VND acting up

[LLUncoolJ]

Pretty sure Flake is a walking EMP. He came over and turned on Viper Night Drivin and it promptly began to reset itself everytime he pressed both flippers at the same time. Then he left and it acted right for awhile. Now it is just resetting itself whenever the mood strikes. Since it started, it has been an intermittent problem. This is a Sega machine, anything y'all can think of off the top of your heads?

[lilshawn]

the +5 might be flaking out. try replacing the rectifier bridge and the cap for the 5 volt.

[LLUncoolJ]

uhhhhh....English? 

[LLUncoolJ]

I turned the machine on this weekend and got a new and crappy development. No DMD, no sound, no response to the start button. All ligts come on and are working. When I say no sound, you can hear the thump when you first turn the power on, just no music. And the DMD does blink once, just doesn't display anything. 

[LLUncoolJ]

The backglass lights and the playfield lights all came on like they normally would. All of the lights that would normally come on when you power up.

[LLUncoolJ]

I do believe they were, buy I've had about 40 beers since. Let me check it again tonight.

Feature lights, bonehead, what are those doing?  These are the inserts that light up and flash and put on a show for you.

You'd better watch it or I'm not gonna stick up for you anymore.

EDIT:   If they are lit, then what? Trying to save a step here.

[LLUncoolJ]

Thanks PBJ, I'll check into it. I got busy last night working in the garage and forgot to fire up the pinball. I'll tie a string around my finger to remember tonigt.

[shardian]

There's no magic answer in pins. You have to check voltages/fuses before we can tell you anything else. And yes, you power supply voltages are off/missing from the way you have described it- specifically +5 for logic. No/low +5 = no boot up, no DMD.

[JeepMonkey]

FWIW, I saw a pinball repairman working on a Simpsons that would reset when both flippers were hit and he was looking at the rectifier as the cause.

[LLUncoolJ]

Fired it up last night to see what the lights were doing and of course it is working...sound, lights, DMD. But start to play and it resets. Started a game...fine, hit both flippers at once....reset. Then it reset again about a minute later by itself.

[LLUncoolJ]

No offense, but you're borderline impossible to help.

I hate you. I really do.

[lilshawn]

 

the 5 volt runs EVERYTHING computerized on the machine, if the 5 volt is low or the flaking out stuff won't even start up. Should be 4.92 to 5.1 volts DC. If this is below 4.92 volts, the game will most certainly reset easily, as this is the voltage the "reset watchdog" examines. Often the problem is bridge rectifier  measure it from various places and see if it is 5 volts. if it's low or zero try replacing the rectifier bridge and the cap for the 5 volt line.

a detailed explanation of how to do that is available at pinrepair.com

[LLUncoolJ]

Alright, according to the manual, BRDG 21 (yellow arrow) is the 5 volt bridge rectifier and C203 (green arrow) is the capacitor. Where do I measure the voltage? Keep in mind, I am an extreme novice...do I put a lead on a ground, the other on some point in the pic?

I tried removing and inspecting the connections, same results...unfortunately...I was hoping for the easy fix.

[studmuff]

Alright, according to the manual, BRDG 21 (yellow arrow) is the 5 volt bridge rectifier and C203 (green arrow) is the capacitor. Where do I measure the voltage? Keep in mind, I am an extreme novice...do I put a lead on a ground, the other on some point in the pic?

I tried removing and inspecting the connections, same results...unfortunately...I was hoping for the easy fix.

Hi,

There really isn't a quick fix.  But it can probably be an easy fix.  I recommend you check out this website and this page:

http://www.pinrepair.com/de/index2.htm#reset

If it's over your head and you don't understand it try to find someone who is a pinhead in your area that can help via Mr Pinball Classifieds or maybe the pinball newsgroup.  If you have basic knowledge of pinballs and feel comfortable removing boards and working on them (desoldering and resoldering new parts, you will be ok.  My guess is it is either the 5 volt capacitor going bad or one of the bridge Rectifiers.  With out the pinrepair guide most of us would be lost.  Hope this helps you.

