2x the gate resistance is because the meter is reading through two gate resistors, one on the good transistor and one on the shorted transistor.
You desolder the resistor to isolate the gate completely.
You need to determine the reason why the side reading lower resistance is reading low. It may be another damaged FET or a bad driver.
You desolder the resistor to isolate the gate completely.
You need to determine the reason why the side reading lower resistance is reading low. It may be another damaged FET or a bad driver.
the FETs were all new i replaced them all and none readed continuity between any legs
anyways why would they read -9V and +9v on the right side.. and 0.8V on the left side...
and why would the Q106 gate resistor read 23.1ohm earlier and now read 25.1 like all the others.. could a remaining voltage in the caps alter the DMM reading on that only resistor ?
anyways why would they read -9V and +9v on the right side.. and 0.8V on the left side...
and why would the Q106 gate resistor read 23.1ohm earlier and now read 25.1 like all the others.. could a remaining voltage in the caps alter the DMM reading on that only resistor ?
I am a RF everything collector. I have 100's of RF amps 70's to present. I have been repairing for several years now. I buy broken and re-sell fixed and keep the ones I like. I have tons of rare RF gear and stock tons of parts.
Just love Rockford always have. Thanks to Perry I have been able to learn alot in repairs and how to use my scope. The ones that kick my butt I usually post for help. Perry is a very smart man, if anyone can get this amp going it will be him and you.
Just love Rockford always have. Thanks to Perry I have been able to learn alot in repairs and how to use my scope. The ones that kick my butt I usually post for help. Perry is a very smart man, if anyone can get this amp going it will be him and you.
Thanks for the offer. I have a junker BD1000 that's close enough.
The ones on the left have either a drive problem or another defective FET. If all read precisely the same resistance (within a few ohms), pull the driver IC and see if you read any low resistance between any legs on the driver IC. Legs 2 and 3 are connected together but the rest should read in the megaohms range.
The ones on the left have either a drive problem or another defective FET. If all read precisely the same resistance (within a few ohms), pull the driver IC and see if you read any low resistance between any legs on the driver IC. Legs 2 and 3 are connected together but the rest should read in the megaohms range.
yeah Perry is the man his knowledge is phenomenal.. i can understand some part of electronics and i am even assembling boards for o2 simulators and injector drivers for car tuning but this is nothing like repairing a car amp with those IC its much more complicated to understand what they do and how they work and what they are supposed to look like when working fine and i was working my way around his site and its absolutely ridiculous how much this dude knows!!! personally i dont even know how this guy can help us day after day without getting tired of us newbies... we know jack **** compared to him and he keeps helping!! I wish i could help him some other way around but i dont know what could help him lol
I am a RF lover too .. its the first amp brand i bought and i always been loving them that is why i want to repair this amp so bad it is actually the first one i bought and if the transfo strand did not touched the back cover at first it would still be working strong its sad that a little flaw in design make this bad boy fail...
they always attracted me and they deliver as expected... what other company could have made a 30 000watt amp... they are just ridiculous i love them!!
I am a RF lover too .. its the first amp brand i bought and i always been loving them that is why i want to repair this amp so bad it is actually the first one i bought and if the transfo strand did not touched the back cover at first it would still be working strong its sad that a little flaw in design make this bad boy fail...
they always attracted me and they deliver as expected... what other company could have made a 30 000watt amp... they are just ridiculous i love them!!
Perry is right the BD10001 I just repaired, I was getting very wierd readings on the output fets I replaced. The mosfet driver (MIC4420CT) was the culprit. As soon as I changed it my readings were the same as the other good known and working fets. Remove it from the circuit and test it as Perry has explained.
i was remeasuring everything on the left side to confirm before removing the board and desolder U6 and i noticed some weird readings
for the right side there is nothing low in resistance between the legs the only readings i get are the caps charging/discharging
but for the left side its much it really different and Q106 looks thrashed
Q106
1-3 384 ohm
1-2 0.5 ohm
2-3 384 ohm
this one is ******* busted... they were all new and it looks dead... i am shure i measured them all after soldering them to the MEHSA according to what you said in case they got shorted cause of the heat and nothing was shorted but maybe i passed on that one... anyways ill order 1 3415 and 1 6215 to replace this one and the one that poped open...
