LEM T4A / D400 Amp Modules

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   Hi guys,

I have a load of LEM active cabs all with the same amp units and also the same faults.
All of the units power up. When sent 0dB and with the gain control at full level, the sound is barely noticeable and very distorted.

The T4's in particular tend to pop, click and hiss by themselves without audio connected, but otherwise display the same symptoms as the D400 units.

I have read that the EEPROM chip holder can become dry jointed and cause dsp problems, so on one of the units (from a d400) I soldered the chip directly to the board.

Still no luck.

Any ideas on what the fault could be?

Regards,
Toby

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mrspeedy Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 23 July 2011 Location: Cambridge UK Status: Offline Points: 511	Post Options Post Reply Quote mrspeedy Report Post Thanks(0) Quote Reply Topic: LEM T4A / D400 Amp Modules Posted: 06 March 2012 at 10:35pm
	Hi guys, I have a load of LEM active cabs all with the same amp units and also the same faults. All of the units power up. When sent 0dB and with the gain control at full level, the sound is barely noticeable and very distorted. The T4's in particular tend to pop, click and hiss by themselves without audio connected, but otherwise display the same symptoms as the D400 units. I have read that the EEPROM chip holder can become dry jointed and cause dsp problems, so on one of the units (from a d400) I soldered the chip directly to the board. Still no luck. Any ideas on what the fault could be? Regards, Toby

Beatfreak Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 09 March 2005 Location: United Kingdom Status: Offline Points: 201	Post Options Post Reply Quote Beatfreak Report Post Thanks(0) Quote Reply Posted: 09 June 2012 at 9:34am
	I have the same problem with a T4a, did you get anywhere with finding a solution for it? I like the sound of the speakers but it's no good having only one to use. I've even tried looking for a spare amp unit as it's the same for both the d400 and the T4a but no luck. I did even mange to speak to a company called fw greenhill and they were the uk distributors of LEM stuff and they tell me that GEM the parent company went into administration some years ago. They tried a repair but with no luck and when I found the schematic drawings for the module they told me it was unlikely it would be econmically sensible to try and repair!! Shame, so I keep looking for single speakers avaiable on ebay totake the module from.
	sound designs for sound individuals

jimi13243 Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 03 June 2014 Location: West Midlands Status: Offline Points: 77	Post Options Post Reply Quote jimi13243 Report Post Thanks(0) Quote Reply Posted: 27 July 2014 at 6:45pm
	You might like these http://www.gumtree.com/p/for-sale/lem-t6aactive-speakers3-waymade-in-italy1200w-pair/1073705098
	Peace and dub

Dgr12345 Members Profile Send Private Message Find Members Posts Add to Buddy List New Member Joined: 23 November 2021 Location: Cuba Status: Offline Points: 3	Post Options Post Reply Quote Dgr12345 Report Post Thanks(0) Quote Reply Posted: 23 November 2021 at 9:09pm
	Greetings ,, I need the drawing of the lem t4a amplifier ,,,, to be able to repair mine

Dgr12345 Members Profile Send Private Message Find Members Posts Add to Buddy List New Member Joined: 23 November 2021 Location: Cuba Status: Offline Points: 3	Post Options Post Reply Quote Dgr12345 Report Post Thanks(0) Quote Reply Posted: 23 November 2021 at 9:10pm
	The schematic plan

Dgr12345 Members Profile Send Private Message Find Members Posts Add to Buddy List New Member Joined: 23 November 2021 Location: Cuba Status: Offline Points: 3	Post Options Post Reply Quote Dgr12345 Report Post Thanks(0) Quote Reply Posted: 23 November 2021 at 9:15pm
	would you be so kind to give me the schematic of the lem t4a