Odd Tempest Power Issue

The_Director

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Running out of ideas here, so hopefully someone can help me. I've got a Tempest that was working fine and now DOA. Spot Killer is on. ARII has had all new caps and sense mod done to it. Board is getting .8volts DC at 5volt test point. However, ARII board is putting out a solid 5.1v and the edge connector gets 5.1 and the continuity between game board and edge connector is there, so why is it only getting .8v to the board and not allowing it to boot? What am I missing?

Only other thing I noted was 10.3 unreg is hovering around 12v but that proper 5v from edge connector should still boot the board.

Thanks!
 
Just had this exact same situation with a Tempest I had repaired which included a full rebuild of the A/R board....+5 volts at the pin on the edge connector was fine, but when plugged into the game board itself, only +0.8V coming off of the board.

For whatever reason, the new 2N3055 bottlecap transistor that I had put on the A/R board failed. Put in another new one last night, and I was back in business.

Annoying, but I guess it happens sometimes with new components...

Jon
 
I lean towards 3055 bottlecap. same thing happens on Williams power supplies if the 6057 isn't connected properly.

a lot of people are reporting that the 3055s Bob Roberts sold them were bogus. I did my Defender power supply years ago with one of his kits because I didn't know better then and it's still working however.
 
Just had this exact same situation with a Tempest I had repaired which included a full rebuild of the A/R board....+5 volts at the pin on the edge connector was fine, but when plugged into the game board itself, only +0.8V coming off of the board.

For whatever reason, the new 2N3055 bottlecap transistor that I had put on the A/R board failed. Put in another new one last night, and I was back in business.

Annoying, but I guess it happens sometimes with new components...

Jon

Awesome! I'll swap a new one tomorrow and report back. Sounds like the exact issue, so hoping this is it!
 
I lean towards 3055 bottlecap. same thing happens on Williams power supplies if the 6057 isn't connected properly.

a lot of people are reporting that the 3055s Bob Roberts sold them were bogus. I did my Defender power supply years ago with one of his kits because I didn't know better then and it's still working however.

Interesting in that the one I had installed was from a recently acquired A/R rebuild kit from Bob, but I have never had problems with stuff I've gotten from him previously and over the course of many years.

But the "new" transistor I swapped in last night was from a Williams PS supply rebuild kit that I also got from him several years back but had not had to use so it was just sitting in one of my parts boxes for at least 5 years, probably more. It was from a different manufacturer than the one that failed.

I'll leave the game on for a bit more tonight to make sure it's OK, but I ordered some more from Ian Kellogg just in case :) .

Hopefully, Bob just got a bad batch...if and hopefully when he comes back, we should let him know.

Jon
 
lots of complaints about Bob's stuff though. sucks.

BR had lots of bad flybacks too and you know "all sales final" is the problem because everyone can get a bad batch of something but when he won't stand behind it that is when there is a problem.
 
Yep, was the 3055! It had been replaced, not sure how long ago but from previous owner, so maybe only a year or two ago. This one is on location too, so on for 10 hours a day, 7 days a week which could account for premature failure. Thanks so much guys for the lead, this one had me scratching my head!
 
Glad you got it working again!

Was the bad 2N3055 a Toshiba component (with red lettering)?:

Bad2N3055_zpshebh5qfi.gif


This is the one I had gotten from Bob Roberts that I'm now hearing has been failing for a lot of people who also got it from him.

Mine barely lasted 15 minutes unfortunately after I installed it as part of the A/R board rebuild.
 
they were the fake toshiba trans that china had flooded the market with.
if u look real colse and i mean colse u will see a small c
that makes it china build..
if u have more ? through them out as they will do the same thing.
learned the hard way

ed
 
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