Comet repair job

[shardian]

Yeah my problem with the touchup is the location. It's where there is the crowd of people so it's very detailed....

The treasure cove product would remove that cloudy effect on mylar then?

If you mean the overall dullness of it, yes. If there are small areas where the mylar is lifted and the 'cloud' is under the mylar, then no. Nothing will ever remove that.

 

[Schusler]

No nothing is lifted. The pin in question is TX Sector. It has a big piece of mylar the is centered above the flippers. I tried Clay's method of using some wet/dy sandpaper but really didn't notice a difference.

Well cool, I'll try that product-I guess it nullifies my plan of just removing it

 

[shardian]

No nothing is lifted. The pin in question is TX Sector. It has a big piece of mylar the is centered above the flippers. I tried Clay's method of using some wet/dy sandpaper but really didn't notice a difference.

Well cool, I'll try that product-I guess it nullifies my plan of just removing it

It makes a huge difference in the appearance of the Mylar. The video on their site where they do a Batman forever is exactly how it turns out if you go for a high gloss finish. Your gut feeling when you see that video is that it worked for them, but wouldn't work for you. That's what I thought when I initially saw it. You have to have a corded 3000rpm drill though. A cordless only goes 600-900 rpm and is absolutely worthless.

 

[Tim N.]

No nothing is lifted. The pin in question is TX Sector. It has a big piece of mylar the is centered above the flippers. I tried Clay's method of using some wet/dy sandpaper but really didn't notice a difference.

Well cool, I'll try that product-I guess it nullifies my plan of just removing it

On that DE Batman I had, I polished the mylar by hand, but started with 800 grit sandpaper and worked my way up to 1500 grit using Novus 2. It came out looking like day one mylar. I use the same apprach on deeper scratches on DMD covers as well....(Flame polishing a DMD cover doesn't go so well)...

The TC kit is nice for sure, but I often don't like to use a drill anywhere near my PFs when I don't have to..... Just a little too random for my liking (not that I have had an issue with it)....

 

[shardian]

On that DE Batman I had, I polished the mylar by hand, but started with 800 grit sandpaper and worked my way up to 1500 grit using Novus 2. It came out looking like day one mylar. I use the same apprach on deeper scratches on DMD covers as well....(Flame polishing a DMD cover doesn't go so well)...

The TC kit is nice for sure, but I often don't like to use a drill anywhere near my PFs when I don't have to..... Just a little too random for my liking (not that I have had an issue with it)....

I don't even want to know how long that took you!

 

[Tim N.]

I don't even want to know how long that took you!

LOL.... it wasn't that bad.... Maybe two hours total?

Not nearly as bad as pulling mylar, touching up, and clearing.....

I had a Pinbot that I pulled mylar on (and didn't clear), and pulling the mylar took about 20 minutes with a heat gun (no major paint loss), but getting the adhesive off took about two weeks (or so it seemed).... System 11s suck for pulling mylar....


The nice thing about the Batman was I didn't even have a choice, if I had pulled mylar, it would have taken the whole PF paint with it, as it was the only thing holding the paint on the PF was the mylar.... That early "Stealth Coat" DE experimented with was absolutely horrible.

 

[shardian]

LOL.... it wasn't that bad.... Maybe two hours total?

No way. There is just no way you worked from 800 to 1500 with multiple passes of each grade and a final polish in 2 hours. Do you have a bionic arm or something?

 

[Tim N.]

No way. There is just no way you worked from 800 to 1500 with multiple passes of each grade and a final polish in 2 hours. Do you have a bionic arm or something?

Well, one arm for some reason is stronger than the other, LOL.....But that is a different topic......

Honestly, It was probably closer to 90 minutes than 2 hours, but I don't remember exactly. Mylar is pretty soft stuff. I used a hand block sander, worked thoroughly with the 800 to really get it roughed up and cleaned good, and then took 1000 to it to remove the deeper scratches, and then the 1500 to make it completely smooth.

Working in straight lines as opposed to orbital (I personally believe) is the key to the whole thing when using sandpaper and polish.

As far as the DMD cover, it actually took longer and I had to use an orbital buffer, as the plastic is much harder than mylar....

