Replacement part for MCR board question

Torin

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I have been reading through various posts where the inductors/chokes have smoked due to a short on the SSIO board. Well, this happened to me. I tracked down the short and now am replacing the inductor/choke at L116 on my Tron board. Please see the picture for the part I am referring to.

I have found these three options on Mouser and was wondering which one would work for what I am replacing. Thanks for the help.

652-9250A-103-RC
MFG Part No:9250A-103-RC
9250A-103-RC
Bourns Fixed Inductors
US HTS:8504508000 ECCN:EAR99 COO:VN


652-77F100K-TR-RC
MFG Part No:77F100K-TR-RC
77F100K-TR-RC
Bourns Fixed Inductors
US HTS:8504504000 ECCN:EAR99 COO:TW


70-IR04EB100K
MFG Part No:IR04EB100K
IR04EB100K
Vishay Fixed Inductors
US HTS:8504508000 ECCN:EAR99 COO:MX
 

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652-77F100K-TR-RC
MFG Part No:77F100K-TR-RC
77F100K-TR-RC
Bourns Fixed Inductors
US HTS:8504504000 ECCN:EAR99 COO:TW
I used this part on my board with no problem at all (also available here at jameco). I couldn't find a complete spec but 10uH @ 500mA seemed like a pretty reasonable replacement.

That is a common problem. Any dead short on the +12v and that choke is the first part to die.
 
I used this part on my board with no problem at all (also available here at jameco). I couldn't find a complete spec but 10uH @ 500mA seemed like a pretty reasonable replacement.

That is a common problem. Any dead short on the +12v and that choke is the first part to die.

Cool. Thanks man! The smoke and stench from that thing frying was unbearable.
 
Last edited:
Hi;
I have the exact same failure, could you tell me what component on your SSIO dead-shorted?
Thanks
Jeff
 
I have been poking around the SSIO and found a short across CP204.... I cut one lead to be sure and there is continunity between the 2 pads as well as to the pads on the cap to the right of it (sorry, don't have the schems in front of me).
I also noticed the someone cut one lead on both C128 and C129, was this a factory "mod"?
When I disconnected the SSIO from the other boards, the short on the power connector went away so my problem does lie on the SSIO somewhere.
Jeff
 
I have been poking around the SSIO and found a short across CP204.... I cut one lead to be sure and there is continunity between the 2 pads as well as to the pads on the cap to the right of it (sorry, don't have the schems in front of me).
I also noticed the someone cut one lead on both C128 and C129, was this a factory "mod"?
When I disconnected the SSIO from the other boards, the short on the power connector went away so my problem does lie on the SSIO somewhere.
Jeff
 
I have been poking around the SSIO and found a short across CP204.... I cut one lead to be sure and there is continunity between the 2 pads as well as to the pads on the cap to the right of it (sorry, don't have the schems in front of me).
I also noticed the someone cut one lead on both C128 and C129, was this a factory "mod"?
When I disconnected the SSIO from the other boards, the short on the power connector went away so my problem does lie on the SSIO somewhere.
Jeff

Thread resurrection, but I have the same problem where L116 on my Tron CPU board has blown and the CP204 on the Super Sound I/O Board is showing as short on the multi-meter so guessing that is the problem

Can anyone else confirm if this is a common problem or @jetusenet whether this fixed your issue?

Thanks!
 
There are 3 or 4 10uF tantalum caps on the 12v rail on the ssio. Any one or all of these can short out and cause the choke to overheat and go open, its not necessarily c204. You have to pull one leg of the caps on the 12v rail until you find and eliminate the short.
The choke on the cpu can be replaced with a piece of wire with no ill effects.
 
Tracing the +12V line

There are 3 or 4 10uF tantalum caps on the 12v rail on the ssio. Any one or all of these can short out and cause the choke to overheat and go open, its not necessarily c204. You have to pull one leg of the caps on the 12v rail until you find and eliminate the short.
The choke on the cpu can be replaced with a piece of wire with no ill effects.

That's great advice - many thanks and much appreciated

So looking at the schematics the 12V is largely around the 3800 at D3 which gets 12V in through pins 11 and 12 from J2 on the edge connector (+12V is also at the diagnostic port pins 5 & 7 [one fat pin after the 1 & 3 GND pin]) if my understanding is correct?

This also gets 6V in from the two 3404s at C10 and E10

Out of interest some capacitors are labelled CP000 and others C000 - are the CP ones just used on smoothing capacitors or similar between +V and GND?

On my SSIO board CP20 appears to be shorted (it meters with continuity) and I have both sides of that capacitor giving connectivity to +12V, so that would appear to be a definite replacement candidate there

I'm guessing +12V going straight to GND is what blew the choke / inductor on the Super CPU at L116...

Thoughts and musings on the above much appreciated!

Judder
 
In my case the choke / inductor had burnt out as well on the Super CPU board (L116 is the connection to the 12V part of the circuits so that had died).

CP20 on the Super Sound I/O board was showing as straight to ground, but after I removed it it tested fine as a 10Mf Capacitor so I looked at other 10Mf Capacitors on the same circuit

CP204 and C172 were both shorting to ground, so I removed one side of C172 and tested the capacitor and it was a short-circuit so that was definitely dead and needed removing

I replaced it with a modern 10uF Capacitor (same capacitance, just a modern way of writing the micro-farad unit) and now all of the above 10Mf/10uF Capacitors reported capacitance, about 4.5Mf / 4.5uf, and no shorts to ground

I'm still interested in the designation in the Midway schematics about the difference between CP labelled capacitors and C labelled capacitors if anyone knows?

DeadCapacitorLifted.jpg
 
L116 Smoked Found short at C172

Thanks all:

Recently purchased a Midway Kickman cab untested that was a warehouse find. When powering it up to test for the first time the choke at L116 immediately smoked. after reading this post and poking around on the board I found C172 to be shorted. One important thing that others have stated is you have to remove one leg of the caps from the board in order to check them for shorted condition. I had multiple caps appearing to check shorted because of the short at C172. After removing the bad cap from board the other caps did not check shorted. Basically if one cap goes bad and creates a short across two traces on the board it will make other components on those common traces to appear shorted. I still have to order a replacement cap for C172 as I don't have any on hand but with C172 checking a dead short on my continuity meter and other shorts gone with C172 removed I feel sure I have found the problem.
 
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