68kMLA Classic Interface

(5) Troubles of the transistor Q1 on the video board. The video board is a small board where the CRT socket is soldered.

(5) If none of the above doesnt't work, replace the transistor Q1 (2N3904, NPN transistor) on the video board.

I got my hands on another video board, swapped them out, and it now works perfectly. Still haven't figured out what was wrong with the original video board; that's for another day.

[SIZE=9pt]Symptoms: [/SIZE][SIZE=9pt]There is raster but no video display. The raster is very bright. Horizontal scan lines are visible.[/SIZE]


[SIZE=65pt][/SIZE]
[SIZE=9pt]Probable diagnosis: [/SIZE][SIZE=9pt]The problem is on the CRT socket board [/SIZE]

[SIZE=9pt]Solution: [/SIZE][SIZE=9pt]Check/replace the 2N 3904 transistor (NPN, 0.6A, 1/2 watt, TO-92) at board reference Qi. Depending on the board revision Q1 could either be on the left or on the right. Also see the prior entry. [/SIZE]

One of the biggest issues i have with the SE/30 is UE8,  there is a cap right there and it leaks its OOze right on/in UE8,  Sometimes the I/C goes bad because of this.   Sometimes you can hot air flow off UE8,  And flux&wick clean up the pads… get some fine grit sand paper and clean up the legs of UE8 and re attach it and it will work fine.

but sometimes you need a to replace it.

UE8 issues = No Video
UE8 issues = Video with lines (pin stripes)
UE8 issues = Can give you the same symptoms as a bad Video board ( on the back of the crt )

Here is the big one. and yes this has happen to me now 2 times.

UE8 issues = Depending on on what level of damage the cap goo has caused, And how the I/C has failed — can cause a No tone, No Boot!  Yup!

I was surprised my self, I found this one by accident...

^^ one other cause for Pinstripes in your SE/30 Video ^^

Datalines 0-7 come from the VRAM.
Sometimes the via's can rot (via's right near UE8) that are datalines  0-7 coming from the VRAM.
So in this instance you have to run a patch wire from the correct pin of UE8 to the vram.

You can check what one is bad with the se/30 schematics and and multimeter and check for 000 ohms 0-7
and if you get one with no continuity, that is the line.