shoggo147

Hi there, I am looking for a replacement ANTIC IC for my Atari 800 I need the PAL version as its for a UK version of the machine Part no on chip is: CO14887-03 Thanks in advance

Thanks all for your advice. I have managed to solve the problem, it was the ANTIC chip as suspected. Swapped one out of my 800XL and the 800 then booted and ran fine. Jut need to find another ANTIC IC now if anyone knows where I can get hold of one.

Hi James, I found a Star Raiders cart. The link below shows what happened. Its similar to the others where the sound and sprites seems OK but other graphics are corrupted. http://youtu.be/JQ_3KWuinz0

Hello All, I just purchased an Atari 800 but am having a problem at switch on. Basically I get a screen full of zeros, when I power up with no BASIC or game carts installed. I have the OS cartridge fitted in slot1 and 16K carts in slots 2 & 3. To power the computer I am actually using a VIC-20 power supply but I checked the spec and this is almost identical to the Atari 9V AC power supply, so I am sure this is not the problem. Initially I had an additional 16K RAM cart installed but with this I just got a blank red screen at switch on, so removed it as I presume there is a fault with one of the RAM chips. If I swap around the remaining RAM carts it does not make any difference. I have also tried re-seating all the chips on the carts and inside the machine and cleaning all edge connectors From a quick look around on the internet it seems like it could be a fault with the ANTIC chip. I do have an Atari 800XL but I am not sure if I could swap the ANTIC chip from this to test. I have also tried a number of game carts and found the sound and some graphics e.g. sprites, do work fine. See below links to the three I have tried http://youtu.be/xmrMnIcxV4I http://youtu.be/wdNFOZFFdwE http://youtu.be/-aMSCMpIx8M Any suggestions would be much appreciated.

I have finally got back to trying to sort out my Vectrex with jumbled up vectors. After the suggestion that it may be due to power supply ripple I checked out the Troubleshooting Guide which recommended checking ripple at the input of T503, which should be no more than 50mV. Below is are screenshots taken from +9V & -9V inputs of T503, which both show ripple of over 500mV Screen shot of ripple on +9V input at T503 Screen shot of ripple on -9V input at T503 My conclusion is to try replacing 2 x 10,000uF capacitors C117/C118 and 2 x 4,700uF capacitors C109 & C119

I have no other carts to try at the moment, didn't really want to spend more if I can't get it working. I might try replacing caps related to the power supply output (such as C110/111 & C120/121/122) , as it could be psu ripple as the first reply suggested.

Hi All, Hoping someone can help with a Vectrex I purchased recently, which had the usual white dot problem but had working sound. I replaced a few of the ICs on the bottom PCB and eventually got Mine Storm to boot up. However a few seconds into the game the text where the score is shown at the top starts to drop down the screen. At the same tim the vectors start to become miss-aligned. I tried replacing 3 x caps on the bottom PCB that were easily accesible but it did not help. The system does still sometimes boot to a white dot screen and I found if the 4-pin power connector on the bottom PCB is pulled off and replaced it then works OK again. I cleaned this connector with contact cleaner and re-flowed the pads underneath but it still seems to have the intermittent bootup problem. Has anyone got any ideas what could be wrong? I have added a video below.