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Infinity Epsilon accelerometer pcb needed!

N

Nicolai

New Member
Good evening.

I have a pair of Infinity Epsilons in good condition.
The previous owner told me that one of the woofer had been changed by a Infinity repair shop some years ago.
The bass sounds good, but if I play loud it has seemed as the servo makes one of the woofers pulsate at a very low frequency. Because of that I have not been able to play loud.

I took out both woofers and in the speaker that plays like it should it was a 902-6944 woofer and a old type pcb marked "Infinity PCB P/N 560-7504 Rev: C".
In the other speaker, the one with the problem, it was a 028-7052 woofer and a pcb marked "Infinity PCB P/N 560...5796 Rev A".

My SCU is as far as I know not a Rev A version. I am pretty certain of that.

I have got a spare 902-6944 woofer, but not another 560-7504 Rev C PCB. I guess these are impossible to get new anymore?
Any ideas what to do? Is it possible to make a copy of the pcb card perhaps?
Some good advice is very welcome:)

The PCB I think is correct:

560-7504%20Rev%20C_zpslqjopa06.jpg


560-7504%20Rev%20C_back_zpslnq0zqt3.jpg
 
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It looks like IF30003A ver C PCB works with the ver A SCU, IF30003 ver B PCB works with the older or original non ver A SCU from looking at the schematics but I could be wrong
 
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If the woofer that is working has the ver C PCB then your SCU should be ver A?
are you sure that your two PCB boards are not the same ones with different part #? the older non ver A PCB looks different... look at the PCB schenatics, it looks like ver C PCB is for the ver A SCU and your other PCB is marked ver A. the schematic does not show a ver A PCB, could infinity have marked them ver A instead of ver C in newer runs but they are the same, the schematic only shows ver B PCB for the non ver A SCU.
 
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Thank you Oketeekid for your help. Very appreciated!
Here is two pictures of the "Rev A" PCB from the other speaker. They look visually quite different, but it would be great if you could have a look and see what you think.
Again: thank you for your help!

560-5796%20Rev%20A_zpsyyx01m9w.jpg


560-5796%20Rev%20A_back_zpslz3emhom.jpg
 
Did you ever try connecting the good speakers xlr connector and it's amp/speaker wires to the speaker that has the problem so to test that the problem isn't the SCU box ?, you have to make sure you use all the connectors from the good speakers side and connect them to the bad speaker, you can not use a left side xlr with the right side amp/speaker wires or you will blow something.
 
I'm not an electronic engineer but to me they look about the same on a different PCB but I could be wrong, hopefully someone here with electronic experience can help you.
 
Thank you again.
Yes I have tried to switch everything in front of the speaker, but the problem remains in the same speaker so it is not in the SCU. That was my first guess as well.
I first thought the problem occured because the woofers were not identical (but both listed as belonging to the Epsilons, must have been 2 versions of the speaker), but when I saw that the PCB was not identical either I suspect that to be the cause instead.
 
Did you check on the back of the bad speaker that the xlr pins are clean also if the wires from inside the speaker are all soldered or connected to the xlr pins
 
Your SCU box should have a sticker on the bottom like this telling you what version you have
Lol where it says rev A is a small sticker that could easily fall off over the years, then how would you know what version you had
001.JPG
 
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I found out from infinity that 902-6944 woofer has no accelerometer sensor attached to it,
028-7052 woofer has the accelerometer sensor attached to it, other than that the woofers are the same
I gave them the part #'s of both your pcb boards but they said no info was available on them
I would try 028-7052 woofer from the bad speaker in the speaker that works make sure you use the rev C pcb from the speaker that works with it, if the 028-7052 woofer works in the other speaker then I would say that the rev A is the wrong pcb
 
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Good evening.
Thank you for checking. The 902-6944 does have the accelerometer attached. Both the one in my speaker and the new spare one I just bought has a accelerometer attached.
This was also the Infinity repair shop here in Norway said was the correct woofer and they said the same where I ordered my spare in USA.

The servo-function works as it should on both speakers up to a loud volume where the 028-7052 starts to pulsate.
In some of the Infinity documentation it says that 902-6944 is the woofer, in other Infinity papers it says that it is 028-7052.
They look exactly the same except that the accerelometer on the 028-7052 is square, while on the 902-6944 it is round.

Very hard to figure this out. Hmm..the negative side of owning old classic speakers I guess:rolleyes:
 
Nicolai said:
Good evening.
Thank you for checking. The 902-6944 does have the accelerometer attached. Both the one in my speaker and the new spare one I just bought has a accelerometer attached.
This was also the Infinity repair shop here in Norway said was the correct woofer and they said the same where I ordered my spare in USA.

The servo-function works as it should on both speakers up to a loud volume where the 028-7052 starts to pulsate.
In some of the Infinity documentation it says that 902-6944 is the woofer, in other Infinity papers it says that it is 028-7052.
They look exactly the same except that the accerelometer on the 028-7052 is square, while on the 902-6944 it is round.

Very hard to figure this out. Hmm..the negative side of owning old classic speakers I guess:rolleyes:
Click to expand...
Those woofers are the same, don't know why your 902-6944 had the accelerometer attached.
 
Resurrecting this old thread....
Did anyone find Rev C boards?
I have 2 pair of 30003 speakers and 4 80008A SCUs. I used 1 pair for many years with no problems after sitting for a number of years in the house, I hooked them up again and am experiencing SCU problems. When I power on the SCU and wait the 10 seconds to get the servo light, I get a loud noise from subs and the servo light goes out.... I see in the service manual, the 30003 and 80008A are not compatible...
I'm thinking of rewiring the original PCB to convert to Rev C in hopes this solves my issue. Another choice is to design a Rev C board and have them printed, then build new boards.
 
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