Hi all,
Just came across this forum.. U guys here seems real knowledgeable..
Need some serious help.. Me reside in Singapore (Asia)
Got a Sony XM-D1000P5 Monoblock..
Dunno why it just died and blown my 60A fuse at my fuse box.
Send to Sony and found that the MOSFET SSP45N20A needs replacement. They quoted me damn ex, and say no stock, need to wait, dunno how long..
Search around, can't find the part, and realise later that it's an obseleted part.
Is there any other more common part that is more readily available that can do the same task?? While i try to look for IRFB42N20D as recommended in one of the threads.
Many thanks...
Just came across this forum.. U guys here seems real knowledgeable..
Need some serious help.. Me reside in Singapore (Asia)
Got a Sony XM-D1000P5 Monoblock..
Dunno why it just died and blown my 60A fuse at my fuse box.
Send to Sony and found that the MOSFET SSP45N20A needs replacement. They quoted me damn ex, and say no stock, need to wait, dunno how long..
Search around, can't find the part, and realise later that it's an obseleted part.
Is there any other more common part that is more readily available that can do the same task?? While i try to look for IRFB42N20D as recommended in one of the threads.
Many thanks...
hey i have a few transistors laying around that may help you out, free of charge just give me your address and i'll send them to you: if they are compatible:
ssp60n06
rfp70n06
irfz44
irf9540n
buz12
p60n06
rfp50n06
im to lazy to do a datasheet search for you so if you find one thatll work let me know
matt
ps..im in thailand so it shouldnt take too long to get to you
ssp60n06
rfp70n06
irfz44
irf9540n
buz12
p60n06
rfp50n06
im to lazy to do a datasheet search for you so if you find one thatll work let me know
matt
ps..im in thailand so it shouldnt take too long to get to you
This device is not usual at all, it's obviously not he classic switching device from a 12V push-pull PSU.
SSP45N20A, V(dss): 200V; 35A; 0.065 Ohm; advanced power MOSFET in 3-pin TO-220 (typical input capacitance appears to be 3.3nF)
It appears that Fairchild replaced the original SSP45N20 by SSP45N20A and then by SSP45N20B. You may still find the B version for sale, altough it's also obsolete now. How this can happen? Because car-audio manufacturers usually buy lots of long-ago obsolete parts at very good prices and build their amplifiers around them. (The worst case happens when a long-ago discontinued exotic IC has to be replaced).
The closest device in the current Fairchild catalog appears to be FDP39N20, and FQP34N20 may be also suitable. Note that both devices feature lower input capacitances (and gate charges) so the value of the gate resistor may be increased proportionally (theoretically).
Also, you may try to find similar devices from other manufacturers.
SSP45N20A, V(dss): 200V; 35A; 0.065 Ohm; advanced power MOSFET in 3-pin TO-220 (typical input capacitance appears to be 3.3nF)
It appears that Fairchild replaced the original SSP45N20 by SSP45N20A and then by SSP45N20B. You may still find the B version for sale, altough it's also obsolete now. How this can happen? Because car-audio manufacturers usually buy lots of long-ago obsolete parts at very good prices and build their amplifiers around them. (The worst case happens when a long-ago discontinued exotic IC has to be replaced).
The closest device in the current Fairchild catalog appears to be FDP39N20, and FQP34N20 may be also suitable. Note that both devices feature lower input capacitances (and gate charges) so the value of the gate resistor may be increased proportionally (theoretically).
Also, you may try to find similar devices from other manufacturers.
Hi guys,
Thanks for your help and offer..
I managed to get IRFB42N20D.
Will let you know if i need your transistor cos mine doesn't work.
Here's what happen.. Replaced all 8 SSP45N20A by IRFB42N20D.
Initial problem of 60A fuse blow upon power on is resolved.
But... the amp goes into protection mode when i turn up the volume( Not very loud, just moderate)..
Now headache.. Dun know what's wrong..
Looks like i got to give up on the amp??
Is there possibility that the replacement transistor is not compatible resulting in this problem??
Thank again.. Really appreciate..
Thanks for your help and offer..
I managed to get IRFB42N20D.
Will let you know if i need your transistor cos mine doesn't work.
