PCB Repair Logs Gallag
Gallag (Galaga Bootleg)
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| PCB Image | Gallag PCB |
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Repairer: Arcade King
Forum Thread: Gallag (Galaga Bootleg) PCB Repair
Love these boards to bits I've had 3 of them plus a alt board which I will post here I got off a mate. They are quite popular because they have no custom chips, easy to reprogramed to the NAMCO or Midway set and are well made. Only down side is they use common TTL chips to replace the custom ones of the original which makes them a BIG 2 layer board.
I'll split the CPU and Video boards in separate posts
Gallag CPU PCB
This is the one I bought from E-bay it was listed as:
QUOTE: "this galaga board is untested. I doubt very much it will work. I have had it in storage for a while so its a 99% it will not work otherwise i would have used it long ago. I dont have the time in the day to be bother to check to see which layer is good and which one is bad. This board is probably best left for parts to get another galaga working. Happy bidding people."
Well he was honest.
Even in the picture in the listing I could see the CPU sync bus controller was tuned around the wrong way and sure enough when I got the board it was and all IC's on it had been completely fried.
This board was a mess, when I first tried to fire it up nothing came up. I felt the top of the IC's and 2 were VERY hot so I quickly turned it off.
Going over the board I looked for anything that could cause a short so use my multimeter and did a continuity between the ground and +5 volt and there was a short to be sure.
The best and easiest way to locate all the effected chips was to one end of the multimeter on the +5 volt and test each pin on every IC. When I found one I would then switch to the ground finger on the pcbs edge connector to make sure there was a short.
I found 16 IC's which follows:
74ls244 @ C10, H3, K3
74ls374 @ D10, E10, F10
74ls373 @ H2, K2
74ls138 @ A1
74ls158 @ L2
74ls259 @ N3
74ls368 @ P5
74ls107 @ N5
74ls28 @ N6
74ls367@ B1,C1
There were other IC's that appeared to be shorted but some of their pins were grounded already so I left them for now.
Using my little Ms Pacman board I tested the Z80's and rams. 2 Z80s were bad but the rams were all ok even the 7489's. 3 roms were bad @ K4, J4 and E5.
Ok after many hours I replaced all the bad IC's and even had to pinch a few rare ones like the 74ls28 and stripped a stuffed pac board for the others IE 74ls259, 74ls368.
Problem: Turned her on and she was alive with zeros all over the screen.
Fix: 74ls367-can't remember which one.
Problem: Game would boot up and hang on RAM OK. A common fault with these boards. If you turn voltage right up board would run, turning it down again would stop on RAM OK.
Fix: This is where a Scope would have come in handy. Problem was another 74ls367 considering most of these chips were already in sockets towards the top I replaced them all to be safe.
Board works perfect!
Galaga (Code named Spike)
Pic 2 Added some other amusing pics from the guy I bought this from who got it from a well known tech , those who know the history of this board will know what im on about
Chips found faulty via testing on working board were. 2 CPUs one of which had red dot on it and both the Tri State Proms.
Problem: Dead board....really really DEAD!
Fix: bad 74ls161@7L and 7M Took ages to find but a 74ls00@N7 got the board firing up. stuck output pins 8 and 13.
Bad chips found after board fired up.
74ls32@A4 output stuck low pin 13
Problem: Board boots up then hangs on RAM OK
Fix: common fault with these Gallags, bad 74ls367@H1
Problem: Board boots up gets to the Ram ok, Rom ok, upright etc screen then resets.
Fix: Seems to be another common fault on these boards.
74ls244 @ C10
74ls374 @ D10, E10, F10
Problem: Hard one to find this. Board boots up then hangs at the ram ok rom ok screen and wont advance to the cross hatch.
Fix: Bad 74ls138@J7 all the outputs at pins 1 through to 8 were High with no data flowing.
Syncbus controller had been put in the wrong way and as a result all chips except a 74ls02 were fried.
Forgot to mention I knew the sync bus controller was stuffed and was using my pacman one to fix teh board. Left it last to fix.
Board is now fixed other than need to replace a few bad sockets. Need the two missing Tri State proms(empty sockets) which have to do with sound. I know the sound work as I used proms off a working board to test it.
Notes:
You can use a Sync bus controller off pacman on these boards.
Good thing about these is there no wire that has to be connected to the board. The wire that is connected to the board from the regular Syncbus controller connects to a 74ls00 @ A2 pin 2.
I find its a good idea to shorten the pins on the syncbus controller to make it sit just above the roms. Makes everything nice,compact and neat.
Gallag - Galaga Bootleg
CPU Board
Name CKSM Type Loc Label Notes
2732-G1.4B DC00 2732 4B G1
2732-G2.4C 5900 2732 4C G2 Gallag name
2732-G3.4CG 5B00 2732 4C G2G Galaga name
2732-G3.4D 0E00 2732 4D G3
2732-G4.4E 5200 2732 4E G4
2732-G5.4J B2FF 2732 4J G5 Standard Fire
2732-G5.4JF B7FF 2732 4J G5F Rapid Fire chip
2732-G6.5E D121 2732 5E G6 Starfield ROM
2732-G7.4K 66FF 2732 4K G7
82S129-2.5M 0715 82S129 5M 2 Sound
82S129-3.1L 074C 82S129 1L 3
Video Board
Name CKSM Type Loc Label Notes
2732-G9.5R D60A 2732 5R G9
2732-G10.7A B18E 2732 7A G10
2732-G11.6A 6627 2732 6A G11
82S123-1.9P 0E48 82S123 9P 1
82S129-4.4P 0241 82S129 4P 4
82S129-5.1D 01C0 82S129 1D 5
There is a small daugher card in a 28 pin socket at 4F.
