NAD 7240PE

G

Glenn Barry

Guest
HI All,

I've got a NAD 7240PE which has low output level from the Pre-Amp on the
left channel. I dont yet have a schematic/repair manual, but I'm working on
that.
In the meantime has anyone out there had experience repairing one of these
that could point me in the direction of which components to check/replace.

Any and all tips appreciated

Thanks

Glenn
 
Check if turning the soft clipping switch on the back on or off makes the
difference. In any case have a look inside near that switch and you'll see
four half watt resistors, they are usually in a sad state and ofthen gone
open or quite high in value.


"Glenn Barry" <glennrbarry@yahoo.com> wrote in message
news:401dfd40$0$18303$afc38c87@news.optusnet.com.au...
HI All,

I've got a NAD 7240PE which has low output level from the Pre-Amp on the
left channel. I dont yet have a schematic/repair manual, but I'm working
on
that.
In the meantime has anyone out there had experience repairing one of these
that could point me in the direction of which components to check/replace.

Any and all tips appreciated

Thanks

Glenn
Click to expand...
 
Thanks for the tip, but it doesn't make any difference to the output with
the switch in either position.

I just checked the rersistors, assuming I have the right ones - These are
the smaller ones to the right hand side of the switch when viewed from the
front R415 - 429 Ohms, R 417 1370 Ohms, R419 1370 Ohms and R421 428 Ohms,
I'm new to electronics and learning as I go, these seem to be about right

R413, R414, R423 and R424 - The four larger ones with the diodes in between
are all coming in between 4.8 and 5 KOhms which from the colours doesn't
seem to agree. The bands seem look to be Grey Red Red and Gold.

Glenn

"Bodgey" <ihate@spam.com> wrote in message
news:dQnTb.39486$Wa.12703@news-server.bigpond.net.au...
Check if turning the soft clipping switch on the back on or off makes the
difference. In any case have a look inside near that switch and you'll see
four half watt resistors, they are usually in a sad state and ofthen gone
open or quite high in value.


"Glenn Barry" <glennrbarry@yahoo.com> wrote in message
news:401dfd40$0$18303$afc38c87@news.optusnet.com.au...
HI All,

I've got a NAD 7240PE which has low output level from the Pre-Amp on the
left channel. I dont yet have a schematic/repair manual, but I'm working
on
that.
In the meantime has anyone out there had experience repairing one of
these
that could point me in the direction of which components to
check/replace.

Any and all tips appreciated

Thanks

Glenn
Click to expand...
 
If there isn't smoke & flames pouring out of it, it's a miraculously healthy 7240PE. Every
retail guy I've ever known referred to the "PE" designation as meaning "Purchase Extinguisher"
or "Probable Explosions". That has got to be one of the most terrifyingly badly built &
flammable receivers ever made. My advice is - Run away!

--
Stephen Sank, Owner & Ribbon Mic Restorer
Talking Dog Transducer Company
http://stephensank.com
5517 Carmelita Drive N.E.
Albuquerque, New Mexico [87111]
505-332-0336
Auth. Nakamichi & McIntosh servicer
Payments preferred through Paypal.com
"Glenn Barry" <glennrbarry@yahoo.com> wrote in message
news:401dfd40$0$18303$afc38c87@news.optusnet.com.au...
HI All,

I've got a NAD 7240PE which has low output level from the Pre-Amp on the
left channel. I dont yet have a schematic/repair manual, but I'm working on
that.
In the meantime has anyone out there had experience repairing one of these
that could point me in the direction of which components to check/replace.

Any and all tips appreciated

Thanks

Glenn
Click to expand...
 
I think they were OK when they were new - they just haven't aged well. The
browned, heated board areas, and the resulting legion of bad caps.
They also had bad resistors and caps in the soft-clip, and of course dirty
controls, one of which could be the OP's problem.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Stephen Sank" <bk11@thuntek.net> wrote in message
news:bvmp97$tmq$1@reader2.nmix.net...
If there isn't smoke & flames pouring out of it, it's a miraculously
healthy 7240PE. Every
retail guy I've ever known referred to the "PE" designation as meaning
"Purchase Extinguisher"
or "Probable Explosions". That has got to be one of the most terrifyingly
badly built &
flammable receivers ever made. My advice is - Run away!

--
Stephen Sank, Owner & Ribbon Mic Restorer
Talking Dog Transducer Company
http://stephensank.com
5517 Carmelita Drive N.E.
Albuquerque, New Mexico [87111]
505-332-0336
Auth. Nakamichi & McIntosh servicer
Payments preferred through Paypal.com
"Glenn Barry" <glennrbarry@yahoo.com> wrote in message
news:401dfd40$0$18303$afc38c87@news.optusnet.com.au...
HI All,

I've got a NAD 7240PE which has low output level from the Pre-Amp on the
left channel. I dont yet have a schematic/repair manual, but I'm working
on
that.
In the meantime has anyone out there had experience repairing one of
these
that could point me in the direction of which components to
check/replace.

Any and all tips appreciated

Thanks

Glenn
Click to expand...
 