Here's what happen.. Replaced all 8 SSP45N20A by IRFB42N20D.
Initial problem of 60A fuse blow upon power on is resolved.
But... the amp goes into protection mode when i turn up the volume( Not very loud, just moderate)..
Now headache.. Dun know what's wrong..
Looks like i got to give up on the amp??
Is there possibility that the replacement transistor is not compatible resulting in this problem??
Thank again.. Really appreciate..
Are the output caps (four 220uf/160v electrolytic caps near the speaker terminals) getting hot?
I had an amp that was doing the same thing (going into protect at high volume). I suspected the output inductor. I never had a chance to check it because the customer decided to pick it up before I received the service manual. If you want to pull it and have someone check it. It's supposed to be 230uH.
As a side note...
I used the same replacements as you but didn't want to recommend them because I hadn't successfully repaired the amp. I think they were a good replacement because the amp didn't pull excessive current at idle.
I had an amp that was doing the same thing (going into protect at high volume). I suspected the output inductor. I never had a chance to check it because the customer decided to pick it up before I received the service manual. If you want to pull it and have someone check it. It's supposed to be 230uH.
As a side note...
I used the same replacements as you but didn't want to recommend them because I hadn't successfully repaired the amp. I think they were a good replacement because the amp didn't pull excessive current at idle.
B&D Enterprises www.bdent.com has the SSP45N20A, pretty steep too $13.55 a pop.
I have an older MTX Thnder 8302 here that uses them in the amplifier section. It has a couple shot ones in it and then 6 of them still good. Still debating whether or not to cough up that much to repair an amp I'll probably never even use.
I have an older MTX Thnder 8302 here that uses them in the amplifier section. It has a couple shot ones in it and then 6 of them still good. Still debating whether or not to cough up that much to repair an amp I'll probably never even use.
If you get a newer 8302, the ones with surface mount resistors, they use irfb45n20d. Also all the mtx amps like 6500d or 4250d were upgraded to that transistor. I seen that digikey sells them. I think it was 2 to three dollars. Also that is excellent replacement tranisitor. Make sure you mearsured the resistors near the transistors that you replaced, they're known to blow or change value when under stress i think there 47 ohm.
Hi chlim74,
I recently had an MTX 6500d that was showed the same symptoms as your Sony (and the Sony that I worked on). It had SSP45N20As in it. I tried the IRFB42N20Ds and they allowed the amp to play at low to moderate volume but at high volume the amp would distort badly and shut down. After finding no other faults, I decided to try different transistors. When I used IRF3415s in it, it played fine. Although the 3415s are not suitable for your amp (too much rail voltage), you may want to try a different transistor. There may be nothing else wrong with your amp.
If you get the amp working, post the details of the repair.
I recently had an MTX 6500d that was showed the same symptoms as your Sony (and the Sony that I worked on). It had SSP45N20As in it. I tried the IRFB42N20Ds and they allowed the amp to play at low to moderate volume but at high volume the amp would distort badly and shut down. After finding no other faults, I decided to try different transistors. When I used IRF3415s in it, it played fine. Although the 3415s are not suitable for your amp (too much rail voltage), you may want to try a different transistor. There may be nothing else wrong with your amp.
If you get the amp working, post the details of the repair.
By what you tell, I assume that the amplifier is class-D, isn't it?
Then, the problem at high volumes may be due to cross-conduction (new MOSFETs turn-off slower and switching periods overlap) or due to spikes caused by a too fast turn-on activating the overcurrent protection prematurely. Either way, checking gate and drain waveforms with oscilloscope may be the best way to find a solution (that may be as simple as changing gate resistors).
Then, the problem at high volumes may be due to cross-conduction (new MOSFETs turn-off slower and switching periods overlap) or due to spikes caused by a too fast turn-on activating the overcurrent protection prematurely. Either way, checking gate and drain waveforms with oscilloscope may be the best way to find a solution (that may be as simple as changing gate resistors).
I have a mb Quart raa 1000 with the same problem. (it was a broken gift lol) It has a bad fairchild SSP45N20B. i went to the fairchild website and found the same info EVA found, it appears the fairchild SSP45N20B is obsolete, and replaced by the fairchild FDP39N20, and FQP34N20 as eva stated in a previous post "the values are not the same"
hence i have 2 questions:
1) has anyone tried with any luck relaceing a ssp45n20b with a FDP39N20 or FQP34N20?
