Black screen :-(

macc · Post by **macc** » Wed May 25, 2011 3:55 am

I had a Vic that worked until it fell off a shelf that collapsed, everything seems fine, not even any scratches on the case, opened it up, fuse ok, all chips reseated, no loose wires but on power up, black screen, tried with a cart in, no difference, any ideas where to start looking?

Bacon · Post by **Bacon** » Wed May 25, 2011 5:40 am

macc wrote:I had a Vic that worked until it fell off a shelf that collapsed, everything seems fine, not even any scratches on the case, opened it up, fuse ok, all chips reseated, no loose wires but on power up, black screen, tried with a cart in, no difference, any ideas where to start looking?

Probably a small crack somewhere on the PCB (mainboard, that is). Time to get that multimeter out!

macc · Post by **macc** » Wed May 25, 2011 6:15 am

Yeah, I thought that too!

As an aside, theres power to the 5v line of the user port but not to the cassette port, Ive never had one and not the other before, maybe this will help in isolating the fault and give me a smaller area to test

macc · Post by **macc** » Wed May 25, 2011 5:43 pm

Ive been all over the board with the multimeter, dont think theres anything Ive missed but theres continuity on all traces and no signs of cracks. Changed the kernal out just in case, same problem. Cant get my head round this one..

macc · Post by **macc** » Mon May 30, 2011 5:46 am

Anyone any ideas?

damnstraight · Post by **damnstraight** » Thu Jun 02, 2011 7:44 pm

If you do not have 5volts it will not work. Have you checked the regulator. I would start there.

dabone · Post by **dabone** » Sat Jun 04, 2011 6:46 am

I have had that problem with a couple of vics. Is it the model with the 2 prong power cable? If so I've had to replace the power switch. Black screen, but the led lights.

You can test by jumpering the switch out of the circuit. Just add a couple of wires to the underside of the board.

Later,
dabone

macc · Post by **macc** » Mon Jun 06, 2011 7:57 am

Ill check the regulator, I do get 5v to the user port, just not the cassette port. Ill try tripping the power switch too (its the round DIN plug version btw)

macc · Post by **macc** » Tue Jun 07, 2011 10:43 am

I now bizarrely get 5v to the cassette port too, tested the 5v reg, ive got 0v,12v centre pin and 0.05v

e5frog · Post by **e5frog** » Fri Jun 10, 2011 4:21 pm

Maybe some resoldering needed.

macc · Post by **macc** » Fri Jun 10, 2011 6:51 pm

It did have quite a nasty bump when it hit the floor, ill go over it with my brand new soldering iron later, but save me going over the whole board, anywhere I should think about concentrating my efforts on first?

e5frog · Post by **e5frog** » Sat Jun 11, 2011 7:23 am

Start with the things that have the largest mass then...

Who knows what that bumped caused and if there were poor joints already, did you try turning it on and then press/wiggle all components and see if anything happened?

macc · Post by **macc** » Sat Jun 11, 2011 8:08 am

yeah, tried wiggling components from the off, no change. Ive been around the board freshening up a lot of the joints, still no joy as of yet

e5frog · Post by **e5frog** » Sat Jun 11, 2011 9:29 am

If the board is OK and no components are loose - what component would break first if it was dropped?

If a component has come loose and lifted the copper and solder from the PCB, tearing away the trace so that there's no connection and then flexed back again - that will be very hard to find...

Did you measure the fuse, maybe it's just almost OK. What if you short the fuse for just a short while, any difference?

I guess if you'd followed my acquaintance Bacon's advice and checked ALL traces with a multimeter you'd be about done now. If you don't find anything else that's probably what you need to do.

I'd check GND and +5V on all components first to see if they all have power.

Maybe also see if Ray Carlsen has any general advice about a "black screen" unit. Maybe it was OK after the fall but something else just happened to fail when you turned it on.

Denial

Black screen :-(

Black screen :-(

Re: Black screen :-(