Donkey Kong Forum
General Donkey Kong Discussion => General Donkey Kong Discussion => Topic started by: chueseman on December 07, 2014, 02:03:59 pm
-
I have a Donkey Kong TKG4 standard cab with a bad PP-7B Power PC Board (TKGU-18-01). The AC transformer is correctly supplying it with 100 volts. The output for -5 volt pins is correct, but there is no output for the +5, +12, and +24 volt pins that go to the CPU and Video PC boards. Any thoughts of where can I send it for repairs? Also any thoughts of any particular component that is most likely the cause?
-
One of my PP-7Bs seems to have died about a week ago as well. Isolation transformer is still fine, but the PS unit itself won't power PCBs. Just spontaneously crapped out (after being on continuously for about a day).
Of course, this came a week after I accidentally caused a short in a PCB I was poking at (after which I smelled that "burny electronics" scent from the PS) so I blame myself. It sill worked fine for a few days, but I guess the damage had been done...
From what I hear, you can do a cap kit on the PP-7Bs, but new capacitors might not fix it because they might not be the problem. Might be a transistor or who knows what else.
Consensus from what I've seen seems to be that parts are hard to find, and overall they're more trouble than they're worth. Everyone just says to replace it with a switcher and use the Arcade Shop PS adapter.
Honestly though, probably just cheaper to buy one of the originals from somebody on KLOV, plus, with the switcher/Arcade Shop solution the coin meter doesn't work (no +24v), and if you're like me, you like to have the coin meter working.
-
I have a Donkey Kong TKG4 standard cab with a bad PP-7B Power PC Board (TKGU-18-01). The AC transformer is correctly supplying it with 100 volts. The output for -5 volt pins is correct, but there is no output for the +5, +12, and +24 volt pins that go to the CPU and Video PC boards. Any thoughts of where can I send it for repairs? Also any thoughts of any particular component that is most likely the cause?
Its probably the voltage regulaters, ic3 (lm7824) and ic4 (lm7812) on the schematic. Tricky to get to and replace on these power supplys but you can get the parts...
8)
-
One of my PP-7Bs seems to have died about a week ago as well. Isolation transformer is still fine, but the PS unit itself won't power PCBs. Just spontaneously crapped out (after being on continuously for about a day).
Of course, this came a week after I accidentally caused a short in a PCB I was poking at (after which I smelled that "burny electronics" scent from the PS) so I blame myself. It sill worked fine for a few days, but I guess the damage had been done...
From what I hear, you can do a cap kit on the PP-7Bs, but new capacitors might not fix it because they might not be the problem. Might be a transistor or who knows what else.
Consensus from what I've seen seems to be that parts are hard to find, and overall they're more trouble than they're worth. Everyone just says to replace it with a switcher and use the Arcade Shop PS adapter.
Honestly though, probably just cheaper to buy one of the originals from somebody on KLOV, plus, with the switcher/Arcade Shop solution the coin meter doesn't work (no +24v), and if you're like me, you like to have the coin meter working.
So if I were to install a modern coin counter would I be able to make it work with the switcher?
also here is a helpful page by bob roberts on how to build a brand new ac power system for your game "http://arcadecontrols.com/BBBB/acwiring.html"
-
Thanks for all the comments. Special thanks to Fast Eddie for pinpointing the problem in the power supply. My machine is up and running again.