2)if not is the amp worth fixing? (i have not tinkered much with this type of stuff but it looks like fun even if its not worth fixing)
hence i have 2 questions:
1) has anyone tried with any luck relaceing a ssp45n20b with a FDP39N20 or FQP34N20?
2)if not is the amp worth fixing? (i have not tinkered much with this type of stuff but it looks like fun even if its not worth fixing)
Heres a guy on e-bay but WHEW !!!
http://cgi.ebay.com/SSP45N20A-45N20...oryZ4666QQrdZ1QQssPageNameZWD1VQQcmdZViewItem
If you replace them with the IRF Fets the gate capacitance will be altered and the driver might not be able to handle that. I see MTX amps that use them all the time. And I have seen them being replaced By the the IRF fets mentioned, but the gate resistors were also changed to get the amp to work correctly.
Hope this helps abit
good luck try this link next time you need parts:
http://www.findchips.com/
http://cgi.ebay.com/SSP45N20A-45N20...oryZ4666QQrdZ1QQssPageNameZWD1VQQcmdZViewItem
If you replace them with the IRF Fets the gate capacitance will be altered and the driver might not be able to handle that. I see MTX amps that use them all the time. And I have seen them being replaced By the the IRF fets mentioned, but the gate resistors were also changed to get the amp to work correctly.
Hope this helps abit
good luck try this link next time you need parts:
http://www.findchips.com/
512-SSS45N20B
http://www.mouser.com/index.cfm?handler=home
This is a fully insulated version of the 45n20B it will not replace the 45n20A (like those used in the early MTX class D amps) but for the 45n20B it works (or always has for me). It's a fully insulated part so you should probably remove the insulator that was previously used and use heatsink compound between the transistor and the sink. You need to replace all that are in parallel with the one that failed.
http://www.mouser.com/index.cfm?handler=home
This is a fully insulated version of the 45n20B it will not replace the 45n20A (like those used in the early MTX class D amps) but for the 45n20B it works (or always has for me). It's a fully insulated part so you should probably remove the insulator that was previously used and use heatsink compound between the transistor and the sink. You need to replace all that are in parallel with the one that failed.
MTX Thunder 8302 problem!!!
Hello guys, I'm having the same problem with some shot FETs on my MTX amp, they are SSP45N20A actually three of them (2 from left channel and 1 from the right channel).
Did anyone come out with a positive research on what replacements to use?
Thanks for any help as i need this amp to be repaird ASAP.
Hello guys, I'm having the same problem with some shot FETs on my MTX amp, they are SSP45N20A actually three of them (2 from left channel and 1 from the right channel).
Did anyone come out with a positive research on what replacements to use?
Thanks for any help as i need this amp to be repaird ASAP.
Sorry to resurrect an old thread, but thought it might be useful to add to it.
I had an MTX 8302 that I replaced the 4 SSP45N20A on one channel with 4 IRF3415. I also had to replace a driver upstream of them. Now I had forgotten I fixed this amp, and put it into service as a subwoofer amp in my Explorer. I went a little overboard and had some fun and put 2x10s, 1x15, 1x12 on it wired 4 ohms. Ran it that way in the hot Texas summer. Then pulled the 15 and 12 and ran the 2x10s at 2 ohms. It finally gave up the ghost after months and months of abuse, at least 2 years. I just pulled it apart and only two of the 3415s went belly up.
So it seems the IRF3415 works great as Perry described above.
I had an MTX 8302 that I replaced the 4 SSP45N20A on one channel with 4 IRF3415. I also had to replace a driver upstream of them. Now I had forgotten I fixed this amp, and put it into service as a subwoofer amp in my Explorer. I went a little overboard and had some fun and put 2x10s, 1x15, 1x12 on it wired 4 ohms. Ran it that way in the hot Texas summer. Then pulled the 15 and 12 and ran the 2x10s at 2 ohms. It finally gave up the ghost after months and months of abuse, at least 2 years. I just pulled it apart and only two of the 3415s went belly up.
So it seems the IRF3415 works great as Perry described above.
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