Hi!
I own a EPoX EP-61BXA-M, that used to have bad caps. Actually, the former owner, had a little trouble with this board, on the VRM, near the CPU slot1... a badcap vented and as a "bonus" a MOSFET near the badcap burned out, rendering the CPU -- a P2 350MHz -- dead.
The badcap was a TAYEH 10v 1000uF, and the MOSFET was a D50N03A. I canibalized a 6.3v 1200uF to put on the place of the 10v 1000uf (didn't have any 10v 1000uF, only a 10v 2200uF, but I didn't tried this one until a later time, further on this post). As I said canibalized a 6.3v 1200uF to put on the place of the 10v 1000uf because this capacitor has the same dimensions as the TAYEH one. I think I can do this, but, any enlightening about the is switch will be welcome. The board works well with this cap, so I guess, I did right, but any warnings/thoughts about long term effects that I could I expect from this replacement, will be much welcome
About the MOSFET, I went to the local electronics shop and I was told that a replacement for the D50N03A is a Philips BUK455 100A, which according to it's datasheet is a N channel, 100V, 26A(max) MOSFET . I was fooled by the MOSFET name BUK455 100A, as I thought this was a 100A MOSFET, but actually it's only 26A(max)!
Well I've replaced the burned MOSFET, and the computer work ok, except, that when I run a P3 600 on it, the MOSFET heats a lot, and eventually when I run P95 the MOSFET actually smokes (this is before I shut down the PSU, to prevent this MOSFET to burn out!) I was lead to the conclusion that something was not right!
Further searching on the web to a datasheet of the D50N03A leads to nothing! Except a thread on this forum, where, according to kc8adu
Super Moderator, on this thread https://www.badcaps.net/forum/showth...96&mode=linear, on the 7th post said that the D50N03A (original MOSFET), is a 30v 50A N-channel MOSFET.
So, I guess I was misinformed about the D50N03A replacement and as a consequence I'm running a BUK455 100A (100v, 26A, N-ch MOSFET) bove it's capabilities, when "Primming95" (P95 drains the max current to the CPU, and I think that slot1 P3 600 CPU drains up to 30A, well above the BUK455 100A max. 28A limit, and below the D50N03A 50A limit). I think I should replace the BUK455 100A (26A Idrain) to another N ch MOSFET with a 50A Idrain (according to kc8adu Super Moderator. I think this is MOSFET fault, as the overheating only happens when the CPU load is high, this is when the current drained is high!
What do you think?
Any help from him or any other members will be much appreciated! As a side note I used to think that the overheating of the BUK455 100A MOSFET was capacitor fault, so I switched the 6.3V 1200uF to a 10V 2200V, but this helped nothing. So, after I read the above thread, I think the MOSFET ovearheating problem is due to the 26A limitation of the BUK 455 100A which does not comply with the original (D50N03A) MOSFET specs which were (according to kc8adu Super Moderator), 30V, 50A.
Sorry for the long post, I think I've explained all that I've done, but if any doubt arises, please feel free to ask me!
TYA for any replies.
I own a EPoX EP-61BXA-M, that used to have bad caps. Actually, the former owner, had a little trouble with this board, on the VRM, near the CPU slot1... a badcap vented and as a "bonus" a MOSFET near the badcap burned out, rendering the CPU -- a P2 350MHz -- dead.
The badcap was a TAYEH 10v 1000uF, and the MOSFET was a D50N03A. I canibalized a 6.3v 1200uF to put on the place of the 10v 1000uf (didn't have any 10v 1000uF, only a 10v 2200uF, but I didn't tried this one until a later time, further on this post). As I said canibalized a 6.3v 1200uF to put on the place of the 10v 1000uf because this capacitor has the same dimensions as the TAYEH one. I think I can do this, but, any enlightening about the is switch will be welcome. The board works well with this cap, so I guess, I did right, but any warnings/thoughts about long term effects that I could I expect from this replacement, will be much welcome
About the MOSFET, I went to the local electronics shop and I was told that a replacement for the D50N03A is a Philips BUK455 100A, which according to it's datasheet is a N channel, 100V, 26A(max) MOSFET . I was fooled by the MOSFET name BUK455 100A, as I thought this was a 100A MOSFET, but actually it's only 26A(max)!
Well I've replaced the burned MOSFET, and the computer work ok, except, that when I run a P3 600 on it, the MOSFET heats a lot, and eventually when I run P95 the MOSFET actually smokes (this is before I shut down the PSU, to prevent this MOSFET to burn out!) I was lead to the conclusion that something was not right!
Further searching on the web to a datasheet of the D50N03A leads to nothing! Except a thread on this forum, where, according to kc8adu Super Moderator, on this thread https://www.badcaps.net/forum/showth...96&mode=linear, on the 7th post said that the D50N03A (original MOSFET), is a 30v 50A N-channel MOSFET.
So, I guess I was misinformed about the D50N03A replacement and as a consequence I'm running a BUK455 100A (100v, 26A, N-ch MOSFET) bove it's capabilities, when "Primming95" (P95 drains the max current to the CPU, and I think that slot1 P3 600 CPU drains up to 30A, well above the BUK455 100A max. 28A limit, and below the D50N03A 50A limit). I think I should replace the BUK455 100A (26A Idrain) to another N ch MOSFET with a 50A Idrain (according to kc8adu Super Moderator. I think this is MOSFET fault, as the overheating only happens when the CPU load is high, this is when the current drained is high!
What do you think?
Any help from him or any other members will be much appreciated! As a side note I used to think that the overheating of the BUK455 100A MOSFET was capacitor fault, so I switched the 6.3V 1200uF to a 10V 2200V, but this helped nothing. So, after I read the above thread, I think the MOSFET ovearheating problem is due to the 26A limitation of the BUK 455 100A which does not comply with the original (D50N03A) MOSFET specs which were (according to kc8adu Super Moderator), 30V, 50A.
Sorry for the long post, I think I've explained all that I've done, but if any doubt arises, please feel free to ask me!
TYA for any replies.
Any enlight about this, from you or another member will be much appreciated.
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