Archived from groups: rec.games.video.arcade.collecting (More info?)

Hello,

I screwed up big time. If you have been paying attention to this board
for the last couple of days you might have seen my earlier posts. I
finally got the chassis working after a cap kit.

Well, here's the problem. While I was trying to find the B+ voltage,
the leads slipped and ended up shorting from the tr502 blue lead to the
ground. Obviously, this is really bad. The monitor immediately
stopped working. The fuse burned out and I replaced it today. After I
did this, I fired it up and it survived for about a second before the
fuse broke again.

So.. Any ideas? I'm thinking I might have to replace both TR501 and
TR502 but I'm not sure at this point. There is a whole power board on
this chassis and I'm afraid it might need to be replaced completely.

Once again, any ideas would be appreciated. Either reply to this or
e.mail me at jake dot vanorder at gmail dot com.

Thanks.

--jake

Archived from groups: rec.games.video.arcade.collecting (More info?)

502 should be replaced for sure and when that went it probably took 501
with it. Mainly replace those two transistors and that should fix it.

That power board unplugs easily for service. Just unlatch those black
plastic 'pull knobs' at each end of that power board assembly and pull
the board straight up. Be careful to look first at the connector on
this board before pulling it up as the factory put a small white
'beaded' wire tie thru a hole in the circuit board to secure it to the
main monitor board. You'll have to cut that wire tie and discard it.

Archived from groups: rec.games.video.arcade.collecting (More info?)

Ken,

Thanks for the reply. I'll take a look at replacing those two
resistors. Do you know where I can pick some up?

As for the power board, I think it is also screwed in at two places but
it should be no problem to remove.

Thanks for the help.

--jake

Archived from groups: rec.games.video.arcade.collecting (More info?)

Those are transistors not resistors. They are located on the plugin
power regulator board at the far left (as viewed from the rear of the
monitor). Any good local electronics parts jobber should have them.
Look in your Yellow Pages under the heading, "Electronic Parts &
Supplies". If no local suppliers then mail order them from Bob Roberts.

The power/regulator board on a 4600 series should not be screwed in
place. As shipped from the factory it is only held by a black (or
sometimes white) plastic pull knob similar to the old Datsun car
fusebox cover lock knob. Simply just pull the knob up about an eigth of
an inch to release the latch prongs under it. Then cut the little white
plastic beaded wire tie near the connector. The board pulls straight up
and out for service.

Archived from groups: rec.games.video.arcade.collecting (More info?)

I didn't know about that knob release. I saw those but didn't know
what they were for. Weird. I'll look up the parts when I have a
chance.

Thanks for your help!

--jake