Some pics are attached just for reference.... It is pretty easy to see where the "stealth Coat" is, and where the mylar is.....

I always was a fan of the location of the up post between the flippers on this one

 

[Tim N.]

Well, one arm for some reason is stronger than the other, LOL.....But that is a different topic......

Honestly, It was probably closer to 90 minutes than 2 hours, but I don't remember exactly. Mylar is pretty soft stuff. I used a hand block sander, worked thoroughly with the 800 to really get it roughed up and cleaned good, and then took 1000 to it to remove the deeper scratches, and then the 1500 to make it completely smooth.

Working in straight lines as opposed to orbital (I personally believe) is the key to the whole thing when using sandpaper and polish.

As far as the DMD cover, it actually took longer and I had to use an orbital buffer, as the plastic is much harder than mylar....

Some pics are attached just for reference.... It is pretty easy to see where the "stealth Coat" is, and where the mylar is.....

I always was a fan of the location of the up post between the flippers on this one

Also, forgot to add, any lines you see on the polished mylar is actually from under the playfield from the inserts.... Did I mention the paint/finish on these generation DE's sucked?

 

[Schusler]

On that DE Batman I had, I polished the mylar by hand, but started with 800 grit sandpaper and worked my way up to 1500 grit using Novus 2. It came out looking like day one mylar. I use the same apprach on deeper scratches on DMD covers as well....(Flame polishing a DMD cover doesn't go so well)...

The TC kit is nice for sure, but I often don't like to use a drill anywhere near my PFs when I don't have to..... Just a little too random for my liking (not that I have had an issue with it)....

Tim that was the Batman I was going to get from you... From your pics that machine looked beauuuutiful!

 

[Tim N.]

Tim that was the Batman I was going to get from you... From your pics that machine looked beauuuutiful!

The one and the same

You can only do so much when polishing a turd (In this case literally, LOL)....

Sorry to sidetrack your Comet post Shardian.... At least it is bumped to the top.....


To bring it full circle, have you replaced the sound rom on the Comet? If not, I could send you another one if you think it would help.

 

[Schusler]

The one and the same

You can only do so much when polishing a turd (In this case literally, LOL)....

Sorry to sidetrack your Comet post Shardian.... At least it is bumped to the top.....


To bring it full circle, have you replaced the sound rom on the Comet? If not, I could send you another one if you think it would help.

I have to say that you had the best Batman I've seen. That had one at expo last year and wow that thing was beat to hell. I may also add I believe he wanted around 2k for his



I don't want to hijack your thread either Shar but I also have a minor issue with my Comet. I believe it is either f2 or f3 fuse keeps blowing. Checked all coils nothing locked on. I believe it has to do with the backbox flashers cuz only 1 out of 4 work. You think I might have a short in one of the sockets?

 

[Tim N.]

Okay, here is another problem I found - the speech is messed up. I posted this over at RGP and have gotten nothing so far. Here it is copy/paste style:

I am working on a Comet with a Speech issue. I'll summarize what it
has done so far:

-Initially, there was sound present during speech, but it was super
garbled. I reseated the speech roms and the CPU sound rom. At this
point about half the speech sounds were audible, but very faint.
- I pulled the speech board for inspection. U3's legs looked pretty
cruddy, so I reflowed the solder on it. Upon reinstalling the board, I
had all speech when the speech swtich was pressed on the CPU. I
started a game and the speech worked for about a minute. Nothing I did
made it better.
-The next day I came back to it, and completely resoldered U2 and U3,
including making sure the 2 top-side trace connected legs had good
connection. Plugged it back in and speech worked again. I played a
whole game just fine. Came back in the morning to see if it played
cold. It did not- speech was gone.
- Since heat seemed to have something to do with it, I used a heat gun
to warm up U3. After turning the game on, only garbled static came
out. during speech test.
- At this point I suspected U3 was bad. It was the only thing I was
messing with and it brought full functionality back. I ordered the
amps and caps since I would have it out anyways. I started by only
replacing U3. Put it in a everything worked same as the last two times
I messed with U3. After about five minutes, it was all gone again. I
proceeded to replace U2 and all caps but the polystyrenes. Now I have
nothing at all.

