Re: EP 61BXA-M sucess story, but... [Fix complete!!!Pictures inside!!!]
Rainbow thanks for your feedback!
The specs of the CET CEB6030L (Logic Level) MOSFETyou gave me on your previous post:
" Rds(on)=20mohm @ Vgs=4.5V, Id = 52A continuous, 156A pulsed,"
were most helpful!
Also, the info that:
" Yes, you can use logic level mosfets for all motherboard VRMs"
was the definitve info I was looking for!
After I've read your reply I understood that if I wanted a MOSFET that won't overheat at Id("nominal-for-P3@600MHz-usage") = 20A (or more) I have to:
1 - get a Logic Level MOSFET;
2 - get one with at least Id(continuous) >=50A (or something like that), but NOT Id(max)=26A (like the BUK455-100A);
I've Googled a little bit for CET CEB6030L datasheet, found it, and study its characteristics.
Then I delved on my "dead-mobo-trash" and I found 2 x Fairchild FDB6030L (Logic Level MOSFET) on a dead Socket370 (Pentium 3 mobo). I thought that If these MOSFET's are on a P3 mobo then I assume that those specs were those I was looking for... presumably similar to those you gave me on your previous post.
Again, I've Googled a little bit for Fairchild FDB6030L datasheet, found it, and study its characteristics. The Fairchild FDB6030L specs are similar to those you advice me to. Its specs are:
48 A, 30 V ;
RDS(ON) = 13 mW @ VGS=10V ;
RDS(ON) = 17 mW @ VGS=4.5V ;
Critical DC electrical parameters specified at elevated temperature ;
High performance trench technology for extremely low RDS(ON) ;
175°C maximum junction temperature rating ;
so I've unsoldered these 2 x Fairchild FDB6030L, and tested them for eventual malfunctions (http://www.uoguelph.ca/~antoon/gadgets/mostest.htm. The 2 x Fairchild FDB6030L both passed the tests, so I though that I could give them a try!
Near the Fairchild FDB6030L datasheet ( http://www.fairchildsemi.com/pf/FD/FDB6030L.html ), on the Fairchild site, were some app notes for Katmai VRM...what a luck! Precisely what I'm looking for. I recalled what gonzo0815 had said something like: "look for schematics of the VRM on the driver chip datasheets". I browsed that PDF (, and voiláthe info I was looking for -- these Logic Level MOSFET were for 12V input --, precisely what I was looking for this mobo!
After some solder work, I've replaced the Philips-BUK455-100A (not-Logic-Level-MOSFET) for this Fairchild FDB6030L (Logic-Level-MOSFET).
Now, I've replaced only the BUK455-100A MOSFET. I've kept the (2nd) original MOSFET --the one that does not overheat. I know that you adviced me to replace the 2 MOSFET's on the mobo for 2 identical Logic-Level-MOSFETs, but since only one of them was "problematic, i.e., overheating" I assumed that I could keep the "not problematic, i.e., not-overheating" one. This one is still one of the originals, never replaced MOSFET.
After I replaced the MOSFET I've switched the power on and it worked! Then, I ran Prime 95 torture test and after the 1024K pass, the temperatures were about 43ºC on both MOSFETs @ room temperature = 17.1ºC If the room temperature raises to 37ºC (+20ºC that the current room temperature) I assume that both MOSFET will go up to 63~65ºC, under heavy load (Prime95), so I guess that this is normal, and I should not worry! Please, care to advise me IF I should worry about those temperatures under load!
Since both MOSFETs have the same temperature under load, running P95 on a P3@600MHz, THEN I assume that the original MOSFET -- the D50N03A --, is also a Logic Level MOSFET (Correct me IF this assumption is somehow wrong!), maybe with 50A, 30V, like kc8adu had mentioned on a earlier post, but since he had not documented it's words, I don't know for sure some other relvant characteristics, like Rds(on), etc. But I'll assume that they are slighty "worst" than those of the Fairchild FDB6030L , since P2(Klamamth/Deschutes) current requirements are slightly lower than Katmai (P3) current requirements.
The 2 x TAYEH 10v 1000uF Caps were also replaced for 2 x VIVA 10v 2200uF, found on a PSU. I don't know their ESR values, but since it's temperatures don't go above 45ºC under P95 @ room temperature = 17.1 ºC, I'll assume that maybe if it goes as high as 65ºC (@ room temperature = 17.1 ºC) I should not worry. Maybe some low ESR could help me a bit, but, hey, it's old material, if it's working with 0€ spent, why bother?
Well, this post is really long, but I hope it will help and encourage some other persons to carry on when they lost their hope. To finalize, here is the picture of the 2 x 10v 2200uF caps (tall, black caps, at the left), and the Fairchild FDB6030L Logis Level MOSFET (the MOSFET that is most on the left on the "2 x MOSFET cluster")
Again, Thank You All that feedback me!
