Star Wars - bad picture 'wobble'

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I think there must be something in the air, but over the course of two weeks 5 of my machines have packed up. I have checked voltages on all and replaced / checked fuses. Reseated anything that could be reseated and checked all harness connections. These are the faults:

Star Wars (a) - PSU working correctly, no sound, display or leds on PCBs. Voltages seem fine. But I am not sure if I am checking everything I should be.

Star Wars (b) - PSU working correctly, sound works. Display screwed in hori axis which I guess means HV PCB prob? It's not squished into one line vertically tho - the image appears once every second for a fraction of a second, and takes up about two inches wide in the centre of the monitor vertically. Whistling noise when image on screen.

Asteroids - Nothing at the monitor at all. Fuses blow on one of its PCBs at start up. I did find the guide on Atari vectors but its suggestion that perhaps transistors are shorting to the chassis hasn't fixed the problem. There doesn't appear to be a short with the collector and the mica looks OK.

Joust - Passes initial checks with a zero on 7-segment display, monitor shows all systems go, very briefly the beginnings of the high score table then nothing. Test mode doesn't work (can't get into it as no screen), no sound. It looks like a bad contact somewhere because I can get different things to occasionally appear on the 7-seg display, but have triple checked and everything looks good. Ideas would be appreciated.

Dragon's Lair - ROM error on boot SOMETIMES, random crap in the score tables every boot. Occasionally boots OK but fails when trying to play the game. I guess it's ROM so will replace the lot if I can find replacements.

Sorry I can't be more detailed, but I am so close to buying a bunch of LCD displays and emulating them

Cheers

[drawfull]

Anyone? Joust especially is driving me mad.

I have hopefully got new ROMs for Dragon's Lair shortly.

[boardjunkie]

Vector games are a PITA to t-shoot without being in the same room with it and ruling things out one step at a time. Thats what needs to happen.....bribe a good tech who knows vector games to have a look at them.

[ed12]

hi

this common

Star Wars (b) - PSU working correctly, sound works. Display screwed in hori axis which I guess means HV PCB prob? It's not squished into one line vertically tho - the image appears once every second for a fraction of a second, and takes up about two inches wide in the centre of the monitor vertically. Whistling noise when image on screen.


hot >horzout-put-transformer + chk horz output transistor,also chk the sweep cap's
if they shifted in value which is about 80% they did u will want to replace them

Asteroids - Nothing at the monitor at all. Fuses blow on one of its PCBs at start up. I did find the guide on Atari vectors but its suggestion that perhaps transistors are shorting to the chassis hasn't fixed the problem. There doesn't appear to be a short with the collector and the mica looks OK.

if u took them out
and metered them then replaced them,then u will need to replace the mica's,yes they fail because the grease dry's up,and there is no longer any heat-transfer ratio


Joust - Passes initial checks with a zero on 7-segment display, monitor shows all systems go, very briefly the beginnings of the high score table then nothing. Test mode doesn't work (can't get into it as no screen), no sound. It looks like a bad contact somewhere because I can get different things to occasionally appear on the 7-seg display, but have triple checked and everything looks good. Ideas would be appreciated.

chk your power supply for stable voltages both at the power supply and there asc. header's,
plus yes the ram get real crapy

ed

[drawfull]

Thanks Ed, I have ordered new ram for the Joust.

I have managed to get one SW working, but it looks to be by the skin of its teeth. I think I saw a vid on YouTube that Level42 did of his monitor with dodgy deflection but I can't find it now - Basically I have bad pincusioning and wobble that hurts your eyes on the left and right extremeties of the WG monitor. I don't know if it's always done this as it died very shortly after I got it, but I have swapped the harness over and that fixed the problem - there was an intermittent connection on the other harness but I don't have a crimping tool handy so to swap was the easy option.

Any ideas on the wobble?

Thanks

[ed12]

hi

in the wg in question
is there a small stand up board over by the :ihvt-flyback:
if so does it have a few >2< pot's on it
it may connect with a 7-8 pin plug ie u insert board
if so it is your pin-chussion correction board
i have removed it before to fix :wobble:
also u might want to chk into the 117vac switcher cap's
if they have not been replaced do so now
if they have double chk them to spec
i know some time's tech's will replace a 47uf with a 100uf
but in these case's it can be a bad idea
also chk your sync /rgb/ground's

ed

[drawfull]

Well I've been busy today, cap kits and AR2 rebuild kits on the way for SW

New rams for Joust on the way

All great

[drawfull]

Well the ram didn't fix Joust so I am led to believe that I either have bad ROMs or the ribbon cables are dodgy. Tried to buy standard IDE cable today to replace and the only thing available was an ULTRA ATA type. I don't think this will work, so didn't buy it but does anyone know if it will? The pitch of the cables looks too narrow.

Thanks in advance.

ps got my cap kits and will do that this weekend, but having left SW on for 24 hours, the wobble has gone 

[ed12]

hi
as to the wobble,that could be main board power supply realted
ie the cap's in them go also

for the joust i will chk in my warehouse ltr tonight when i go to finish a machine

ed