At this point, I assume U1 is bad. Figured I'd post here though and
see if anyone had any ideas as to why this is so oddly intermittent
and works after I resolder U3??

One last note: The explosion sound that comes last in the speech test
is always there and plays perfect. It's produced by the cpu sound
circuit though. All other standard sound in the game works fine.

Any ideas? Something is intermittent for sure. Maybe a cracked trace??

I finally looked at the manual online....

What sounds do you have working?

Explosion?- CPU controlled- You said-works
I would assume that:
Million- works
2nd laugh- works
Splash- works

What about:
Turkey?
CMon get me?
Hey?
Train Whistle?
Ahhhh?
1st laugh?
Roller Coaster?

 

[Tim N.]

I have to say that you had the best Batman I've seen. That had one at expo last year and wow that thing was beat to hell. I may also add I believe he wanted around 2k for his



I don't want to hijack your thread either Shar but I also have a minor issue with my Comet. I believe it is either f2 or f3 fuse keeps blowing. Checked all coils nothing locked on. I believe it has to do with the backbox flashers cuz only 1 out of 4 work. You think I might have a short in one of the sockets?

F3 is lamps, F2 is solenoids... Do you know which one specifically?

 

[Schusler]

F3 is lamps, F2 is solenoids... Do you know which one specifically?

F2 for sure...

 

[Tim N.]

F2 for sure...

Have you tested all the transistors yet with a DMM?

The online schematics are pretty tough to see, but what if you pull from (IJ4?) and (IJ19?) from the CPU board and fire it up, does it blow a fuse?

 

[shardian]

I finally looked at the manual online....

What sounds do you have working?

Explosion?- CPU controlled- You said-works
I would assume that:
Million- works
2nd laugh- works
Splash- works

What about:
Turkey?
CMon get me?
Hey?
Train Whistle?
Ahhhh?
1st laugh?
Roller Coaster?

Right now, only the last sound (explosion works) I've seen this posted on RGP before, but it was a dead thread too. Explosion isn't even on the Speech board because it still shows up when you turn the speech board pot all the way to CPU sound only.

I have had all speech working 3 times now after using an iron on the U3 1458 amp chip. I assume that means all roms are fine.

I have also continuity tested all traces and plated through holes. Everything checks out. I replaced both sound amp chips and all caps but the poly caps. The only thing left that can really be the problem is U1. What I need is a way to test that chip...and then a supplier that sells it.

 

[shardian]

F2 for sure...

First off, you need to test all the transistors on the CPU for shorts. Then you need to check the resistance of all the coils in the game. 4-5 ohms should be on every coil. Less than three is a short. Then you need to make sure the skirt of one of the pop bumpers aren't getting stuck. That was the cause of all the damage on this game. Honestly, on a game with this kind of special coil circuitry you really should go ahead and replace the pop bumper wear pieces( body and skirt).

You will find your problem with one of those checks.

 

[Tim N.]

Right now, only the last sound (explosion works) I've seen this posted on RGP before, but it was a dead thread too. Explosion isn't even on the Speech board because it still shows up when you turn the speech board pot all the way to CPU sound only.

I have had all speech working 3 times now after using an iron on the U3 1458 amp chip. I assume that means all roms are fine.

I have also continuity tested all traces and plated through holes. Everything checks out. I replaced both sound amp chips and all caps but the poly caps. The only thing left that can really be the problem is U1. What I need is a way to test that chip...and then a supplier that sells it.

Take a gander here- http://groups.google.com/group/rec....rm/thread/4dcf2943974141e?tvc=1&q=comet+sound

 

[shardian]

Take a gander here- http://groups.google.com/group/rec....rm/thread/4dcf2943974141e?tvc=1&q=comet+sound

I've read that thread before, and that was the info I was looking for about testing. I forgot where I read it - thanks! Kind of moot though, because I have replaced U3. The only thing left that could be wrong is U1. I would just like to know the logic behind why I was able to probe U3 with a soldering iron three times and get the board to work for a while. That is weird, considering U3 apparently wasn't the problem. Either way, I will check for pulsing on those pins.

U1 is a "55536 continuously variable slope delta modulator". Anyone have one of those lying around?