WG4600 Eating Fuses

[Scucci]

So, I finally get my Crazy Kong cabaret working a little more (board troubles) and while I'm letting it run to keep an eye on the attract mode to make sure that it keep scrolling through them smoothly and not hiccuping anymore... monitor goes dead.

I unplug the machine and start checking everything... The monitor in this thing is a friggin' Fort Knox as far as fuses go. 2 fuses on the side of the cabinet, and 1 on the chassis.

After first it looks like just one of the fuses on the side of the cabinet has blown... So I replace it, and turn the machine on again. BAM, gone again. Okay... so I pull both, and even though the other fuse looks good, it's gone. So I replace both again... plug it in... ... nothing... BUT, the fuses DIDN'T blow this time... so that's nice. But the monitor is still dead.

I dig out the chassis (what a pain in the ass) from the cabinet and check it over... I don't see any burn marks or anything... So, I try to check the fuse on the chassis for continuity... Thanks to that ever so helpful plastic cover, I can't even get to the leads from up top. So, I have to take the board off, then check the fuse... blown. I don't know when it blew... but, damn son... assuming it blew when the other two did... wow. 3 fuses at once? WTF happened here?

No, really... what happened?

Well, while I had the chassis out, I went ahead and did the cap kit that I got with the machine... no problems, done dozens of them. Easy... LOVE the + and - printed on both sides of the board, makes it even easier to do.

But, great... new caps, but the monitor's still dead.

I've checked the flow chart and tested the transistor, not shorted to the chassis.

The flow chart then says to check X601. That diode was good, but I checked the other ones while I was down there. X602 and X603 were both shorted inside... Sound like my culprit(s)? I've removed both of them fro the circuit and did a diode check on them, "beeped" both ways on both and "0.00" across the board on both.

So I guess I need to start shot gunning the thing starting with, those 2 guys (might as well replace all 4 while I'm at it)... The manual for the monitor lists them as RM-2A V 600V. What would be good replacement parts for them... and if there's any way to get them from Mouser.com that would be outstanding... I'm just not 100% sure what I should be looking for as far as "stats" for the replacements.

[Scucci]

Okay, after a little more looking, I think I found the part?

Will this guy work to replace a RM-2A V 600V (according to the monitor manual)?

http://mouser.com/Search/ProductDetail.aspx?R=STTH2R06RLvirtualkey51120000virtualkey511-STTH2R06-TR

[Ken Layton]

RM-2AV crosses to an NTE125 or 1N4007

[Scucci]

Ken!

Thank you... I've been try'ng to get an answer to that question on atleast 3 different forums and no one has helped. 

Are you have'ng any luck with getting back on KLOV?

EDIT: I checked both of those on mouser, they're showing 1000V peak reverse and 700V RMS reverse... The ones that I'm replace'ng are 600V... Is that going to be an issue or should it be okay since they're just rectifiers and are just setting up the juice for the rest of the chassis?

[Kevin Mullins]

Maybe:

http://www.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMtGzcFJCuAvkaIuEuNS1Mmc

http://www.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMtGzcFJCuAvkUfVc%2f3gAguo

http://www.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMtqO%252bWUGLBzeMREKq5JnfV%252b

[Scucci]

Yeah, I looked through all of those... I was try'ng to find an exact match for the ones I'm replace'ng.

I don't think they'll make too big of a difference considering what their job is... but I just get really paranoid about this kind of stuff since I have 2 monitors and 2 chassis... and 1 of each of those is in Tron, and the other is what I'm working on. I don't have any spare parts laying around I can swap out incase I make a boo-boo and I don't have the money to buy new ones or send the old ones off for repair if I fry the whole shebang.

[Ken Layton]

According to the cross reference, the 1000 volt rating is fine in your application. It's just a better specification than the original.

[Scucci]

Thanks again, Ken. I kinda figured as much because they're not actually doing anything but providing DC to what needs it... but again, just paranoid. Thanks, I'll get the mouser order put in ASAP... REALLY need to now since my crystal broke off of my Robotron soundboard... So I have to get that replaced too. Glad I delayed on getting the order put in... I'd hate to pay the shipping again on just a crystal. ... ... <rant> Which wouldn't be so bad if they'd friggin' use padded envelopes or something, it's retarded to order in 4 diodes and have to pay 5 bucks shipping... shouldn't cost anymore than a $1 or so to send them... </rant>

[qrz]

just a comment on gen purpose diode piv ratings.
in tv repair (usa) , i use a 400 piv rating for line rectification.  suggest  600piv for 220v
 i like the 400v rating best due to it being the most likely item to fail with a pwr line surge or spike.
i.e. the diode(s) short , blowing the line fuse and likely protecting the equipment. ( doesn't get beyond the
input of the pwr supply )

the 1kv piv rating will tend to pass transients via junction capacitance , and the higher piv rating makes them less
likely to fail at levels that may damage additional circuitry.

qrz

[Scucci]

I replaced them with some 600V I found at, of all places, RadioShack... go figure, they actually HAD something useful beside 20g wire.

Replaced all the diodes in the bridge and she fired right back up.

Thanks for all the help everyone.

EDIT: No, really... RadioShack sucks. I needed 20g wire... they had it. I needed a 3.58MHz crystal... the MOST COMMON crystal in the friggin' world... and they didn't have it... didn't have any crystals. But, they did have 2 packs of 2 diodes that I needed... just enough to replace the bridge... Go figure. RadioShack is less like a parts store, and more like a yard sale of components... you never know what you're going to get from day to day... sometimes it's priceless art or good vintage comic books... sometimes is just table after table of used baby diapers.