Recent content by miata

Briefly update. I call this repair now successful. My Vectrex always turns on, also after many days stored in the cold storage room. Sometimes it takes 30 seconds or so until the unit turns on for a cold start. When stored in the warm apartment it comes right on. I also took the Vectrex to a...

Hi rhyoraptor. It’s Christmas and I wish a new old stock Kim-1 computer from Santa Clause 😊Seriously, I have just found this thread. Are you still got one Kim-1 left for sale? Merry Christmas 🎅 Denis from Germany

Good morning demonlg Don't give up! I know how frustrated you are now but once again - make a break and step back. Consider how much solder work you have done to this board especially when installing all of these sockets. It may happened to you that you have an intermittent contact issue. You...

X looks really weird. Fully agree. The problem is obviously on the logic board. Can you please also scope pin 10 at IC305 and pin 14 at IC 303?

Good morning. looks like you did a Night Shift. Thats sad that replacing IC401 did not solve your problem and you probably feel frustrated now. Happened to me many times too. But still worth trying to adjust your vectors again. You replaced a chip related to that and according to my experiences...

Yes. But it became a long story 😳 better to start with post #67 there when Dave and myself startet to look around this chip https://forum.vcfed.org/index.php?threads/vectrex-newer-version-no-buzz-troubleshooting-sound-but-no-video.1242748/

I guess there is a good reason why it needs to be bi- polarised. I found it here https://www.ebay.de/itm/334580761407?mkcid=16&mkevt=1&mkrid=707-127634-2357-0&ssspo=k74YYNnATeG&sssrc=4429486&ssuid=EkfxKFnbSNy&var=&widget_ver=artemis&media=COPY

Haha. 😁Yeah. Sometimes the problem is sitting in front of the screen😉

I agree with Dave. Looking into the Troubleshooting Manual - a faulty IC401 can cause a number of picture problems: picture distortion Picture off center Vertical size incorrect Ripple in picture shaking or flashing no vector intermitten vector replacing this chip fixed my missing vector...

Success! 😊 Today I found some time to take care about my poor Vectrex. After switching on and unplug/plug in the VDC connector to the digital board multiple times I never got the -13V available at the connector pins. It helped in the past but not anymore. I measured +5VD and -5VDC on the major...

Update. I have now checked whether all capacitors I have replaced got continuity on both ends. I have checked by following the traces vs. the schematic. On the analog board they look all good. Now I have this odd condition that the Vectrex only shows a dot on the screen and there is no game...

Good evening. This is really a strange behaviour. Could be a capacitor problem but also a problem with an IC. Did you feel with your finger whether any of these ICs is getting hot over time? As you now have socketed many of your chips you may want to replace one by one to see whether it makes...

Hi demonlg, well done (y):) Dont worry about the checksum. Meanwhile I worked on 3 different Vectrex Units and the checksum was always different. It does not bother the gameplay. I see your picture is not centered properly (fix this first & use the neck rings for this) and the picture size...

Indeed. This is far off. Should be in a range of -4,8V to -5,2V Did you measure this value right at the 7905, at the output pin? What’s the voltage at the input pin (the middle one)?

😁 Haha. I don’t feel like an expert. Seriously. The Vectrex is still a kind of (beautiful) mystery to me! But good to have masters like you here, Dave 😊