Tech: Amplifone Deflection Board Help Needed

[Guest]

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

I have an Amplifone deflection board I am trying to repiar. It is out
of a SW that had a bad high voltage board. Here is what Ive done thus
far. I have replaced all the caps, 2n3792's, 2n3716's, 3904's / 3906's
& mpsuxx's, reflowed cold joints and cut and resoldered all wires. I
have also removed the 0 ohm jumpers and replaced them with wire. R29
gets very hot, so hot you cant touch it. R6 is considerably cooler, you
can touch it. Spot killer is not on initially but will come on if the
game is left on for more than a minute. Spot Killer comes on right
after fuse f2 pops. I do not have any burnt components or anything
obvious. Sometimes R73 will puff a little smoke when the game is
turned on then stops. I have tested all the big 2w resistors and many
of the smaller ones....all are in spec. I also have no picture
(amplifone 19" tube) at all or any signs of life.

Boardset is known working 100% and I have a ArcadeShop HV unit..all of
which work perfectly with another tested working deflection board in
the same cabinet.

Any suggestions?

Thanks,

-Troy

 

[Guest]

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

Troy,

I actually had this big, descriptive thing wrote to help you out, but
as soon as I clicked "post" a google server error popped up. Now I
don't want to type it all over again =(

They need to fix this thing.

- Matt

 

[Guest]

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

Matt,
Thanks for the attempt! I figured I had a short or soemthing open
somewhere....but I couldnt put my finger on it. I started to recheck
everything. I pulled the 3716's, 3792's and the 4 MPSUxx's. They ALL
checked good out of circuit. I even installed new insulators too. I
started to test/compare resistor values against my know working board &
the Amplifone part list with values. I found R31 was reading 19 mega
ohms on the bad board and R31 on the good board was 3.3ohms....DOH!
according to the manual it was supposed to be 3.3ohms. I didnt have a
new one so...I desoldered the 3.3ohm resistor and put it in the bad
board. I fired it up and bingo..I heard the deflection start
crackling. I checked the picture and I saw SW on the screen. Go
figure.....

-Troy

 

[Guest]

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

Thats funny.. I actually listed those two resistors (r8 and r31) as two
of several to check for problems. Glad you got it going.

- Matt