Bringing an EDOT to life....

[jonathan1138]

Ok. Been at this all day. Here is exactly where i am at.

I can actually play the game now! Lights work, everything seems to be in working order. What a game, exactly as i remember it (played it as an 8 year old).

BUT, Fuse F4 still blows and runs very hot - after 10 - 15 minutes. Its a 5 amp slo blo (what the cab calls for). When i got the cab, there was a 7 1/2 amp fuse in there, so i am guessing the cab had this issue for awhile (although the game hasnt been running in 15 + years).

CDJump suggested that along the way there may have been a service bulli to put that fuse in, but still not sure.

I have isolated the issue to the main PCB though. If i have EVERYTHING plugged in, except for J1 to the PCB, the fuse runs cold. If i plug in J1, the fuse runs hot. If I disconnect everything (including all other PCB connections, to coin door and CP for example), and just put J1 in, the fuse runs hot.

So, something going on with the PCB. Keep in mind CDJump had the PCB last week with the power supply, working 100 percent.

Strange.... I am over here spinning my wheels, so any help is REALLY appreciated! So close to reviving it completely.

 

[ELutz]

F4 fuses one side of the 8VAC center tap off the transformer. The voltage goes through one of those big diodes and the 100,000uf cap to become unregulated DC voltage.....then on to the power supply board.

I'm pretty sure a service bulletin was issued to up that fuse to a 6 amp slo-blo. I'll double check and see if I can find it.

It might be your transformer. I've had a couple bad one in MCR games over the years. I had one in a Tapper......after it was on for awhile.....it would just shut down. No fuses blowing.....it would just stop putting out juice. Let it cool down for a bit, and it would power back up. That one drove me crazy for awhile. Finally, after ruling everything else out....I swapped the transformer and the problem went away. The other one was in a Solar Fox. It would pop the fuse after 10-20 minutes. I don't remember which fuse it was, but after ruling everything out.......I figured it had to be that transformer. To confirm my suspicions.....I jumpered the fuse clip with a 15 amp breaker. Well, after about 30 minutes the transformer started smoking. I replaced the transformer and all was good.

Edward

 

[jonathan1138]

Elutz,

Thanks. I was actually looking at that rusty old transformer today and wondering why those things never seem to die!

The latest - popped a 6 1/4 amp fuse in there. Game ran great for a half an hour before i pulled the plug. Nice. BUT, the fuse runs very hot. CD Jump still suggest a 7 amp fuse, which i think i'm gonna do.

I just don't get why F4 / that fuse is running so hot. I may just place an order to BR this week for a fuse holder to cut out any resistance, but i measured, its not bad at all.

I may also install a small fan down there, unless someone can help understand why / how to correct the heat issue... is it normal for a fuse to get that hot?

I will post pics this weekend of the game.

 

[ELutz]

It's very uncommon for a transformer to have issues, but it does happen. I've seen (maybe) four in my repair experience......and a couple of those looked as if they'd been under water for awhile.

No, a fuse should not run hot......barely warm at ambient temparatures....at worst.

Edward

 

[jonathan1138]

This cab is strange. The Transformer looks like it took on some water, yet, the entire cab shows no sign of water damage.

CDJump suggest a new Fuse holder (BarakaWins also suggested that yesterday).. going to RS hoping they have something i can work with.

 

[joeyoravec]

It might be your transformer. I've had a couple bad one in MCR games over the years. I had one in a Tapper......after it was on for awhile.....it would just shut down. No fuses blowing.....it would just stop putting out juice.

Makes sense. And in this case perhaps he's pulling all the juice from a single leg of the center-tapped transformer. Hookup 2 multimeters and measure current. When the fault happens 10 minutes later see if there's current flowing across the F3 leg. Maybe it won't be because the transformer is failing? Worth a try.

 

[jonathan1138]

Guys,

I replaced the fuse holder - still runs hot. I notice that F3 (the one next to F4 ) is also running hot.

CDJump explained to me how to check for a short on the PCB - sorry, i didnt understand how before. Just checked that - PCB not connected to anything, set to Ohms, red lead on Pos of Filter cap, black on negative - getting ticking numbers up to .338 or so.... sounds like i have a short?

How do i find it now!

 

[joeyoravec]

Apply a 30amp power supply. Run it for an hour. Replace whatever catches fire.

Did you mean 338 ohms or 0.338 ohms? Helps if you can isolate it to one of the 3 boards. repeat the measurement separately for each one. Sure didnt seem like a short to me, sounds more like a transformer whose F3 winding opens after about 10 minutes.

 

[jonathan1138]

Joey,

To clarify the behavior - without J1 plugged in (main PCB connector)- and everything else in the cab hooked up - everything is smooth. Voltage is perfect, etc, for a half hour+.

