my new defender, pink background?!

[gwarble]

small update and a little clarification

when i said it wouldnt go to "initial tests" or advance settings when in "pink background" mode i was wrong... it appears to be cycling through but just not displaying text, or displaying black text on black background...

transistor swapping didn't do anything


i got anxious and turned the voltage up higher than i wanted to... and i saw the pink background turn to normal mode, at about 5.25-5.3 volts... varying between there and 5 i got intermittent results, but definitely more likely to go normal with higher voltage!

still leads toward some circuit on the board that needs a closer inspection... what about the caps near the power connector? the only reason i'm thinking that is "warmup" symptoms i've seen are usually monitor and cap related... they dry/wear out... worth swapping them out?

one side effect, the voltage change corrupted the high score and settings data

thanks again everyone, i'm playing more and more defender which is awesome, and its hard as hell! i totally suck at it, but the pace, graphics, and reaction times are very robotron-esque which is awesome

- gwarble

 

[gwarble]

re-reading this thread before heading to bed, i realized what dokert meant by POC (we use POS in my neck of the woods) and you're right, it is a piece of crap... and i've only ever spot checked the voltages, maybe my POS switcher is warming up and varying voltage...

supposedly from the previous owner, the original PS gave this pink screen, then a hacked in switcher didn't fix the problem and it sat... then my replacement switcher gave the same symptom... so maybe a problem with the original ps gave a low +5, the replacement switcher was as much of a POC as mine, and still had low +5, and its a voltage problem still, which would be great

or something on the board is varying with heat/time and varying the voltage on boards (like those caps?) but that will be obvious when i monitor the voltage as it "warms up"

so thanks dokert, i also got my ps rebuild kit from bob roberts so i'll get that one wired back in and see if it helps


any danger in running this at +5.3?

thanks
-gwarble

 

[gameonnow]

Hope you do fix it as I do have the same problem. I also use a SM psu and it does seem that the board does loose a lot of voltage before it gets to the otherside of the board, original the board I had refused to work given a random error each time. The connector reads 5.0V but the voltage on the logic chips at the far end of the board only read 4.7V, so I jumpered it so the far end of the board had proper 5V and it did work but then it got the pink screen, so maybe I will try to increase the voltage slighly.

A 5% increase is within acceptable limits.

Although one thing I will do is to replace the 4116 RAM with 4164 RAM (and mod the board so it does not use 12V and -5V and jumper the 5V to the 12V line on the board) as it should work better and lower the voltage requirements.

 

[Peale]

If those caps are original on the board, definitely replace them.