Picture: Mac Se,My Video Board is bad...

#1 Sat, 24 Mar 2012 - 05:48 68kMLA

this is what its doing, if i swap the video board on the back of the tube with a working mac,

it works fine, i already re-soldred all the connections on the back... nothing looks cooked...

Any suggestions?

#2 Sat, 24 Mar 2012 - 15:47 68kMLA

Have you tried checking all the connections with a volt ohm meter?

Since you have a working specimen, if they are identical, try comparing them. Make sure none of the diodes have reverse bias, the resistors match ohms (this depends on their tolerance range), and the capacitors are within range.

It is not that complicated of a board, so use a paper clip affixed solid to a test probe on one end to check all the pins on the power connection, the electron gun pins, all the traces, and all the components.

#3 Sat, 24 Mar 2012 - 19:00 68kMLA

your video output transistor circuit is bad for sure.

check the output transistor for shorts, and nearby resistors for opens.

#4 Sat, 24 Mar 2012 - 22:59 68kMLA

ok thanks... yeah that sounds simple enough, at least it somewhat works

gives me hope!

ill do a compare!