Hi guys,
I'm slowly making progress on my Black Hole machine. I will post more pics as I go. Machine was purchased not going or tested so the first thing I did when I got it home was cut the power cord off - so I wouldn't be tempted to turn it on and see where it was at. In hindsight, this was a smart move - as I've read you can do more damage by rushing these things.
I didn't take any photos of it complete when I got it home, as the leg brackets were stripped, so I pulled it down straight away. The cabinet was emptied and floor replaced. I still need to cut the speakers, vents and switch hole. I should have done this before glueing it in, but I'll find a work around.
As far as the electricals go, lots of work in this area. I removed the board panel from the actual backboard, along with the power section so I can work on it upstairs. The transformers have been jumpered to 240v, caps replaced (orange one gone), bridges all tested and wiring visually inspected. Powersupply was removed and all sections rebuilt as per Clay's guide. Grounding mod completed as well. Tested once finished and all voltages 100% spot on.
Next was driver board. As per another thread I was having issues with readings on ALL of the transistors. Turns out my DMM was a turd and only putting about 1.0v through on diode test. Not enough grunt to test them properly. Tested with Silverballs DMM, had a couple of small issues with that board and he kindly swapped me for a near NOS one (nice and clean!). Ground mods done to driver board, tested all now 100%.
CPU board...Not booting initially. U4 & U5 swapped out. Nil value. Thought it was displays, all removed and tested (they are OK). Clock tested. Was OK, but replaced anyway. Reset section working 100%. IRQ is stuck high (and still is) so I've removed U2 & U3 and have a updated replacement on the way. I used the strip sockets on these and I think I'll use them in the future too. Hopefully in a week or so I will be in a better position to know. New PROM1 on the way too just to be sure.