to delete items with a memory storage manager tool, which is on some discs.

Check the area round the cell for corrosion. See Battery Explosion, Capacitor or Corrosion Damage.

Capacitors

The 3DO Development Repo lists all of the electrolytic capacitors as a common failure on the GDO-101 and GDO-202. Console5 lists 48 positions across the four boards. The full list and procedure are on the Goldstar GDO-101M Capacitor Replacement Guide; for the warning signs see Capacitor Failure Symptoms.

Power supply checks

Measure at the power board's output connector CON3 with the console switched on. The drawing gives these values:

GDO-101M power supply measurements (6870S-263AA drawing)

Point	Value on the drawing
Transformer secondary, at CON1	About 16 V AC (15.8 V measured)
Reservoir C3 (4700 µF)	+18.0 V
CON3 pins 3 and 4	+11.88 V
CON3 pins 5 and 6	+5.05 V
CON3 pin 7 (CTL)	4.80 V on, 0 V off
Switch node (SW1)	4.93 V on, 0 V off

A replacement supply built around a PicoPSU is sold for the GDO-101M by Will's Console Modifications.

Connectors and switches

• The RF channel switch gets dirty. If the RF picture is poor on both channels, work the switch back and forth.
• The expansion port has been found on one GDO-101 with some of its pins never soldered, which made an optical drive emulator reset the console. Inspect the joints and resolder them if needed.
• Clean the expansion port contacts with isopropyl alcohol or DeoxIT and a toothbrush.

GDO-101 (Korea)

The South Korean GDO-101 is the same machine for the home market. Its rating plate reads AC 220 V, 60 Hz, 15 W, and the caution line says it is for 220 V only. It needs a 220 V supply, or a step-up converter on 110–120 V mains; archive3do suggests the alternative of fitting the supply from a North American console. Its drive, boards and connectors are treated the same way as the GDO-101M's: archive3do reports that the Korean consoles share the hardware revisions of their export counterparts.

Related pages

• Goldstar GDO-101M 3DO
• Goldstar GDO-101M Troubleshooting Guide
• Goldstar GDO-101M Capacitor Replacement Guide
• Goldstar GDO-101M Documentation
• Recommended Tools