If i hook up J1 (which plays the game of course), Fuse F4 gets really hot immediately. With a 6 amp fuse in there, i can have the game running for 1/2 hour, maybe more if i get brave. But for now, the game is running perfectly including lights, etc, with exception to that fuse being hot only when J1 is in. So, good news is i can play EDOT!

In reverse - If i disconnect everything, all other PCBs - and Only have J1 in, same results. Hot F4.

CDJump, who had the boards recently (working with no issue, which puzzles us more!), asked me to run the PCB short test (as did MJenison) - My steps - i isolated the board, ohm test across the filter cap, getting .338. Now, i am new to this, maybe i screwed that up, i will do that a few more times.

Yeah, its best to now isolate it to one board on the stack.... CDJump kindly offered to take it back (if its shorted as i read of course), but i would love to nail it down this weekend.

 

[jonathan1138]

Getting .353 steady on the filter caps. Not sure if thats a short on the board or not....

 

[joeyoravec]

...but again. what units? kOhms or Ohms?

 

[jonathan1138]

Joey - just checked...

.353k

 

[joeyoravec]

I'll measure some of my MCRs later for you, but 353 ohms doesn't sound (at all) like a short to me. I'd suspect faulty transformer like I suggested earlier.

 

[jonathan1138]

Joey,

No need to check. CDJump has checked already, just awaiting word on my readouts from him.

Oh well, if its not a short, I will start shopping for a new Transformer soon.....

 

[jonathan1138]

The latest - on the advice of Joey and CDJump - measured amperage at F4 / F5. Getting a steady 2.5. Also note CDJump says there is no short.

The fuses run hot, i will just keep watch on them. Right now, i have 6 amp slos in there.


So, i think its safe to say this EDOT is alive!

I am really grateful for the advice dished out here. I learned alot with this one.

 

[jonathan1138]

Guys,

Ran the game for an hour (getting brave!). Runs fine, stable. The F4 / 5 fuses are still hot. I am focusing more attention on that transformer. It runs hot too. Not enough where i recoil, maybe its 10 degrees more than anything else. I also notice that after the cab is off for 5 minutes, the two fuses cool off quick, but the xformer is still hot.

If this is abnormal, let me know. Also, Elutz or Joey - can you advise on the proper transformer to order (Bob or Mouser - prefer Bob, he is great). I will order one and mark down another one saved. Thanks alot guys.

Thanks.

 

[jonathan1138]

To put this into perspective - i have a thermal gun - after a half an hour, the PS is pegged around 80 degrees while the power chassis / F3 - F4 and Transformer are running at 120 degrees or so. Seems abnormal right?

I just asked Bob if he carries a replacement transformer. Hopefully thats it. CDJump also suggested i put new connectors on the fuse holder, which i will do as well.

 

[ELutz]

Getting .353 steady on the filter caps. Not sure if thats a short on the board or not....

Are you sure this reading isn't .353K.....???
...because, at .353....you'd be blowing a fuse....almost immediately.

Do you have any other MCR hardware games (Tron, Satan's Hollow, Tapper, etc.)?

Edward

EDIT: Sorry.....just realized their was another page.....Disregard above.

 

[jonathan1138]

Elutz,

Yeah alot going on / i am posting a play by play (using this like a Journal i guess).

The latest is that this is definitely a resistance problem. Just dont know where.

Very interesting read. This is a forum posting about someone running with a Hot Fuse box (like me!)......

http://www.terrylove.com/forums/showthread.php?16991-Hot-fuse-box

Outcome from what i read:

The more resistance the less amperage as shown here
E=IXR
120 volts divided by 10 ohms equals 12 amps
120 volts divided by 100 ohms equals 1.2 amps
It is clear that when the resistance is increased the amperage drops.



Note my amp readings on my EDOT at F3 / F4. 2.5.

CDJump, on a Spyhunter was reading close to 4 amps on both F3/ F4. Well, 2.5 amp current on both spots on mine is not right. Now i need to track down where the resistance is. I will start with the connectors to the fuse holders.

Question - would ANY bad wiring in the cab - such as speakers, service switches, etc cause resistance that would impact these two fuse slots?

Besides continuity checks with resistance measures at every point, would these bad points maybe generate excessive heat that i could track down with a thermal gun?

 

[ELutz]

The latest - on the advice of Joey and CDJump - measured amperage at F4 / F5. Getting a steady 2.5. Also note CDJump says there is no short.

The fuses run hot, i will just keep watch on them. Right now, i have 6 amp slos in there.


So, i think its safe to say this EDOT is alive!

I am really grateful for the advice dished out here. I learned alot with this one.

If the entire system is pulling 2.5 amps.....there's no way the motherboard (that I can see) stack could be the cause of a 5 amp fuse blowing.....and the same....2.5 amps shouldn't make those fuses hot.

Edward