New guy question

When I power it up I here a slight humming or buzz sound when I put my ear by the chassis. So it's getting some juice.

i have seen people install flybacks and they aren't tight and fully seated to the pcb and/or the pins aren't fully extended through the pcb when soldered and that bad connection causes that noise.
 
So I was busy for a few days and had time to mess with the cabinet tonight. Pulled the chassis pcb and inspected the flyback and it looks good as far as pins and solder. Then I noticed the 2a fuse on the board had a burnt spot on the glass. It wasn't broke in an obvious way so I pulled and tested it and it was bad. I went to the auto parts store and they only had fast burn 2a fuses. I bought them anyway and put it in hooked it up and still a blank screen. Pulled it and the fuse was toast lol. I will try to find a place in town that has the slow burn fuse tomorrow afternoon and try again.
 
So I was busy for a few days and had time to mess with the cabinet tonight. Pulled the chassis pcb and inspected the flyback and it looks good as far as pins and solder. Then I noticed the 2a fuse on the board had a burnt spot on the glass. It wasn't broke in an obvious way so I pulled and tested it and it was bad. I went to the auto parts store and they only had fast burn 2a fuses. I bought them anyway and put it in hooked it up and still a blank screen. Pulled it and the fuse was toast lol. I will try to find a place in town that has the slow burn fuse tomorrow afternoon and try again.

i stock every fuse for all arcade and pinball games.
https://www.arcadepartsandrepair.com/product-category/fuses/

check your HOT and diodes in the power supply section(d19-d22) if you popping fuses before trying it again and wasting fuses. make sure to always use the correct type/rated fuses too.
 
Okay so I set the multi meter to diode setting and tested the d19 - d22. Reading was between 540 and 550 on all four. The hot I put the black lead on center and red lead on left and read 009 same when I put red lead on right. Not sure if I did that right and what it means.
 
So I found this old post. He says the hot should read between .400 and .700
Mine reads 009. Is that possibly the issue and should be replaced along with a new fuse?
 

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So I found this old post. He says the hot should read between .400 and .700
Mine reads 009. Is that possibly the issue and should be replaced along with a new fuse?

if your that far out of the range on diode test than .009 is bad.
 
Okay security001, just placed an order for a new hot and some fuses. Thanks helping me work through this.
 
So I put in a new HOT New flyback and tested the d19 20 21 and 22. When I hook it up it blows the fuse still. I will include pics maybe you will see something idk. I'm at the point where I'm ready to mail this pos off to someone who knows how to fix it. I'm very frustrated.
 

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So I put in a new HOT New flyback and tested the d19 20 21 and 22. When I hook it up it blows the fuse still. I will include pics maybe you will see something idk. I'm at the point where I'm ready to mail this pos off to someone who knows how to fix it. I'm very frustrated.

have you checked the critical safety cap and see if its shorted. c36/c69
 
I can't see the insulator in between HOT and heat sink. Without that fuse and HOT will blow.
 
So I want to make sure I'm testing these properly. I attached a picture of how my multi meter was set up for a continuity test.

C36 there was a beep and meter reads 001

C69 there is no beep and meter reads 470 or 490 if I switch black and read leads
 

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I just finished crawling on my hands and knees in the garage searching under my work table and found this..... looks like there was some sort of white paste on it before. So does this mean I just ruined the brand new hot I installed last night?
 

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Most likely. HOTs with built-in damper diode test like this out of circuit when they're good:

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Those values are just an indication, they don't have to be exactly those (but the second is slightly higher than the first). And if your DMM shows results in millivolts, 0.460 will be 460.

Reversing the probes will give no reading (display remains 1). Since there is a resistor across Base and Emitter, that junction is tested by using the lowest resistance setting (200 ohm) on the multimeter and you'll read about 40-50ohm.
 

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I just finished crawling on my hands and knees in the garage searching under my work table and found this..... looks like there was some sort of white paste on it before. So does this mean I just ruined the brand new hot I installed last night?

you will have to test the HOT but with no mica its probably bad. you need a good mica and new thermal paste so make sure to clean all the old paste before putting new paste on and use the paste very liberally.
 
Besides testing the HOT off circuit, you should also test continuity across the point where the middle leg of the HOT was and a ground point (like the main heat sink). If you have continuity there is something shorted on the chassis.
 
Okay so when I test the hot it reads 001
When I test center pin of hot to heat sink it also reads 001
 
When I test center pin of hot to heat sink it also reads 001

Just to be sure: the HOT is no longer there and you're putting the probe on the pad where the center pin previously was, correct?

If so, remove C36 and check again the center pad of the HOT.
 
Okay I misunderstood. I did the test with the hot still soldered to the board. I'll remove it and test again
 
When I disconnected the hot from the sink and tested it he read 460! Do you think if I get some thermal paste and use the insulator it might work? Need to see if I can find some of that paste.
 
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