[LLUncoolJ]

There really isn't a quick fix.  But it can probably be an easy fix.  I recommend you check out this website and this page:

http://www.pinrepair.com/de/index2.htm#reset

If it's over your head and you don't understand it try to find someone who is a pinhead in your area that can help via Mr Pinball Classifieds or maybe the pinball newsgroup.  If you have basic knowledge of pinballs and feel comfortable removing boards and working on them (desoldering and resoldering new parts, you will be ok.  My guess is it is either the 5 volt capacitor going bad or one of the bridge Rectifiers.  With out the pinrepair guide most of us would be lost.  Hope this helps you.

I looked at this last night. Going by what the guide says, I have to agree that the 5 volt capacitor is the culprit. The symptoms all point to it, specifically the resetting when both flippers are pushed. I think I am up to at least trying to replace it, it doesn't look too daunting. If that fails, I may go the PBJ route and call in the cavalry. Is the capacitor something I can find locally at a Radio Shack or will I have to order it in?

Thanks for the help guys.

[LLUncoolJ]

This guy know anything about pinball...so that he can catch any obvious ---fudgesicle--- ups I make while ordering? I'm basically at the mercy of the numbers I find on the original parts.

Being a novice, I think other novices would be well advised to stay away from the more obscure titles. There just isn't much help out there. The pinball repair page was for titles up to 1995. This one is a 1999 and nothing looks the same as his pictures and descriptions. Not to mention, this one is such a short run (1100), that parts are non existant. Try finding glo-balls...and bring your American Express if you do find them. BTW, I have 3 spare balls for sale. 

[lilshawn]

yah being newer is a little difficult to diagnose, since people havent had much of a chance to fix them yet.

[studmuff]

I still say this has nothing to do with the capacitors, but whatever.  Maybe when you replace them all, you'll knock enough crud off the connectors to get good contact.   

You could be right.  All though it could really be about 20 different things.  Could be connectors loose, wire losse, cold solder joint anywhere on the capitors, rectifers, connector header pins, a flaky diode, etc, etc.  For all we know there could be acid dripping batteries in the cpu.

[LLUncoolJ]

So is the concensus that I have a +5 Volt problem? Seems like most of you think that is a place to start. I am going to start with the PBJ idea of a cruddy connection. I'll inspect and try to clean the connections on the I/O power board. See if that does anything. I didn't notice anything with the batteries, but what the hell, I'll pull them out and replace them. Since the capacitors seem like a fairly easy solder job, I'll move onto that next if need be. After that, unless I get more suggestions, it looks like I'll have to call in the cavalry.

We had my kid's baseball team party at our house over the weekend and one of the parents used to service pinballs. He got all spanky and wanted to find a board from another machine and reprogram it. I think that is putting the cart before the horse myself, I don't think the board is fried by any stretch. Needless to say, I'm not sure the dude is trustworthy.

PBJ, please change back to the fat cat avitar...is nothing sacred?

[Q*Bert_OP]

I assume you have a digital volt meter...anyways, in DC mode, place the red probe on the +5vdc test point, and the black lead under a ground strap...get close to +5v? Now place the meter on the AC setting...see any significant voltage? If you see more than...say .2vac, you have a capacitor problem...if not, change out the +5v rectifier, I have fixed 3 late model Sega driver boards with failed rectifiers in the past year...this problem seems to be quite common these days...

[LLUncoolJ]

I assume you have a digital volt meter...anyways, in DC mode, place the red probe on the +5vdc test point, and the black lead under a ground strap...get close to +5v? Now place the meter on the AC setting...see any significant voltage? If you see more than...say .2vac, you have a capacitor problem...if not, change out the +5v rectifier, I have fixed 3 late model Sega driver boards with failed rectifiers in the past year...this problem seems to be quite common these days...

Dumb noob question:   I'm assuming I'm testing with the power on, where do I test, on the back side (output) of the capacitor? This seems obvious, but I want to make sure. Thanks for the help QBert.

[lilshawn]

worst case if you can find the 5 volt test point, put your black meter probe on the metal of the backbox ground... and the red lead on the case of the silver big round thingie inside of the heatsink on the top left side. that is your 5 volt regulator.

[LLUncoolJ]

OK, the board diagramshows 2 test points (24 guage wire loops), one being directly below the BRDG21 rectifier shown in the picture. I'm guessing that would b the logical place for the 5V. The other is on the right side of the board. One is labeled FET TPL1, the other is TIP TPL3. So find the one that is reading 5V and compare DC vs AC...easy enough.

