Help with Carver M1.5t

oldsthunder · 21st June 2006, 02:24 PM

I have been given an old Carver amp. The power transformer has been removed, apparently for testing and was included. Transformer seems to be fine, but two diodes were found to be shorted. I replaced the diodes and repaired the pcb foil pattern (burnt from excessive current)
Now to re-install the transformer I don't know where all the secondary leads attach. I assume the yellows go to the large bridge since they reach, but the orange leads and the red leads pose a problem. Can any one help me out with which go where. Thanks for any help you can offer.

tiltedhalo · 21st June 2006, 06:42 PM

RED, RED, ORANGE, ORANGE, top to bottom
red
red
orange
orange

check all your outputs, and HD diods, the original 3 amp power supply diods were a little on the small side but something else is probably wrong

PS the yellows do go to the bridge rectifier.

anatech · 22nd June 2006, 01:02 AM

Hi oldsthunder,
I'll bet the triac is shorted, or there are a few other problems that can come up. The triac is used as a voltage regulator. Do not short it!!

Normally a blown output will cause the amp to cycle and "try" to turn on. The protection circuit will keep turning it off. The voltage adjust control (pot on the board running back to front) can get noisy. This adjusts the DC rail voltages and they run close to the limits on the caps. Don't "twiddle" the control!!

If you still have the old dual section capacitors on that same board you may find them open. That can cause all kinds of trouble. Stick a meter on one of the two larger caps on the bottom of the chassis. The voltage should not go over 124 VDC under any circumstances. It tends to drift up and the caps are rated at 130 VDC. I set these at 118 VDC in view of this. Power loss is minimal.

Just so you understand, the power supply top rails sit at +/- 124 VDC for a factory setting, or down to 118 VDC. That is a ton of juice! This amp will deliver all the power it is rated for, so it is not a toy. It can kill you if you give it a chance. The caps do not discharge quickly either.

-Chris

21st June 2006, 02:24 PM	#1
oldsthunder diyAudio Member Join Date: Jun 2006	Help with Carver M1.5t I have been given an old Carver amp. The power transformer has been removed, apparently for testing and was included. Transformer seems to be fine, but two diodes were found to be shorted. I replaced the diodes and repaired the pcb foil pattern (burnt from excessive current) Now to re-install the transformer I don't know where all the secondary leads attach. I assume the yellows go to the large bridge since they reach, but the orange leads and the red leads pose a problem. Can any one help me out with which go where. Thanks for any help you can offer.

21st June 2006, 06:42 PM	#2
tiltedhalo diyAudio Member Join Date: Sep 2005 Location: Melbourne Florida	1.5t help RED, RED, ORANGE, ORANGE, top to bottom red red orange orange check all your outputs, and HD diods, the original 3 amp power supply diods were a little on the small side but something else is probably wrong PS the yellows do go to the bridge rectifier.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
my carver hr-752	adventfan	Solid State	13	18th March 2011 06:06 PM
Carver: PM1.5 vs PM 1.5A	AltheaToldMe	Solid State	1	20th January 2008 11:34 PM
Carver TFM-15 - Need Help!	crazygreek	Solid State	7	18th August 2007 04:41 AM
Carver 400	birdsvsdog	Solid State	2	20th November 2006 02:53 AM
:: Carver DTL ::	dhengkoel	Digital Source	1	2nd December 2003 01:44 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

22nd June 2006, 01:02 AM	#3
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	Hi oldsthunder, I'll bet the triac is shorted, or there are a few other problems that can come up. The triac is used as a voltage regulator. Do not short it!! Normally a blown output will cause the amp to cycle and "try" to turn on. The protection circuit will keep turning it off. The voltage adjust control (pot on the board running back to front) can get noisy. This adjusts the DC rail voltages and they run close to the limits on the caps. Don't "twiddle" the control!! If you still have the old dual section capacitors on that same board you may find them open. That can cause all kinds of trouble. Stick a meter on one of the two larger caps on the bottom of the chassis. The voltage should not go over 124 VDC under any circumstances. It tends to drift up and the caps are rated at 130 VDC. I set these at 118 VDC in view of this. Power loss is minimal. Just so you understand, the power supply top rails sit at +/- 124 VDC for a factory setting, or down to 118 VDC. That is a ton of juice! This amp will deliver all the power it is rated for, so it is not a toy. It can kill you if you give it a chance. The caps do not discharge quickly either. -Chris

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)