ML Purity set not producing sound

[Jennatolles]

Hey guys recently I was given the opportunity to take home some ML purity’s (2007) with the hope they would work. Unfortunately neither of them work. Both speakers fail to produce any sound. However one panel will create a slight buzz but outside of that zero output. I have tried both my main receiver and my Sonos amp to no avail between different brands of wires to swapping the power cords that were supplied. I decided to disassemble the speaker that had a slight buzz but still had no output. I have attached photos of both the back plate circuit board and the amp. If anybody could point me in the right direction that would be greatly appreciated. Thank in advance

 

[StimpyWan]

In the third picture, on what I assume is the bias voltage board, there's a grouping of 6 electrolytic capacitors. At least 1 of those capacitors appears to be leaking on top. One or 2 others look swollen, bulging on top. If so, you need new bias boards. Hopefully, ML still stocks the boards? The bias board in my EM-ESL's cost around $86, when I last ordered one. Yours shouldn't be too different in cost.

Good luck...!

 

[R.I.P]

FIRST STEP:
Prior to placing order verify everything other than loudspeakers are functioning without fault. Includes power cable, interconnect and music equipment etc.

SECOND STEP:
Like other members have mentioned, use the vacuum cleaner and see if sonics are back somewhat. If there is improvement or major improvement then panels are coated with dust and need to be washed.

THIRD STEP { undertake if electrostatic panel transparent yet no sound }:
Each Purity has one switching amplifier inside. In addition to high voltage power supply the switching amplifier circuit may need to be replaced too.

I guess the amplifier circuit perhaps available from ML is a greater expense than just the high voltage power supply circuit.

If unable to determine where the fault lies and perhaps both are faulty. Then buy from ML first pair the less expensive item namely bias board also called high voltage power supply circuit.

Install and see if sonics function. If they do not, the next step is to order, receive and install a switching amplifier circuit in both speakers. Hopefully by now the sonics will be there.

If after disassembling Purity unable to distinguish or identify bias board and amplifier circuit. Not a problem, just place order with ML for a pair high voltage power supply circuit. After receiving a new bias board you can match with the old bias board to determine or identify correctly the bias board also known as high voltage power supply circuit.

 

[Jennatolles]

FIRST STEP:
Prior to placing order verify everything other than loudspeakers are functioning without fault. Includes power cable, interconnect and music equipment etc.

SECOND STEP:
Like other members have mentioned, use the vacuum cleaner and see if sonics are back somewhat. If there is improvement or major improvement then panels are coated with dust and need to be washed.

THIRD STEP { undertake if electrostatic panel transparent yet no sound }:
Each Purity has one switching amplifier inside. In addition to high voltage power supply the switching amplifier circuit may need to be replaced too.

I guess the amplifier circuit perhaps available from ML is a greater expense than just the high voltage power supply circuit.

If unable to determine where the fault lies and perhaps both are faulty. Then buy from ML first pair the less expensive item namely bias board also called high voltage power supply circuit.

Install and see if sonics function. If they do not, the next step is to order, receive and install a switching amplifier circuit in both speakers. Hopefully by now the sonics will be there.

If after disassembling Purity unable to distinguish or identify bias board and amplifier circuit. Not a problem, just place order with ML for a pair high voltage power supply circuit. After receiving a new bias board you can match with the old bias board to determine or identify correctly the bias board also known as high voltage power supply circuit.

FIRST STEP:
Prior to placing order verify everything other than loudspeakers are functioning without fault. Includes power cable, interconnect and music equipment etc.

SECOND STEP:
Like other members have mentioned, use the vacuum cleaner and see if sonics are back somewhat. If there is improvement or major improvement then panels are coated with dust and need to be washed.

THIRD STEP { undertake if electrostatic panel transparent yet no sound }:
Each Purity has one switching amplifier inside. In addition to high voltage power supply the switching amplifier circuit may need to be replaced too.

I guess the amplifier circuit perhaps available from ML is a greater expense than just the high voltage power supply circuit.

If unable to determine where the fault lies and perhaps both are faulty. Then buy from ML first pair the less expensive item namely bias board also called high voltage power supply circuit.

Install and see if sonics function. If they do not, the next step is to order, receive and install a switching amplifier circuit in both speakers. Hopefully by now the sonics will be there.

If after disassembling Purity unable to distinguish or identify bias board and amplifier circuit. Not a problem, just place order with ML for a pair high voltage power supply circuit. After receiving a new bias board you can match with the old bias board to determine or identify correctly the bias board also known as high voltage power supply circuit.

Thank you for the advice. I will apologize I was not clear earlier the woofer and the panels produce no sound. I feel in my uneducated opinion it’s something to do with the power supply. After tinkering with some power cords I was able to get both speakers to admit a small hum/ buzz. I’m about to open the second speaker up. Will update.

 

[Jennatolles]

In the third picture, on what I assume is the bias voltage board, there's a grouping of 6 electrolytic capacitors. At least 1 of those capacitors appears to be leaking on top. One or 2 others look swollen, bulging on top. If so, you need new bias boards. Hopefully, ML still stocks the boards? The bias board in my EM-ESL's cost around $86, when I last ordered one. Yours shouldn't be too different in cost.

Good luck...!

Thanks for the advice! I’m going to get in contact with Martin Logan come Monday and see what I can get my hands on!