[LLUncoolJ]

OK, I just tested the 5V DC, it read pretty close. Then 5VAC, it pegged the needle...so capacitor, no? Well, I shut the door and preesed start out of curiousity and played 2 games without incident. I opened it back up and took readings again, same thing. Then shut it and played another complete game. So what's going on here? 

[lilshawn]

OK, I just tested the 5V DC, it read pretty close.

 what's pretty close?  4.91 volts is known to make a game reset. digital is the way to go here an analog isn't going to be quite accurate enough. i would say borrow or buy one if you can. it will be 10 bucks well spent.

Then 5VAC, it pegged the needle...so capacitor, no?

i don't know if you know how to properly use a meter, so we will just throw this result out for now... again we are talking a few thousanths of a volt

Well, I shut the door and preesed start out of curiousity and played 2 games without incident. I opened it back up and took readings again, same thing. Then shut it and played another complete game. So what's going on here? 

dunno, but guaranteed if you mash on both of the flippers i'm sure that you'll see the 5 volt fluctuate. in anyways...

we are going to now systematically eliminate about 75% of all problems... be sure you can dedicate at least 3/4 of an hour for this procedure...

i'm gonna haft to ask you to go ahead and start at one end of the machine's boards and go ahead and unplug a connector, and then plug it back in again, one at a time as not to get lost or forget where it came from. ( i forget which header the 50 volt solenoid connector goes all the time since there are 2 connectors in the same spot.) make sure you get them all. you don't need to leave them unplugged for any amount of time just pull and push. take care not to rip out any wires or bend any pins. don't get all crazy, take your time, we have alloted plenty.

once you're done that i'm going to get you to go ahead and take a screwdriver and slightly loosen, then retighten all the screws holding the boards to the backbox...these points are ground. you want to make sure they are snug.

after that, your going to then close up the machine, turn it on and leave it for about 20 minutes. if it does not spontaneously reset in that time, play a few games. if it still decides to reset, come back here for further diagnostic help.

hopefully you get lucky and that will be it.

[LLUncoolJ]

Did all the loosening and tightening. Turned it on and it immediately reset...several times. The first time I noticed was after it was turned on, as soon as the backbox light licked on, it would reset. This thing seems to work according to the weather.

[lilshawn]

sounds likely the bridge might be getting wore out.

sometimes the bridge will work okay, but a small dip or surge in power will cause one of the diodes in the bridge to short or go open, causing the 5 volts to go wacky for a second...causing the reset watchdog to trip and reboot the machine.

i believe indeed that the bridge for the 5 volt is "BRDG21" possibly "C203" as well but do the bridge first.

the bridge item number is "DB3501" "35 amp silicon bridge rectifier. you will have to check and make sure that it has terminals not wires, as it often comes in both styles.

[LLUncoolJ]

Thanks lilshawn, that's kinda what I am leaning toward. I want to pull the board and take a look and see if replacing these is in my skillset. I'm not a very experienced solderer.

[lilshawn]

the easy way is to use a pair of cutters and nip off the bridge. that way you will have an easier time removing the stumps one at a time than trying to get them all at the same time. heat the nub up not the circuit board or you will wreck the trace (the copper conductor attached to the board).

clean out the holes using soldering braid (available where you buy soldering irons and solder) or a "solder sucker" in a pinch i've used a straw to clean out the holes. BLOWING not sucking!!

align the new bridge (it has tabs turned every which way...the bridge will only go in one way.)

heat up the leg and touch the solder to it, once you have enough the solder will flow down sticking to the leg in the process... then stick to the actual circuit board trace. doing it this way will ensure that the solder has stuck to the leg which is thicker metal and harder to heat up. otherwise what happens is what's known as a cold solder joint, and the solder is stuck to the trace but actually forms a pool of flux around the leg, making no (or very poor) connection.

[shardian]

Regarding the pin repair parent.

If he maintained route pins... DON'T LET HIM TOUCH YOUR GAMES!!!!!!

If he is a hobbyist who cares deeply for his games, then let him help.

All it takes is bringing an 'operator maintained' pin back to health to know that not everyone who's ever worked on a pin actually knows what they are doing.