I just replaced the 7805 again this time it didnt work. Ill look for my volt meter then Ill take this high res pic. I stil only get a black screen that blinks once. Now Ive been pushing down on the card slot a bit & I get a noise from the TV sometimes.
The 7805 is getting very hot.
Check voltage to some of the chips to see if the are powered.
How hot is hot? If your finger is getting burned in less than a second then there is a problem.
7805 dump alot of power into heat and will run quite warm.
Clowns Suck
Clowns Suck
The ground warms up fairly fast. In a second I can feel more heat from it than I should, I wouldnt say Im getting burnt but its still hot enough.
The 7805 will get hot when run like that, which is why there's a large heatsink that it screws to in the case.
Check for +5V with the voltmeter... looking at the front of the regulator, put the black lead on the middle and red lead on the right side. It should be close to +5V. If not, move the red lead to the left and make sure you have higher voltage (this is the voltage of the power supply you're using... probably ~9V).
If you do have +5V, then something else in the circuit is bad, don't bother looking at the voltage regulator. If you don't, verify that your power supply is still good. If that checks out, use your ohmmeter to measure the resistance between +5V (right pin) and GND (center pin). If it's really low, there's a short somewhere (could be a solder glob, metal shaving, bad chip, etc).
DogP
Virtual Boy Lives @ Project: VB
Ok so the voltage regulator measures exactly +5 volts so that checks out. Now when I Check it's ohms the meter gets pinned all the way to the opposite side. And from what I can tell that means its measureing less then 0 ohms, am I doing somehting wrong?
ok so when the system is on it goes off the chart, when its off the ohms measure 5 on the left pin the I and 2 on the right pin the O
You don't need to measure resistance of the regulator. If it's 5V then it's good. Also, you didn't do it with it powered up did you? That can't be good on your meter or the regulator.
Did you measure the voltage on the processor yet? I can't tell for sure from your picture which chip it is, but it should be labeled IC1 and Zilog & Z80 should be printed on it. The corner pins should be be numbered as well. Pin 11 is VCC and should be 5 Volts. Measure from there to ground.
Also check the voltage on MC1377. Pin 14 should be around 12 Volts. I'm not sure what that chip is labeled on the board.
Last edited by jb143; 01-24-2012 at 04:40 PM.
"Game programmers are generally lazy individuals. That's right. It's true. Don't let anyone tell you otherwise. Since the dawn of computer games, game programmers have looked for shortcuts to coolness." Kurt Arnlund - Game programmer for Activision, Accolade...
Ok so pin number 11 measures 5 volts like it should. and since i couldnt find the other chip I just measured all the pin 14s and none of them measured 12 volts. some measured 5 or 0 and one measured 2. the one that measured 2 is labeled 6j02 v7040 then has japanese text and is made by sony.
What did you do exactly? Cut the pins...but not cut enough the first time?Originally Posted by toploaderleo
Clowns Suck
Clowns Suck
I have no idea actually. because I looked and they looked like they were cut enough, but its the only explanation :/
Well I suppose Ill admit defeat on this one and maybe try to get a new Master System.
Just don't bin it, I'd gladly take it if the price was right.
I fix things. You name it, I'll work on it. Want something modded? Recapped?
oh I deff wouldnt throw it out. But if I did sell it. I'd only sell the console, because I use the AC adapter for my SEGA Master System 2. Same with the controllers.
Actually Imma hold onto the system itself. Maybe one day Ill be able to fix it oooooor be able to use it for parts.
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