Q25-Q110-Q111-Q112(for Q112 i am measuring the cut legs of the transistor on the board the transistor is out of the circuit)
pin 1-3 402 ohm
pin 1-2 cap charging/discharging
pin 2-3 caps charging/discharging
Q104-Q105-Q8
pin 1-3 402
pin 1-2 50ohm
pin 2-3 384
i will remove U6 and measure it right now and tell you the results...
I know its hard to tell but do you think it could fix the popping and the poor quality playing cause of that ? cause i dont mind putting parts to repair the amp its just a pita to order and pay 15$ shipping everytime for a 2$ part... i dont mind getting all at the same time but pay 15$ of shipping to order one IC (U6) that costs 2$ is kind of irritating
specially when i am looking at digikey/newark/allied they dont have it in stock ...
so i dont know if we can continue to measure to figure out if something else is wrong according to what i told you that looked wrong with the amp!!
for the toroid strand ... if i put one end of the DMM on the strand and try to figure out where it leads to to know wich one failed... i read 0.5 ohm on both big strands of twisted wires that are on the upper side of the toroid nothing on all the other spots.
could this make the left sides output fets not work ? or is this related to the parrallel strands you were talking about that wouldnt make much of a difference..
sorry for all those questions i am just giving you as much as i can before dissassembling everything
for the right side there is nothing low in resistance between the legs the only readings i get are the caps charging/discharging
but for the left side its much it really different and Q106 looks thrashed
Q106
1-3 384 ohm
1-2 0.5 ohm
2-3 384 ohm
this one is ******* busted... they were all new and it looks dead... i am shure i measured them all after soldering them to the MEHSA according to what you said in case they got shorted cause of the heat and nothing was shorted but maybe i passed on that one... anyways ill order 1 3415 and 1 6215 to replace this one and the one that poped open...
Q25-Q110-Q111-Q112(for Q112 i am measuring the cut legs of the transistor on the board the transistor is out of the circuit)
pin 1-3 402 ohm
pin 1-2 cap charging/discharging
pin 2-3 caps charging/discharging
Q104-Q105-Q8
pin 1-3 402
pin 1-2 50ohm
pin 2-3 384
i will remove U6 and measure it right now and tell you the results...
I know its hard to tell but do you think it could fix the popping and the poor quality playing cause of that ? cause i dont mind putting parts to repair the amp its just a pita to order and pay 15$ shipping everytime for a 2$ part... i dont mind getting all at the same time but pay 15$ of shipping to order one IC (U6) that costs 2$ is kind of irritating
specially when i am looking at digikey/newark/allied they dont have it in stock ... so i dont know if we can continue to measure to figure out if something else is wrong according to what i told you that looked wrong with the amp!!
for the toroid strand ... if i put one end of the DMM on the strand and try to figure out where it leads to to know wich one failed... i read 0.5 ohm on both big strands of twisted wires that are on the upper side of the toroid nothing on all the other spots.
could this make the left sides output fets not work ? or is this related to the parrallel strands you were talking about that wouldnt make much of a difference..
sorry for all those questions i am just giving you as much as i can before dissassembling everything
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A leaking output or driver could cause the popping. What appeared to be happening was that one or more FETs were conducting causing the voltage to be driven to the speaker terminals. When the amp came out of mute/protection, the drive circuit corrected for the DC.
You can't replace only two of the outputs. You will have to replace all of the 8 that were on the side with the two that failed.
If the drive circuit or an output transistor was defective, that could cause the output to be weak or distorted.
Do you have a scope?
You can't replace only two of the outputs. You will have to replace all of the 8 that were on the side with the two that failed.
If the drive circuit or an output transistor was defective, that could cause the output to be weak or distorted.
