IGT S 8amp blows and only get fluorescent lights, no burn on pins

[thegarse]

Hello all, I just picked up an interesting Hot Peppers made in 89 that I’d like to fix for my dad. I’ve been into pinball for the last 5 years so minor maintenance is stuff I think I can do. This hot peppers is the only one that I’ve seen that does not have spin buttons only a change button (see pics). I bought this on sort of an a whim for a few hundred dollars so I don’t think I’m looking too bad even if I have to buy a few things.


Here’s the issue and my guess at the culprit. I only get the fluorescents to turn on, 8 amp was blown so I replaced it and it blew again, checked for burnt pins as I have seen suggested on this site, no issues with the connector. Battery is reading fine. I thought reseating everything was a good idea so I tried that. Blew another 8amp, looked at the board and didn’t really see anything odd. The metal on the game has some corrosion from drink spills but all the ICs are fine. There are some diodes that give me continuity but I did not desolder and test only tested them in place. D2 diode did this and 2 of the diodes above the big caps also gave funny readings. Could this be the culprit? How can I read the diode to see what kind I need? Anyway happy to see a community of helpers similar to pinball folk. Also I have no keys, can I install a momentary switch for the jackpot key? Thanks in advance.


Oh I remembered something as I was posting pictures. The interconnect board had what appeared to be a hot resistor and it cooked the insulating plastic but then you pull the plastic back the resistor looks fine. Should I be worried about that?

[thegarse]

Asking a question, is this post not visible until I’m a contributing member? If so I’ll pay the $10 for 30 days.

[Jim]

Usually there are two areas that would cause this fuse to blow.  to eliminate which one:  pull the board, turn on the power, see if the fuse blows, if it does ,more then likely the candle could be your problem, unplug it and see if the fuse still blows.   the second area would be on the board itself, usually D-2, a Zenier  diode,  this uses the 8vac to convert it to the +VB dc voltage.

Hope this helps

Jim

[RB]

Have you checked the power supply for loose metal objects (coins, tokens, screws, nuts) that may have fallen inside causing a something to ground out?

[knagl]

Asking a question, is this post not visible until I’m a contributing member? If so I’ll pay the $10 for 30 days.

This looks like it's a moot point since you're showing as a contributing member (thanks!), but no, you do not need to be a contributing member for your posts to show up here or to get assistance with your machine. We help folks daily regardless of whether or not they financially contribute to the site.

While this is unlikely to be the reason for the fuse blowing, in one of the pictures you posted it appears that the battery on your MPU board is showing signs of corrosion and leaking. You'll want to change that out before it damages the board.

[thegarse]

Thanks for your help so far. Decided to contribute as the resources already have been helpful. The fuse does not blow with the board removed. D2 was the one I was getting continuity on. I removed it and tested it loose and still got continuity, it’s labeled ICTE 12 / IN6376, I guess this is a bidirectional tvs diode so maybe the continuity is expected? I guess it couldn’t hurt to replace it and test. Where can I get one?

[Jim]

google that number,  digikey and mouser electronics come up, you can purchase it from these companies.

[thegarse]

Order from mouser is in. I'll report back this weekend. I did remove the main transformer and found a lot of coins back there. I also checked the battery, the brown spots appear to be a shoddy soldering job and they apparently kept touching the battery with the iron. More soon.

[Badbaud]

That diode is a Tranzorb, they function as a  over voltage surge protector.
When they detect an over voltage they conduct to compensate for the over voltage.
Eventually they fail and short out internally and need to be replaced.

[thegarse]

Hi all, I replaced the suppressor diode, I also did all the rectifier diodes and the big caps while I was in a soldering mood.


She’s alive! Got the 61 error, reset it and it works about 30% of the time. This is a pretty big improvement from being a paperweight. The errors I get are 41, 42, and 43. I get them randomly with not a lot of rhyme or reason to the error. Is this the reels showing their age or could the issue lie elsewhere? Thanks!

[Badbaud]

There are a couple of components that relate to all 3 reels.
A large capacitor that filters the reel motor voltage, any ripple on this capacitor can cause random 41, 42, 43 tilts.

The large TO220 transistor TIP125 that provides power to all 3 reels, it turns on full to kick start the reel spin then drops voltage slightly when all 3 reels are spinning.
A 3904 TO92 transistor that drives the base of the TIP125.
A 6N139 optoisolator that translates Vcc voltage to Vb voltage to read the reel optics, it is much deeper in the electronics design.
Worst case you could send the board to my shop so I can scope it and determine what component(s) need to be changed.

[thegarse]

Update I couldn’t figure out what went wrong on my cap swap and rectifier swap but I did notice the traces would lift easily. I figured I’d try a new board as they are cheap and move my roms over. Success! Thanks all for your help.