Carver M 1.0t Heating up

If you have Carver repair questions, or can help other users with repairs, this is the place for it
Post Reply
NJ_Antonio
Newbie
Posts: 8
Joined: Tue Nov 25, 2008 10:52 am
Location: New Jersey

Carver M 1.0t Heating up

Post by NJ_Antonio » Thu Jun 04, 2009 9:58 am

Hi Carverophiles! I have a strange problems with my nice M1.0t. Inputting a 1K waveform, the output starts very low, suddenly increases a lot then it goes back to being very low and so on. While this is going on, the transformer buzz and Q130 becomes Very hot! So far I replaced various transistors such as Q120, 110, 117,118 etc. with those suggested forthe MkII modification and all the small value electrolitic caps plus those for the +-30 branch of the power supply which still shows a little ripple.

Any advice for troubleshooting is appreciated!

Thanks!
Antonio
1. Infinity Gamma w/servo, Audio Research D-250 Mk II + 2 bridged Hafler XL600, Audio Research SP6B, Denon DCD-1560, Denon turntable
2. Electrovoice Interface D, Kenwood M2A, C2, CD (in Italy)
3. Allison One, Dynaco 400, APT Holman pre, Technics CD, Luxman turntable (in Italy)
4. ADS L-1290/II, Carver M 1.0t, C-1, Pioneer CD
5. Phase Linear Andromeda III , 200 II & 300 II, C4000 II, Sony X-307 ES CD
6. JBL L-36 Decade, Fisher X-500B tube receiver, Yamaha 720 CD
7. Etc. Etc. Etc.

User avatar
BillD
R.I.P. Friend
R.I.P. Friend
Posts: 7126
Joined: Wed Jun 06, 2007 8:29 pm
Location: The west's most mid-western town, Scottsdale, Arizona

Re: Carver M 1.0t Heating up

Post by BillD » Thu Jun 04, 2009 10:07 am

If your power supply is still showing ripple, I'm betting on a bridge rectifier somewhere. You might try some freeze-it and spray around some of the rectifiers and see what happens.
It should sound like it isn't there!
There is a difference between hearing and listening...
Making life enjoyable through expensive electronics.
_________________
Carver: C-4000 & C-1 preamps, PSC-60 preamp/tuner, TX-11a tuner, M-400 (2), C-500, M-500, M-500t, M-500t Mk.II, A-500x, AL-III loudspeakers (2 pr.)
Sunfire:Theater Grand III processor, Ultimate Receiver, Cinema Grand Signature 400 ~ seven, True Subwoofer Mk. II, D-10 Subwoofer

NJ_Antonio
Newbie
Posts: 8
Joined: Tue Nov 25, 2008 10:52 am
Location: New Jersey

Re: Carver M 1.0t Heating up

Post by NJ_Antonio » Thu Jun 04, 2009 3:46 pm

Do you mean those diodes on the daughterboard next to the transformer? But why is Q130 quickly becoming hot?

Thanks for the input!
Antonio
1. Infinity Gamma w/servo, Audio Research D-250 Mk II + 2 bridged Hafler XL600, Audio Research SP6B, Denon DCD-1560, Denon turntable
2. Electrovoice Interface D, Kenwood M2A, C2, CD (in Italy)
3. Allison One, Dynaco 400, APT Holman pre, Technics CD, Luxman turntable (in Italy)
4. ADS L-1290/II, Carver M 1.0t, C-1, Pioneer CD
5. Phase Linear Andromeda III , 200 II & 300 II, C4000 II, Sony X-307 ES CD
6. JBL L-36 Decade, Fisher X-500B tube receiver, Yamaha 720 CD
7. Etc. Etc. Etc.

User avatar
BillD
R.I.P. Friend
R.I.P. Friend
Posts: 7126
Joined: Wed Jun 06, 2007 8:29 pm
Location: The west's most mid-western town, Scottsdale, Arizona

Re: Carver M 1.0t Heating up

Post by BillD » Thu Jun 04, 2009 4:09 pm

The ones I was thinking about were the packaged four prong bridge rectifiers.
It should sound like it isn't there!
There is a difference between hearing and listening...
Making life enjoyable through expensive electronics.
_________________
Carver: C-4000 & C-1 preamps, PSC-60 preamp/tuner, TX-11a tuner, M-400 (2), C-500, M-500, M-500t, M-500t Mk.II, A-500x, AL-III loudspeakers (2 pr.)
Sunfire:Theater Grand III processor, Ultimate Receiver, Cinema Grand Signature 400 ~ seven, True Subwoofer Mk. II, D-10 Subwoofer

NJ_Antonio
Newbie
Posts: 8
Joined: Tue Nov 25, 2008 10:52 am
Location: New Jersey

Re: Carver M 1.0t Heating up

Post by NJ_Antonio » Fri Jun 05, 2009 5:46 pm

Ok. Q 130 substituted with NTE equivalent. Now does not get heated quickly anymore. Also the 8 raised diodes have been substituted with NTE 576 equivalents. None of the old ones tested bad. Also all diodes in the power supply have been tested good.

Now the amp stays on for 1/2 second ( I can see a nice waveform at both outputs) with the meters increasing. Then it stops and there is no output for like 2-3 seconds; then does this again. When it goes on, 60 and 100 V rails drop slightly. 30V rail still shows some ripple on both the + and - site.

What would you suggest as next move, beside flattening the amp into a pancake?

Thanks

Antonio
1. Infinity Gamma w/servo, Audio Research D-250 Mk II + 2 bridged Hafler XL600, Audio Research SP6B, Denon DCD-1560, Denon turntable
2. Electrovoice Interface D, Kenwood M2A, C2, CD (in Italy)
3. Allison One, Dynaco 400, APT Holman pre, Technics CD, Luxman turntable (in Italy)
4. ADS L-1290/II, Carver M 1.0t, C-1, Pioneer CD
5. Phase Linear Andromeda III , 200 II & 300 II, C4000 II, Sony X-307 ES CD
6. JBL L-36 Decade, Fisher X-500B tube receiver, Yamaha 720 CD
7. Etc. Etc. Etc.

User avatar
BillD
R.I.P. Friend
R.I.P. Friend
Posts: 7126
Joined: Wed Jun 06, 2007 8:29 pm
Location: The west's most mid-western town, Scottsdale, Arizona

Re: Carver M 1.0t Heating up

Post by BillD » Fri Jun 05, 2009 7:01 pm

PM sent.
It should sound like it isn't there!
There is a difference between hearing and listening...
Making life enjoyable through expensive electronics.
_________________
Carver: C-4000 & C-1 preamps, PSC-60 preamp/tuner, TX-11a tuner, M-400 (2), C-500, M-500, M-500t, M-500t Mk.II, A-500x, AL-III loudspeakers (2 pr.)
Sunfire:Theater Grand III processor, Ultimate Receiver, Cinema Grand Signature 400 ~ seven, True Subwoofer Mk. II, D-10 Subwoofer

Post Reply

Return to “CARVER Equipment Repair/Help Forum”