Kind regards,
Mikeluz
Originally posted by Rainbow
The specs of the CET CEB6030L (Logic Level) MOSFETyou gave me on your previous post:
" Rds(on)=20mohm @ Vgs=4.5V, Id = 52A continuous, 156A pulsed,"
were most helpful!
Also, the info that:
" Yes, you can use logic level mosfets for all motherboard VRMs"
was the definitve info I was looking for!
After I've read your reply I understood that if I wanted a MOSFET that won't overheat at Id("nominal-for-P3@600MHz-usage") = 20A (or more) I have to:
1 - get a Logic Level MOSFET;
2 - get one with at least Id(continuous) >=50A (or something like that), but NOT Id(max)=26A (like the BUK455-100A
);I've Googled a little bit for CET CEB6030L datasheet, found it, and study its characteristics.
Then I delved on my "dead-mobo-trash" and I found 2 x Fairchild FDB6030L (Logic Level MOSFET) on a dead Socket370 (Pentium 3 mobo). I thought that If these MOSFET's are on a P3 mobo then I assume that those specs were those I was looking for
... presumably similar to those you gave me on your previous post.Again, I've Googled a little bit for Fairchild FDB6030L datasheet, found it, and study its characteristics. The Fairchild FDB6030L specs are similar to those you advice me to. Its specs are:
48 A, 30 V ;
RDS(ON) = 13 mW @ VGS=10V ;
RDS(ON) = 17 mW @ VGS=4.5V ;
Critical DC electrical parameters specified at elevated temperature ;
High performance trench technology for extremely low RDS(ON) ;
175°C maximum junction temperature rating ;
so I've unsoldered these 2 x Fairchild FDB6030L, and tested them for eventual malfunctions (http://www.uoguelph.ca/~antoon/gadgets/mostest.htm. The 2 x Fairchild FDB6030L both passed the tests, so I though that I could give them a try!
Near the Fairchild FDB6030L datasheet ( http://www.fairchildsemi.com/pf/FD/FDB6030L.html ), on the Fairchild site, were some app notes for Katmai VRM...what a luck! Precisely what I'm looking for.
I recalled what gonzo0815 had said something like: "look for schematics of the VRM on the driver chip datasheets". I browsed that PDF (, and voiláthe info I was looking for -- these Logic Level MOSFET were for 12V input --, precisely what I was looking for this mobo!After some solder work, I've replaced the Philips-BUK455-100A (not-Logic-Level-MOSFET) for this Fairchild FDB6030L (Logic-Level-MOSFET).
Now, I've replaced only the BUK455-100A MOSFET. I've kept the (2nd) original MOSFET --the one that does not overheat. I know that you adviced me to replace the 2 MOSFET's on the mobo for 2 identical Logic-Level-MOSFETs, but since only one of them was "problematic, i.e., overheating" I assumed that I could keep the "not problematic, i.e., not-overheating" one. This one is still one of the originals, never replaced MOSFET.
After I replaced the MOSFET I've switched the power on and it worked! Then, I ran Prime 95 torture test and after the 1024K pass, the temperatures were about 43ºC on both MOSFETs @ room temperature = 17.1ºC If the room temperature raises to 37ºC (+20ºC that the current room temperature) I assume that both MOSFET will go up to 63~65ºC, under heavy load (Prime95), so I guess that this is normal, and I should not worry! Please, care to advise me IF I should worry about those temperatures under load!
Since both MOSFETs have the same temperature under load, running P95 on a P3@600MHz, THEN I assume that the original MOSFET -- the D50N03A --, is also a Logic Level MOSFET (Correct me IF this assumption is somehow wrong!), maybe with 50A, 30V, like kc8adu had mentioned on a earlier post, but since he had not documented it's words, I don't know for sure some other relvant characteristics, like Rds(on), etc. But I'll assume that they are slighty "worst" than those of the Fairchild FDB6030L , since P2(Klamamth/Deschutes) current requirements are slightly lower than Katmai (P3) current requirements.
The 2 x TAYEH 10v 1000uF Caps were also replaced for 2 x VIVA 10v 2200uF, found on a PSU. I don't know their ESR values, but since it's temperatures don't go above 45ºC under P95 @ room temperature = 17.1 ºC, I'll assume that maybe if it goes as high as 65ºC (@ room temperature = 17.1 ºC) I should not worry. Maybe some low ESR could help me a bit, but, hey, it's old material, if it's working with 0€ spent, why bother?
Well, this post is really long, but I hope it will help and encourage some other persons to carry on when they lost their hope. To finalize, here is the picture of the 2 x 10v 2200uF caps (tall, black caps, at the left), and the Fairchild FDB6030L Logis Level MOSFET (the MOSFET that is most on the left on the "2 x MOSFET cluster")
Again, Thank You All that feedback me!
Kind regards,
Mikeluz
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