Just Re-capped a DK Jr. Monitor...question...

[sk8ersublime]

A monitor by itself will power up without a game attached, but you might not see anything on the screen if the brightness is properly set. You should see the heater element in the tube's neck glow, and if you adjust the brightness all the way up, you should see a raster pattern on the monitor.

An isolation transformer is not required for a monitor plugged in by itself (without a game), simply to see if it works. However, risk of shock is increased, and you should never use a monitor without an isolation transformer with a game or with any test equipment!

Any ideas why mine would not? I replaced all of the caps with the DK jr. Plus kit from Arcadeshop.com There was one that i noticed was different than the old one tho.

the old one was "33uf @ 160V" they had me replace it with "100uf @ 160V" would a cap or maybe a broken trace to a cap cause this thing not to fire up? I mean, i would expect if the cap was wrong or a bad trace, there would be some smoke or something.

 

[Technopope]

Any ideas why mine would not? I replaced all of the caps with the DK jr. Plus kit from Arcadeshop.com There was one that i noticed was different than the old one tho.

the old one was "33uf @ 160V" they had me replace it with "100uf @ 160V" would a cap or maybe a broken trace to a cap cause this thing not to fire up? I mean, i would expect if the cap was wrong or a bad trace, there would be some smoke or something.

There is usually a pretty wide tolerance with electrolytic caps, both in circuit design and the cap itself. (The parts themselves are usually only within 20% of the stated value.) The difference of the part you mentioned is a lot, but probably not much of a concern.

You should make sure that the parts were put in the right way though. Most are probably polarized, with a + and - lead. Putting one in backwards could cause the monitor to not work. There might not be any visible sign if you powered the monitor up for a short time with one installed backward, and probably no damage done. Definitely something to check.

 

[CrazyKongFan]

Yeah, I know Bob's is overkill, but it described how and why you need to do it, which I figured was a good thing for someone who hasn't done it before I pretty much did the same thing as you guys, just took some wire, wrapped it a few times around the screwdriver and taped it, and attached an alligator clip to the other end of the wire.

 

[sk8ersublime]

There is usually a pretty wide tolerance with electrolytic caps, both in circuit design and the cap itself. (The parts themselves are usually only within 20% of the stated value.) The difference of the part you mentioned is a lot, but probably not much of a concern.

You should make sure that the parts were put in the right way though. Most are probably polarized, with a + and - lead. Putting one in backwards could cause the monitor to not work. There might not be any visible sign if you powered the monitor up for a short time with one installed backward, and probably no damage done. Definitely something to check.

ill check again, but I took my time when installing everything so I am pretty sure everything was done right.

 

[ballytablewiz]

Your recap is not the source of your problems - plugging the Sanyo directly into the wall most certainly is. As has been stated, you fried many components on the monitor chassis, whether visually evident or not. This is a unsettlingly common occurrence and searching the forums will give you plenty of insight into the situation. Unfortunately for you, I've never seen a thread on this end with a fixed monitor. Countless hours are spent trying to find and replace components, only to have the monitor never work again. Feeding 120v to a Sanyo is a disaster, and beating around the bush looking at other causes is going to get you nowhere. Not to bring you down, but your pooch has been officially screwed.

 

[Michael Roma]

I could have sworn that I read a post a while ago where someone plugged a Sanyo in the wall outlet and it actually worked for a little while (perhaps and hour or so). I would def not keep it plugged in or plug it in anymore to the wall.

As others have stated... pull the chassis board and inspect that you have the polarity the right way on all the caps you replaced. While it is out, check the fuses with a DMM. Once done, put it back in your cab and test properly.

- Mike

 

[JamBurglar]

Your recap is not the source of your problems - plugging the Sanyo directly into the wall most certainly is. As has been stated, you fried many components on the monitor chassis, whether visually evident or not. This is a unsettlingly common occurrence and searching the forums will give you plenty of insight into the situation. Unfortunately for you, I've never seen a thread on this end with a fixed monitor. Countless hours are spent trying to find and replace components, only to have the monitor never work again. Feeding 120v to a Sanyo is a disaster, and beating around the bush looking at other causes is going to get you nowhere. Not to bring you down, but your pooch has been officially screwed.

He's right, this is a common occurrence and it's exactly what you see in many of these threads. I don't think I've seen one yet where the person has been able to fix the damage (although its possible they fix it and never update). You definately need to search the forum though. Tons of people have done this.

 

[sk8ersublime]

!!!!!!

I fixed it Honestly I think plugging it in to a wall should be fine the board is labeled 125v the wall is 120v.... sorry for being stubborn.

But i checked my connections and I had a few caps that broke the traces on the board i think this happened when i clipped the ends off...so I did some trace repair, put that 1 33uf cap back on, and BAM! power to the tube! Everything seems ok for now, but i unplugged it right away...lol

 

[sk8ersublime]

Well before i get ahead of myself...its now powering, and i hear it working, but the screen isnt bright even with turning up

 

[cwales]

why does this always happen to DK Jr? This is the third one within a few months, mine included.

 

[LyonsArcade]

Man... I don't know how many times somebody has to explain it to you.

DONT PLUG THE FUCKING MONITOR INTO THE WALL, THEN ASK US WHY IT ISN'T WORKING RIGHT.

Hope that cleared it up a little bit for you.

 

[FrizzleFried]

I have a Sanyo that ran at 120v without issue for months or even longer... strange as it may seem. A Nintendo ISO is rated at 100v but it actually outputs like 109v... so the jump from 109v to 120v isn't necessarily a 100% kill...

That said, you DID run it out of spec and I am sure SOME boards could/would be affected...

 

[LyonsArcade]

It's not the 120, it's the isolation transformer. Running a monitor without an ISO can fuck up all kinds of stuff, like for instance, the guy who started this post's monitor.

 

[gregatron]

I think he's thinking that since the "label " on the board says 125V it's cool. Sanyos are 100V monitors, like most stuff from Japan was/is. The "label" you see is the fuse rating "125V @ 4A" that does not mean the chassis can take 120VAC unisolated.
As some have said, it may work for a bit running 120V but I guarantee it's not designed to.
Just test it with the right voltage and go from there. If it doesn't work check your rectifying diodes, voltage regulator, and related components.

 

[sk8ersublime]

Man... I don't know how many times somebody has to explain it to you.

DONT PLUG THE FUCKING MONITOR INTO THE WALL, THEN ASK US WHY IT ISN'T WORKING RIGHT.

Hope that cleared it up a little bit for you.

Thank you for your kind words

jackass...

anyway...Im not asking why its not working anymore, I was just updating that I got the monitor to power up. I believe it had to do with the broken trace/ wrong cap. It is unplugged and I have discharged it and will not be messing with it until i get the 100v ISO from the cab this weekend.

 

[sk8ersublime]

I think he's thinking that since the "label " on the board says 125V it's cool. Sanyos are 100V monitors, like most stuff from Japan was/is. The "label" you see is the fuse rating "125V @ 4A" that does not mean the chassis can take 120VAC unisolated.
As some have said, it may work for a bit running 120V but I guarantee it's not designed to.
Just test it with the right voltage and go from there. If it doesn't work check your rectifying diodes, voltage regulator, and related components.

Yea i actually thought about that and realized that is just for the fuse. I am not running it on the wall. Waiting for the weekend to get the ISO