Do you have a scope?
yes i have a scope at my job
i already replaced all of the FETs cause i could not replace them with the same part number so i repalce them all... i would have to replace them all again cause one was defective and one blew out ?? even if i can replace the failed one with the same part number??
finally i removed U6 from the top of the board with desoldering wick without removing the board from the casing cause i didnt want to dissassemble everything tonight and be all gunked up from cleaning the thermal compound ill do it when i will be at the point of replacing the failed components... are the heatsink tab supposed to be welded to the board? cause there seem to be a spot for it to be welded but it was not and i can see at least one other that is wobbling a bit cause the heatsink tab is not soldered to the board
so i have the results for U6 but you said earlier that pin 2 and 3 were connected together did you mean pin 2 and 4 ? cause when i look at the diagram it says pin 2 and 4 are grounds so i dont think it would be 2 and 3 just want to confirm
anyways the results are for U6 MIC4420CT
2-3 236 ohm
2-4 0.7 ohm
2-5 80 ohm
3-4 238 ohm
3-5 154 ohm
4-5 80 ohm
the rest doesnt show continuity
I also measured everything around U6 the resistors and the continuity to where the points are supposed to go and everything is fine
i already replaced all of the FETs cause i could not replace them with the same part number so i repalce them all... i would have to replace them all again cause one was defective and one blew out ?? even if i can replace the failed one with the same part number??
finally i removed U6 from the top of the board with desoldering wick without removing the board from the casing cause i didnt want to dissassemble everything tonight and be all gunked up from cleaning the thermal compound ill do it when i will be at the point of replacing the failed components... are the heatsink tab supposed to be welded to the board? cause there seem to be a spot for it to be welded but it was not and i can see at least one other that is wobbling a bit cause the heatsink tab is not soldered to the board
so i have the results for U6 but you said earlier that pin 2 and 3 were connected together did you mean pin 2 and 4 ? cause when i look at the diagram it says pin 2 and 4 are grounds so i dont think it would be 2 and 3
just want to confirmanyways the results are for U6 MIC4420CT
2-3 236 ohm
2-4 0.7 ohm
2-5 80 ohm
3-4 238 ohm
3-5 154 ohm
4-5 80 ohm
the rest doesnt show continuity
I also measured everything around U6 the resistors and the continuity to where the points are supposed to go and everything is fine
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*** repost with corrections*** forget the previous message
yes i have a scope at my job
i already replaced all of the FETs cause i could not replace them with the same part number so i repalce them all... i would have to replace them all again cause one was defective and one blew out ?? even if i can replace the failed one with the same part number??
finally i removed U6 from the top of the board with desoldering wick without removing the board from the casing cause i didnt want to dissassemble everything tonight and be all gunked up from cleaning the thermal compound ill do it when i will be at the point of replacing the failed components... are the heatsink tab supposed to be welded to the board? cause there seem to be a spot for it to be welded but it was not and i can see at least one other that is wobbling a bit cause the heatsink tab is not soldered to the board
so i have the results for U6 but you said earlier that pin 2 and 3 were connected together did you mean pin 2 and 4 ? cause when i look at the diagram it says pin 2 and 4 are grounds so i dont think it would be 2 and 3 just want to confirm
anyways the results are for U6 MIC4420CT
2-3 236 ohm
2-4 0.7 ohm
2-5 80 ohm
3-4 238 ohm
3-5 154 ohm
4-5 80 ohm
the rest doesnt show continuity
I also measured everything around U6 the resistors and the continuity to where the points are supposed to go and everything is fine
you are the pro that will tell me if U6's results looks ok but i think its ok there is no real low readings that would show a short so could there be something wrong with U15 that sends a signal to U6? we checked the input of U15 on pin 2 and 3 but did not check the output on pin 7 of U15 or pin 1 of U6 to see if we had something there... I dont know if this would make sense to verify
also when you told me U15 looked OK on the input side are you shure? cause U15 really looked like U9 wich make the system work...
here is what i wrote you.. (just to be shure)
with the neg probe on neg terminal
U9
0V without remote
-4.35V protect LED ON
5.20V protect LED OFF
U15
0V without remote
-4.40V protect LED ON and stays the same when the LED goes off (isnt this weird ? the same voltage before and after the protect led is on... no positive after the led goes off ??)