Gallag 2114 RAM error codes
Video Board
6F RAM 2L
6H RAM 2H
6J RAM 4L
6K RAM 4H
6L RAM 3L
6M RAM 3H
CPU Board
5D the game displays "RAM OK" but you can't exit the setup page
5C the game displays "RAM OK", then reboot forever
Info taken from various sources from the net can't remember about the rom info, but the ram errors and pinouts were taken from Mikes Arcade
Blue Video Board Spike
Picture 1 white dots indicate IC's replaced interestingly enough some of which had red dots
Problem: Video board was DEAD no sync nothing!
FIX: I Found that EVERY single 74ls74 was bad except one at C4 Every 74ls00 was bad also replacing them gave life to the board.
Problem: Flashing characters at bottom of screen.
Fix: IC at A9 on video board 74ls365. Pin 8(output) was High.
This also fixed some garbled characters but they were all wrong!
Problem: Garbled characters they were all lines except the ones that the above fixed however they were all still wrong. Text on the screen was fine.
Fix: Roms 10 and 11 were swapped around.
11=A6
10=A7
Think I stuffed this one up meh live and learn.
Problem: Missing Starfield, At first the starfield became erratic and eventually failed.
Fix: 74ls02 at N8.
This pissed me off because I had the whole board running then the star field decided to shit itself and It was the only thing running when I first got some picture out of the board. Seems the circuit that puts the star field on the screen is around the top right of the video board.
Its a interesting Fact that all the Bad ics except the 74ls365 were branded F.
Summary:
15 bad IC's
Green Video Board
Bought 3 bottom boards from E-bay for parts 1 already had some chips missing mostly just the ram chips the other 2 were pretty much complete except the blue one was missing all the proms. Fired up the green board, colour was off big time looked mostly blue and all the character sprites had vertical lines in them which I could tell straight away was a ram problem namely one or both of the 2148's.
Problem: Vertical lines in the sprites.
Fix: yep was the 2148's, put new sockets in and they worked fine.
Problem: Noticed the red was missing out of the screen, red text was missing and the red on the wings and body was missing in the sprites.
Fix: Easy fix again, the trace between the pin for the red RGB video output and the near by resistor was bad. Fixed it and the board was sweet. Just going to do the off pink resistor fix to this board then ill be happy.
Update:
Problem: Boots up then says Ram 4H
Fix: Replaced 2114@6K
Another Blue board
Problem: white screen.
Fix: bad socket for the 6116/6016 ram @ 1M-L
Problem: games boots up then haults with RAM 3H
Fix: Bad 4116 @ 6M
Problem: games plays fine for a few levels then graphics corruption in charachters.
Fix: Bad socket for rom 5R
Video Board Ramblings
Resistors.
R1-100 ohm
R2-220 ohm
R3-220 ohm
R4-1k
R5-1k
R9-470 ohm
R10-470 ohm
R6-100 ohm
R7-100 ohm
R8-470 ohm
A great and easy mod for this board can be found on Jrok's site that fixed the off pink colour these gallag boards have. Also tested and works on the alt type board below.
Gallag Alt Board
This one is the same type of board that was seen on e-bay going under Galaga PT 2 although this one has been programmed with the Namco set. This board has no SBC rider board and the ribbon cables are in strange positions with one at the top and to the side of the board.
Interesting to note the board seems to run a hell of a lot faster than a regular Gallag or Galaga board.
Edit: I now know this is because of a rom hacked used to advance the game forward, not sure about the amount of levels advanced but i guess at least 5 or more. Rom 3 is the one that has been modified, you can see from pic one it has a larger sticker on it. Just confirmed this playing a normal game, the hack starts on level 8.
Problem: boots up with RAM OH
Fix: Bad 6116 ram on video board @ L1
Resistor values on Video board
R1-100 ohm
R2-220 OHM
R3-220 OHM
R4-470 ohm
R5-1 K
R6-100 ohm
R7-100 ohm
R8-470 ohm
Jrok's off pink colour correction works a treat on this board also.
Attached is pictures of the top and bottom boards plus a pics of the off pink and colour corrected game. I don't think the pics do it justice but. Pinouts are also below taken from Mikes Arcade, they are basically the same as the Midway/Namco ones but have the video inputs at the connector and not a seperate plug on video board, I slightly corrected them as the Speaker + and - are around the wrong way.
Update: Just a update on the last board I posted. I just popped it in a cab and started playing it to my surprise the first challenging stage is more like level 10's challenging stage with those mosquito type bugs flying down. I thought it was strange when I rack tested this board it reset after level 250 usually it resets at level 255. My conclusion is this board has been made harder by advancing the game 8 levels so in fact you actually start the game on level 8 by the regular board, no wonder the damn thing seemed faster on the first level. I am still yet to determine whether its a software or hardware mod, I'm going to test the roms and find out. Personally I don't like it and will try to get my 5 levels back. I recall somebody had claimed that they achieved this on a similar board by tieing down address lines which I now know is utter BS. Its just the way the board was designed.
