discs of tron power chassis

frytex

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I need some help with a power chassis for my discs of tron. I have unpluged everything from it but when i plug it in i still blows both 5amp fuses. Have tried everything i know (which is not much) but still nothing. If you want to walk through something let me know
 
Well, if everything is unhooked, there are only four things in that circuit. Two diodes, a big-ass cap, and a resistor.

Pull the bottom cover off of the unit. You can see four diodes on one side, and you are interested in the two that connect to the 100,000 uF cap (the cap is labeled on the top side), but you can just check all four. Set your meter to measure resistance, and then measure across each diode one way, then the other. You will get two different readings, and the two readings should be consistent across all four diodes.

The resistor is across the 100,000 uF cap. Check resistance, should be 50 ohm? (Not positive, should be printed on the resistor).

If these are OK, then probably is the big cap. Bob Roberts sells them--might was well change both while you're at it. $35/pair.
 
Are those the side monted peices all metal. I asked bob roberts he said he did not sell them. What is the proper name for that type of diode. I just bought the big ass cap from him last week so I do not think it is that.
 
I think we're talking about the same thing. These guys right here:

attachment.php


They are rectifier diodes, and the manual lists them as MR1120, which crosses to an NTE5870 at Newark:
http://www.newark.com/nte-electronics/nte5870/diode/dp/29C4740?Ntt=mr1120

Or cheaper at Mouser:
http://www.mouser.com/ProductDetail/NTE/NTE5870/?qs=EBYTIVOgCMe3lY2ahsm8kA==
 

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wanted the chime in before i opend my own thread. i recently got a satan's hollow and sent the boards aout for repairs and yadada....anyways go tthe boards back and i was dealing with a rather loud hum but mor elike a bus horn sound. anyways befor ei could sink my teeth into that problem i lost the game. i got half a screen black and half the screen white. after doing some troubleshooting and trying the boards and such feeds with my tron i narrowed it down to the iso transformer. now picking up on this thread i got two differt reading and i wanted to see if these were correct.

on one side of the diodes i got a slowly building up resistnace number of 52ohm. once i made contact the number climbed until it peaked at 52ohm. the other side i was reading 162ohm steady. can anyone help? the side with 162 ohm were going to the 2 big caps.
 
Just look for any one of the four diodes that measures different than the rest. You will have two readings when you measure both ways across the diode, but those two readings should be consistent for all four diodes.

Also, did you check all the fuses?
 
the fuses check out. the side farthest away from the two big caps read 52ohms. the side closest read 162ohms.
 
the fuses check out. the side farthest away from the two big caps read 52ohms. the side closest read 162ohms.
Are you putting the red lead on one side of the diode and the black on the other, or are you checking each side to ground?
 
red on one side and black on other.
So if all four measure roughly 52 ohms one way and 162 the other, then I think you'll have to keep looking. I have a tron that buzzed really badly then quit working, but it quit because it blew the fuse on the linear supply board. It turned out to be the big caps on that one.
 
does your meter have a diode test setting? Use that instead of ohms.
Depending on the meter, it may give you a number like 400-700, or .400 to .700. This is the voltage required to forward bias the diode and allow current to flow through it. Current should only flow in one direction. To test each diode properly, you'll most likely have to disconnect the leads from the 2 big caps and seperate them from each other before you can get a good reading -otherwise you'll be reading across 2 diodes at once. You could also desolder the lead from the diode that runs to the cap and then test.
 
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