with the neg probe on pin 3 of their respective octo-couplers
U9
0V without remote
-0.7 protect LED ON
1.44 protect LED OFF
U15
-0.03 without remote
-0.67 protect LED ON and stays the same when the LED goes off (same thing ... not changing after the protect led goes off...)
yes i have a scope at my job
i already replaced all of the FETs cause i could not replace them with the same part number so i repalce them all... i would have to replace them all again cause one was defective and one blew out ?? even if i can replace the failed one with the same part number??
finally i removed U6 from the top of the board with desoldering wick without removing the board from the casing cause i didnt want to dissassemble everything tonight and be all gunked up from cleaning the thermal compound ill do it when i will be at the point of replacing the failed components... are the heatsink tab supposed to be welded to the board? cause there seem to be a spot for it to be welded but it was not and i can see at least one other that is wobbling a bit cause the heatsink tab is not soldered to the board
so i have the results for U6 but you said earlier that pin 2 and 3 were connected together did you mean pin 2 and 4 ? cause when i look at the diagram it says pin 2 and 4 are grounds so i dont think it would be 2 and 3
just want to confirmanyways the results are for U6 MIC4420CT
2-3 236 ohm
2-4 0.7 ohm
2-5 80 ohm
3-4 238 ohm
3-5 154 ohm
4-5 80 ohm
the rest doesnt show continuity
I also measured everything around U6 the resistors and the continuity to where the points are supposed to go and everything is fine
you are the pro that will tell me if U6's results looks ok but i think its ok there is no real low readings that would show a short so could there be something wrong with U15 that sends a signal to U6? we checked the input of U15 on pin 2 and 3 but did not check the output on pin 7 of U15 or pin 1 of U6 to see if we had something there... I dont know if this would make sense to verify
also when you told me U15 looked OK on the input side are you shure? cause U15 really looked like U9 wich make the system work...
here is what i wrote you.. (just to be shure)
with the neg probe on neg terminal
U9
0V without remote
-4.35V protect LED ON
5.20V protect LED OFF
U15
0V without remote
-4.40V protect LED ON and stays the same when the LED goes off (isnt this weird ? the same voltage before and after the protect led is on... no positive after the led goes off ??)
with the neg probe on pin 3 of their respective octo-couplers
U9
0V without remote
-0.7 protect LED ON
1.44 protect LED OFF
U15
-0.03 without remote
-0.67 protect LED ON and stays the same when the LED goes off (same thing ... not changing after the protect led goes off...)
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Yes, 2 and 4.
The driver is definitely defective. The readings on the IC (out of the board) should be in the megaohm range.
The parallel outputs MUST match. Even if you could be guaranteed to get 2 replacements from the same batch as the ones you replaced, it's possible that the remaining ones are weakened and could fail prematurely when stressed. This could result in the failure of the other half of the outputs as well as both power supplies. The risk simply isn't worth it.
With a good cordless screwdriver, you could have the board out of the sink in about 1 minute. Don't buy a cheap, slow cordless screwdriver. I use the Milwaukee 0490-22 and it's very well suited for the job.
Removing the driver is just as quick. Heat the post for the driver's heatsink (if it has one - they generally do) and pull the heatsink off of the driver. Apply enough new solder to the legs so that laying down the tip of the iron between the legs heats all 5 legs at once. When the solder is hot on all legs, pull the driver out. It takes 1 minute or less.
To prevent the heatsink compound from getting all over everything, wrap the MEHSA strips with wide tape (packing, masking...). To remove it quickly from the strips, scrape the majority off with a piece of cardboard, plastic or stiff rubber and wipe the remaining compound off with a paper towel.
The driver is definitely defective. The readings on the IC (out of the board) should be in the megaohm range.
The parallel outputs MUST match. Even if you could be guaranteed to get 2 replacements from the same batch as the ones you replaced, it's possible that the remaining ones are weakened and could fail prematurely when stressed. This could result in the failure of the other half of the outputs as well as both power supplies. The risk simply isn't worth it.
With a good cordless screwdriver, you could have the board out of the sink in about 1 minute. Don't buy a cheap, slow cordless screwdriver. I use the Milwaukee 0490-22 and it's very well suited for the job.
