Hi all.  Happy Thanksgiving to those in the US.   I went over to turn on my decked out A4K this morning and felt a very distressing ZAP when I touched the case.  Now when she boots, I only get a black screen (no video).    When I give her the three fingered salute, the caps lock light does blink.  And the caps lock will blink if i press it on and off (until the buffer fills up).    I removed all the goodies, and am just running the base 040 config. No change. This machine was recapped, and ran for about 500 hours with no issues.  Im ready to just sell the parts on feebay, and send her down the line. I do have a scope to test points on the board, but I think this repair is beyond me.  Any last words of advice before I give up?

Sounds like a case of the accelerator not making good contact on the cpu slot to me. a static discharge to the case wont hurt anything, its grounded, if you have to have a zap, that is the best place and not to some board or chip.

Sounds like a case of the accelerator not making good contact on the cpu slot to me. a static discharge to the case wont hurt anything, its grounded, if you have to have a zap, that is the best place and not to some board or chip.

Very good advice. I agree that the static discharge to the case shouldn't have hurt anything.

Thanks for the advice. I gave re-seatting the zorro/040/ram boards another go and still no dice.  I could take the scope out and start testing common faults I guess. Found a similar sounding issue here:  http://www.amiga.org/forums/showthread.php?t=65842&highlight=4000+black

Did you re-seat the A/V board connection as well? The board is at a right angle to the motherboard and the corner of the A/V module farthest to the inside of the 4000T can work up with heat cycling. Push down on that corner. If you know the 4000T is booting all the way to the OS, you could even try leaning the 4000T over on its side with the cover off and pushing down on that corner of the A/V module while the machine is on.

Another thing to check is the AT power supply plug where it plugs into the motherboard. Pull this out and look for any burnt places (common problem on 4000T). Replace the power supply if there are any burnt places on the plug, otherwise plug it back in. NewEgg had new AT power supplies last time I checked.

It would be a good idea to try another accelerator board if you have one as well.

This is a Desktop unit but thanks none the less for the advice.  I will take a closer look at the video connection though.  I don't assume she is booting to anything. I have attempted to boot from the known working CF HD and from an emulated workbench floppy.  When i boot with the latter i can see the disk being read via the read light.  We can assume it is booting up but I don't know for sure.  such a noob at tshooting this things!  lol  I do not have another accelarator card to try at the moment.     I had checked the voltages on the power supply and they checked out ok all around.  I don't recall inspecting those connections though, so will do so. Ill check back in here in a day or so with any news.  Thanks again.

You might double check the jumpers and make sure all is ok still, physically move them to make sure you have contact. Have you hotplugged anything in? video,mouse etc/   i seem to think a dead cia can cause a black screen but thats just a guess.  can you hold the mouse buttons down on power up and get tothe early startup by chance?  what monitor do you use?
The caps light you mention suggests the cpu board however. was the A3640 040 board recapped also? its not uncommon for cap leaks to eat a trace running near or under the capacitors.

I saw your post on EAB,you didnt mention it had a indivision here. more than likely its came loose,isnt making good contact or its popped a solder joint on the video chip where its soldered to the motherboard. Check it with a 15khz monitor on the native port.