The biggest problem was the 5 watts/ch worth of heatsink for 40w/ch of power amp(downhill in a
hurricane, of course), pretty much guaranteeing amp failure if pushed even a little bit hard.
Then there was the tiny 1amp rectifier bridge for the high-voltage section of the amp's "power
envelope" power supply, with it's switching transistors having 2w sinks on them. The several
dealers I knew at the time said literally 3/4 of them or more were returned DOA within days or
weeks of purchase. It really amazes me that any of them are still working. The only piece of
audio gear more frighteningly bad was the old Carver cube, which was only very slightly less
likely to have flames coming out of it than a gas stove.

--
Stephen Sank, Owner & Ribbon Mic Restorer
Talking Dog Transducer Company
http://stephensank.com
5517 Carmelita Drive N.E.
Albuquerque, New Mexico [87111]
505-332-0336
Auth. Nakamichi & McIntosh servicer
Payments preferred through Paypal.com
"Mark D. Zacharias" <mzacharias@yis.us> wrote in message
news:bvo36h$ud83t$1@ID-180484.news.uni-berlin.de...
I think they were OK when they were new - they just haven't aged well. The
browned, heated board areas, and the resulting legion of bad caps.
They also had bad resistors and caps in the soft-clip, and of course dirty
controls, one of which could be the OP's problem.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Stephen Sank" <bk11@thuntek.net> wrote in message
news:bvmp97$tmq$1@reader2.nmix.net...
If there isn't smoke & flames pouring out of it, it's a miraculously
healthy 7240PE. Every
retail guy I've ever known referred to the "PE" designation as meaning
"Purchase Extinguisher"
or "Probable Explosions". That has got to be one of the most terrifyingly
badly built &
flammable receivers ever made. My advice is - Run away!

--
Stephen Sank, Owner & Ribbon Mic Restorer
Talking Dog Transducer Company
http://stephensank.com
5517 Carmelita Drive N.E.
Albuquerque, New Mexico [87111]
505-332-0336
Auth. Nakamichi & McIntosh servicer
Payments preferred through Paypal.com
"Glenn Barry" <glennrbarry@yahoo.com> wrote in message
news:401dfd40$0$18303$afc38c87@news.optusnet.com.au...
HI All,

I've got a NAD 7240PE which has low output level from the Pre-Amp on the
left channel. I dont yet have a schematic/repair manual, but I'm working
on
that.
In the meantime has anyone out there had experience repairing one of
these
that could point me in the direction of which components to
check/replace.

Any and all tips appreciated

Thanks

Glenn
Click to expand...
 
Not running away, not yet anyway,

I've got a Service menual on it's way to me, in the meantime does anyone
know what the values of Caps C301 and C302.
The two are both greencaps but I'm not sure which one is the correct value,
C301 has .15j stamped on it and C302 has 154j. They're both in the path from
the Bass EQ to the volume and balance controls for each channel.

Thanks

Glenn

"Stephen Sank" <bk11@thuntek.net> wrote in message
news:bvp9bg$t0b$1@reader2.nmix.net...
The biggest problem was the 5 watts/ch worth of heatsink for 40w/ch of
power amp(downhill in a
hurricane, of course), pretty much guaranteeing amp failure if pushed even
a little bit hard.
Then there was the tiny 1amp rectifier bridge for the high-voltage section
of the amp's "power
envelope" power supply, with it's switching transistors having 2w sinks on
them. The several
dealers I knew at the time said literally 3/4 of them or more were
returned DOA within days or
weeks of purchase. It really amazes me that any of them are still
working. The only piece of
audio gear more frighteningly bad was the old Carver cube, which was only
very slightly less
likely to have flames coming out of it than a gas stove.

--
Stephen Sank, Owner & Ribbon Mic Restorer
Talking Dog Transducer Company
http://stephensank.com
5517 Carmelita Drive N.E.
Albuquerque, New Mexico [87111]
505-332-0336
Auth. Nakamichi & McIntosh servicer
Payments preferred through Paypal.com
"Mark D. Zacharias" <mzacharias@yis.us> wrote in message
news:bvo36h$ud83t$1@ID-180484.news.uni-berlin.de...
I think they were OK when they were new - they just haven't aged well.
The
browned, heated board areas, and the resulting legion of bad caps.
They also had bad resistors and caps in the soft-clip, and of course
dirty
controls, one of which could be the OP's problem.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Stephen Sank" <bk11@thuntek.net> wrote in message
news:bvmp97$tmq$1@reader2.nmix.net...
If there isn't smoke & flames pouring out of it, it's a miraculously
healthy 7240PE. Every
retail guy I've ever known referred to the "PE" designation as meaning
"Purchase Extinguisher"
or "Probable Explosions". That has got to be one of the most
terrifyingly
badly built &
flammable receivers ever made. My advice is - Run away!

--
Stephen Sank, Owner & Ribbon Mic Restorer
Talking Dog Transducer Company
http://stephensank.com
5517 Carmelita Drive N.E.
Albuquerque, New Mexico [87111]
505-332-0336
Auth. Nakamichi & McIntosh servicer
Payments preferred through Paypal.com
"Glenn Barry" <glennrbarry@yahoo.com> wrote in message
news:401dfd40$0$18303$afc38c87@news.optusnet.com.au...
HI All,

I've got a NAD 7240PE which has low output level from the Pre-Amp on
the
left channel. I dont yet have a schematic/repair manual, but I'm
working
on
that.
In the meantime has anyone out there had experience repairing one of
these
that could point me in the direction of which components to
check/replace.

Any and all tips appreciated

Thanks

Glenn
Click to expand...
 
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