Removing the driver is just as quick. Heat the post for the driver's heatsink (if it has one - they generally do) and pull the heatsink off of the driver. Apply enough new solder to the legs so that laying down the tip of the iron between the legs heats all 5 legs at once. When the solder is hot on all legs, pull the driver out. It takes 1 minute or less.
To prevent the heatsink compound from getting all over everything, wrap the MEHSA strips with wide tape (packing, masking...). To remove it quickly from the strips, scrape the majority off with a piece of cardboard, plastic or stiff rubber and wipe the remaining compound off with a paper towel.
the driver is the 5 pins U6 right ?
and the 8 pins U15 is an octo coupler ??
i dont have a cordless here .. i dont even have an allen bit that would fit the socket head allens.. the only thing i have is a standard allen key so its really long lol
its not that bad since its the only one i am repairing
do i only need to change the 4 FETs with the one that blew (in case the others would have been weakened) since the other was simply defective or i killed it when heating the FET on the heatsink board and it did not actually "BLOW"??
its a good idea to put more solder to heat all of the legs at the same time but usually i remove all of the solder with wick since i will have to do it anyways to reinstall the new part but ill keep that in mind
and for the compound i scrape it from both parts with a razor blade at a 90degree angle and it gets most of it on the first wipe ... honestly its probably cause i didnt want to remove the board with the allen key ... if i had a cordless with the right bit i would have probably done it it would have been shorter than ******* around to remove it from the top.. but it was not that bad... maybe 5 minutes
so i need to replace MIC4420ct and 4 3215 and 4 6215 ... ill replace them all since its only 10$ anyways .. would you happen to have a MIC4420CT that you could sell me ? when i look digi/newark/allied i cant find them nowhere...
and the 8 pins U15 is an octo coupler ??
i dont have a cordless here .. i dont even have an allen bit that would fit the socket head allens.. the only thing i have is a standard allen key
so its really long lolits not that bad since its the only one i am repairing
do i only need to change the 4 FETs with the one that blew (in case the others would have been weakened) since the other was simply defective or i killed it when heating the FET on the heatsink board and it did not actually "BLOW"??
its a good idea to put more solder to heat all of the legs at the same time but usually i remove all of the solder with wick since i will have to do it anyways to reinstall the new part but ill keep that in mind
and for the compound i scrape it from both parts with a razor blade at a 90degree angle and it gets most of it on the first wipe ... honestly its probably cause i didnt want to remove the board with the allen key ... if i had a cordless with the right bit i would have probably done it it would have been shorter than ******* around to remove it from the top.. but it was not that bad... maybe 5 minutes
so i need to replace MIC4420ct and 4 3215 and 4 6215 ... ill replace them all since its only 10$ anyways .. would you happen to have a MIC4420CT that you could sell me ? when i look digi/newark/allied i cant find them nowhere...
Quest Components Part Details
These guys have several and $2.50 is a good price I will be ordering some myself.
These guys have several and $2.50 is a good price I will be ordering some myself.
nice
they have them in stock and at a really good price
its sad they dont have irf6215 and 3415 to make one order at the same place...
anyways at least i can have some!!
do i need to change a bunch of mic4420 or can i only change one since they are not paired in parrallel ?
anything else you suspect to be defective perry?
they have them in stock and at a really good price
its sad they dont have irf6215 and 3415 to make one order at the same place...
anyways at least i can have some!!
do i need to change a bunch of mic4420 or can i only change one since they are not paired in parrallel ?
anything else you suspect to be defective perry?
thats what i tought its not critical like the parrallel components!
when you say you will be ordering some could you order 2 more for me and i will pay them to you with extra shipping to me ? it will be 5$ for the parts and 5$ for shipping will probably cover a lot more than what it would cost to ship it to me ... i am asking cause the minimum order on quest is 25$ and i am far from that
I can pay you in advance by paypal or whatever you like
when you say you will be ordering some could you order 2 more for me and i will pay them to you with extra shipping to me ? it will be 5$ for the parts and 5$ for shipping will probably cover a lot more than what it would cost to ship it to me ... i am asking cause the minimum order on quest is 25$ and i am far from that
I can pay you in advance by paypal or whatever you like
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