Today was fix a classic day. Defender, Asteroids, Sinistar,Gorf

[Level42]

Been working on several cabs of a fellow collector here in Holland today.

First up: DEFENDER. This one was "completely reworked" in the UK and was traded for a (non-working ?) PROTOTYPE Defender !?!?!!? If anyone recognizes himself for this deal, what did you do to get the other one working (messy job, and it's completely dead now, just monitor).

Power supply was replaced by a regular "arcade" switching PSU. Got 4 leds on the ROM board I guess.

ASTEROIDS:
Was dead. Examind the power brick: was messed with a lot. Paper removed from transformer and wires soldered on there. Looks like it may have been wet at one time. Still, it was OK. Turned out the interlock switch of the coindoor was not fully closed when the coindoor was closed. Fixed that, powered up and presto, works

Loud mains hum in the sound.

Marquee was lit very dimly. There were 2 incadescent bulbs in there ! Thought Atari always used fluorescent ? Very smart too, 2 220V bulbs in series connected to the secondary 110V....no wonder it was dim. Owner will replace it with a new TL fixture (on 230V).

Picture would need to be centered a bit, but I didn't want to mess with the centering ring on the neck for a cm. or two.

Picture was looked dreadful, but that was not due to the monitor but some stupid person had put a colored foill in front of the screen with different colors in circles from the center. (Maybe from Gravitar or something like that ??). Removed that, and then it turned out they had tried to "fix" the plexi bezel with what looks like sanding paper. After removing all of that the screen was definitely perfect.

The CRT did have some screenburn off...........(super?) Breakout !!!
So this is definitely not the original tube   You don't see anything (of the burn-in) while playing however.

Cab needs all the usual cap-kits of course. Replaced the Big Blue already.


SINISTAR:  (O no, another Williams, and I've never worked on Williams stuff before.....)

Powers up. Checked all connectors and two connectors on the power board are really hot ! They have very clear burn-marks. I do manage to get some "good" contact and the game starts. Picture OK.
Sound and speech works too.

The game runs in attract mode and says "I hunger for you !" (or something like that) when credited. Can't start a game though. Game runs in attract until a certain frame in the demo, than resets. Credit still registered correctly.=> reconnected the ROM-board connector and pressed down all the (red-label) EPROMs. This fixes the reset problem !

However, we can't input anything. When on the settings screen, the cursor automaticaly goes down all the way. I removed the connector from the 49-way joystick and now the first value increases to the max (= full right I guess).
None of the buttons ever do anything (except coin switches and service switches).

I guess the input board is defective.
Is the 49-way reliable ? There was also a 3 pin connector near the joystick that was not connected, but there seems to be nothing that it could be connected to ?

Will also need to replace the connectors on the PSU of course.

GORF:
Owner thought it was playing blind, but screen did come up very dim. Monitor is G07. Adjusted brightness which improved it. Will need cap-kit and maybe new flyback (was whistling).
There were horizontal lines across the screen (not a monitor problem, maybe a ROM issue/pattern board issue ?
The player's ship seemed to be self-destructing continuously ?

Any tips (esp. on Williams) welcome.

[hummer]

Hi. Total newbie here-got an Asteroids with a loud mains hum-took AR power/audio board out and there is a melted Diode-looks like a IN4001, so off to Radio Shack tomorrow.
If that cures it, I'll let you know, otherewise time to replace the capacitors (including Big Blue!)

[hummer]

OK, the diode made no difference, so replaced all the capacitors on the AR board.
still no difference.
i'veordered  a big blue from ebay, so will fit that when it comes.
if it sdoesn't cure the humming, i'm going to buy a set of amplified pc speakers, powered by a mains supply inside the cabinet, and use the signal straight from the board.
lid closed, who'd know?

[hummer]

Fitted my big blue replacement.
The hum is  certainly much quieter, but I still have to keep it at low volumes or it gets intrusive.

SO I bought some amplified PC speakers at a thrift store for $1, they go in tonight!

[Level42]

Hope it will improve it ! The new big blue didn't do anything about the hum an the asteroids I was working on.