Tech Square

Technical and speculative discussion of amps, cables and other topics.

Return to Tech Square

Message Sort: Post Order or Asylum Reverse Threaded

C-J PF-R preamp: "All digital IC's are blown, not worth repairing"

146.115.68.191
Posted on September 20, 2012 at 10:47:23
WoodyWW
Audiophile

Posts: 41
Location: Southern NH
Joined: July 23, 2004
 3 months ago, during a thunderstorm, I was rushing around shutting down & unplugging everything in sight, but when I got to the PF-R, it was "lit up like a Christmas tree", meaning, all the front panel lights. Totally dis-functional.

Sent it off to C-J last June, & a couple of months later Ed called me & said it was "fried", but I couldn't get any more info than that, until they finally sent it back, & the (non) repair slip said: "All digital IC's are blown, not worth repairing".

I have almost no tech expertise at all, so....the only thing I could do might be to find a local repair shop, & pay more $$, on the off chance C-J doesn't know how to diagnose their own components.

Suggestions? Try to sell it as is for parts? The faceplate & the cabinet are in just about perfect condition.

TIA for any suggestions.....

 

Hide full thread outline!
    ...
My sincere sympathies...., posted on September 21, 2012 at 13:05:19
unclestu
Dealer

Posts: 5851
Joined: April 13, 2010
 It really hurts when something goes up like that: Perhaps your homeowner's insurance will cover?

Unfortunately, the PFR uses relays and a lot of digital switching in order to get the full function remote working. If all of those are blown, then just the labor alone to replace all those parts becomes astronomical. In addition I would guess that the power supply is also pranged as CJ uses IC regulators.

It is always good to have at least a surge protector on your circuits. You can never tell. I had an acquaintance who brought me a Power Wedge grumbling that it just failed after coming home from a trip to the local market. In opening up the unit, I found a 1/2 inch hole blown into the Corcom module from the voltage limiter which had arced from a lightning strike down the street. Considering that he had $6K worth of gear plugged into it, I'd sat it was cheap insurance.

Might be better to list on AA trader as a parts unit, after all, as you point out, it is a nice chassis.


Stu

 

RE: My sincere sympathies...., posted on September 22, 2012 at 08:18:46
WoodyWW
Audiophile

Posts: 41
Location: Southern NH
Joined: July 23, 2004
 Thanks Stu. I actually have a high deductable on my homeowner's insurance. I might ask if they offer any coverage specifically for electronics (like when you add special, additional coverage on silver, jewelry, & such) that I could add in the future.

2 questions if you have time: Do you think CJ gear in general is more susceptible to this sort of failure? Is ARC or Cary gear for instance more robust? Or is it more related to the CJ pre-amps with remotes?

Also, my house has an old 60 amp fuse box, & none of the outlets are grounded. Would surge protectors even work? (I am using a few right now).

Thanks again!


 

Surge.., posted on September 24, 2012 at 13:59:54
unclestu
Dealer

Posts: 5851
Joined: April 13, 2010
 protectors do work. Only trouble is that the fusible element is a one shot deal. You usually have to open up the protector occasionally to double check that it is still intact. There are a few which have an indicator light to show when the over voltage element has been tripped. That element can be changed and people like Digikey and Mouser sell them very cheaply.

To answer your first question, every manufacturer is equally susceptible. The fact of the matter is all integrated circuits are quite sensitive to voltage spikes. If your CJ was a pure tube unit, the damage would not have been so severe.

As an aside, NASA, still only uses 486 computer chips for their space probes, because the pentium chips are so susceptible to over voltage failure caused by cosmic ray strikes.

Grounding your panel and duplex would certainly significantly help also. In terms of long term piece of mind, upgrading your electricals may be more fruitful than the add on devices.

Good luck,

Stu

 

Lightning protection, posted on November 13, 2012 at 16:47:16
jea48
Audiophile

Posts: 6770
Joined: January 5, 2005
 Also, my house has an old 60 amp fuse box, & none of the outlets are grounded.




It might be a good idea to have an electrician check the earth ground for the electrical service.

Even though you do not have safety equipment grounds your electrical service is still connected to earth for lightning protection....

The earth connection could be broken (open), or badly corroded.



 

RE: C-J PF-R preamp: "All digital IC's are blown, not worth repairing", posted on November 22, 2012 at 20:07:28
pictureguy
Audiophile

Posts: 22597
Location: SoCal
Joined: October 19, 2008
 First, I'll agree.....get an electrician out there with a MEGGER to check your ground connection.

Next, price out a whole-house surge protector. maybe 400$ installed? I'd hope not much more.
You may want to find out how much to install or retrofit ALL grounded outlets. And while you're at it....you might consider an upgrade to 100 amp service. It will pay dividends to your stereo listening.......with that dedicated circuit you'll install at the same time.

Next, The device in point of use surge protectors.....outlet strips and the like....even higher end....are devices called MOVs = Metal Oxide Varisters.
They'll take a good bashing and DO NOT conduct until the conduction voltage is reached than they arc thru. They are connected hot to ground or hot to neutral. These devices DO wear out over time, even if not zapped bigtime. The repeated turn on surges eats into capactity and lifetime.

The good news is that MOVs are dirt cheap. A technician should be able to replace them in the event they've been zapped. The capacity is usually measured in Joules with each device being a part of the whole. You may need to replace several of 'em.


Too much is never enough

 

Lightning is totally un-predictable!, posted on February 18, 2013 at 02:57:35
grhughes
 It can enter a house in a number of ways, ground phone lines, cable tv coax lines, anything electrical connected to the house, old TV antennae can bring it in. If you have expensive gear then invest in a good isolation transformer/s that will handle your entire media system. Upgrade your 60amp panel to 200A modern standards and put s surge protector on critical circuits that service expensive computer, media gear and appliances. Get a surge protector that you can service and replace because the mercury diodes inside absorb the shock and expire afterward. A GFCI is not a surge protector. I've lost an oven element and a TV due to power going on and off. My hi-fi escaped because I have an isolation transformer and a surge protector on it.

I live in a rural area and rural electric co-ops are notorious for on-off spikes after power failures. Ray

 

Page processed in 0.027 seconds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]