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Channel Master CM-7000 Digital to Analog Converter - Page 49

post #1441 of 1483
Quote:
Originally Posted by Whitebar View Post

I looked at the circuit and there is no ESD/voltage surge protection.

Just out of curiosity, what would such an esd/surge protection circuit feature?
post #1442 of 1483
Quote:
Originally Posted by blue_z View Post


Whitebar:
Are you testing the caps with an ESR meter?
(I only had to replace 3 bad caps in the power supply to repair a unit, and ending up paying double/triple price from Fry's for a quick repair.)

Regards

I use an RCL meter to check the caps. This provides both the capacitance and the impedance values.
post #1443 of 1483
Quote:
Originally Posted by NeilPeart View Post

Just out of curiosity, what would such an esd/surge protection circuit feature?

This is typically a TVS (transient voltage suppressor) diode array to clamp the ethernet transceiver pins to an acceptable range. Here is a link to a page about ethernet ESD protection from one of many manufacturers.
post #1444 of 1483
Thanks for the update - I had no idea 10/100 and GigE would require different solutions.
post #1445 of 1483
Excellent, the drummer from Rush is here!
post #1446 of 1483
post #1447 of 1483
^^^if I lived near that CM I know where I'd be going tonight
post #1448 of 1483
Quote:
Originally Posted by Floydage View Post

Excellent, the drummer from Rush is here!

Bon Scott and Bob Crane both post on this forum, too, and I thought they were dead.
post #1449 of 1483
Hehehe to all of ya!

A $10 RCA still NIB popped up today, same region (Lewisville, TX). Seeing more Zeniths and such but $30-ish range.
post #1450 of 1483
I have two of the Channel Master CM-7000 units that have the red light problem. They were purchased under the coupon program in, I believe, 2009, but not plugged in until 2010. They were then run continually. The first one died about 6 months ago, and the second one died today.

I just took the second unit apart and measured the voltage with the power supply hooked up to the logic board (under load). I am getting 13.90V, 5.43V, and 3.27V. I have no way to measure the AC ripple. I will attempt a capacitor replacement and report back. The first unit is in a closet somewhere - if I can find it, I will measure and attempt a repair on it also. Since I have to mail order the caps, I can save on shipping if I do them both at the same time.

If anyone is keeping track of this stuff, the CM-7000 that died today is S/N 70002122090610.rolleyes.gif
post #1451 of 1483
I have repaired about twenty of them. From what I have seen there is no pattern to the serial numbers of the units that are failing. All have had the same revision power supply and logic board. I have seen two different die revisions of the processor IC, two different revisions of software and three different build dates.

Make sure you get good quality low ESR caps. Besides the power supply caps, you will need to replace E5 and E6 (both 33uf 35v) on the logic board. These are difficult to remove and replace because of the inner ground plane that makes a very good heat sink.
post #1452 of 1483
I'm moving discussion from another thread into here.

I've had a CM-7000 for a few years but I haven't used it much. Recently I tested it again, thinking I might cancel my cable subscription. The CM seems to work well at first, but it loses a number of stations after it's been on for a while, beginning with KTVU. After about 30 minutes, the picture starts to pixellate and the sound drops out. Eventually, it completely loses the signal.

If I turn the CM off for a while, it will get the station again, but as the signal fluctuates (as displayed via INFO) it trends downward until it hits the 30s and finally loses the signal completely again.

A couple folks on the other thread suggested I swap the CM with a DigitalStream I have connected to another TV & antenna; I did so, and the symptoms followed the box. Then I tried Floydage's suggestion of cutting power while the unit was on, which he says does a hard reset. My channels were still there afterward, and I waited more than 10 seconds before plugging back in, so I'm not sure what was reset, but it didn't help. I also tried a factory reset as described in the manual. This also had no effect.

I've tried the diagnostic screen mentioned in this thread. The unit passed all the tests most of the time, but it did fail the RAM test once.

KTVU isn't the only channel affected. After KTVU goes, a number of the others do, too, but KPIX and KMTP, for example are still going strong long after KTVU has disappeared.

Does this sound like it could be the early symptoms of the capacitor failure that's been discussed on this thread? Whitebar, if you're reading this, are you still offering to do cap replacements?

I'm mainly interested in keeping the CM around to use with my Panasonic Showstopper--it's been a while since I was researching this, but I remember it was one of the better boxes for that purpose. If there's something else these days that's better...or better yet, a modern DVR with built-in digital tuner and no subscription fee, I'm open to suggestions.
post #1453 of 1483
@WhiteBar. I recently sent two of the cm7000 units to you for repair. Big Thanks to you. They are working great.
post #1454 of 1483
Quote:
Originally Posted by ewilen View Post

Does this sound like it could be the early symptoms of the capacitor failure that's been discussed on this thread? Whitebar, if you're reading this, are you still offering to do cap replacements?

Yes that sounds like the caps on the logic board. And yes I am still doing cap replacements. Send me a PM for additional information.
post #1455 of 1483
Quote:
Originally Posted by jvvh5897 View Post


RE:

Channel Master D2A box


Put in a header for the jtag port and used jtag_p to dump the 2Meg flash and 8 Meg of RAM. The main part of the bin is gzip compressed, so that is part of what takes so long for this box to come up. Code is st20c1 and IDA Pro can disassemble that--not well, but not all that bad.


Would post the dumps but they are too big for the limit on zip.
Could you please post pinout of the connector (J5) ?
post #1456 of 1483
jvvh5897 hasn't posted on AVS in almost a year and a half, unless he's has subscribed to this thread I doubt he'll see your question smile.gif
post #1457 of 1483
Forgot that I even joined here.

As I recall the pinout of the connector was marked on the board. I just followed the silkscreen info. Haven't done anymore work on the dump since last post or so.
post #1458 of 1483
Hi,

Does anyone have more specifics that would help to order the 33uf capacitors, like Digikey part numbers?

Thanks
post #1459 of 1483
Quote:
Originally Posted by doggiemoon View Post

Hi,

Does anyone have more specifics that would help to order the 33uf capacitors, like Digikey part numbers?

Thanks

Digikey # P14434-ND Panasonic # EEU-FR1V330 CAP ALUM 33UF 35V 20% RADIAL
Mouser will also have this part.
post #1460 of 1483
Thread Starter 
How do you change the password inputted by a previous user on a used CM-7000? Without being able to decode the password, I cannot change many of the preferences settings.
post #1461 of 1483
Quote:
Originally Posted by seatacboy View Post

How do you change the password inputted by a previous user on a used CM-7000? Without being able to decode the password, I cannot change many of the preferences settings.

See if there's something under Lock, otherwise try a factory reset. Crummy manual is no help but does list reset password along with change password as a 'feature' on the Parental Lock page (of course the manual doesn't say how to do any of this mad.gif ).
post #1462 of 1483
FWIW: CM7000 User Manual, pg9 says to enter "0000" into the password field to reset to DEFAULT:
http://worldwidesatellites.com/cm-7000_manual.pdf

If that doesn't work, suggest you call C-M Support and see what they tell you.

BTW: There is a 10-pin test socket on the circuit board where I see "RST", "TRST" & "GND" labels that MIGHT be Reset (and maybe Total Reset)...but I wouldn't want to try them without verifying with C-M first:
http://cdn.avsforum.com/2/2c/2c6e161a_vbattach105535.jpeg
http://www.avsforum.com/t/1004274/channel-master-cm-7000-digital-to-analog-converter/30#post_13457349
post #1463 of 1483
Quote:
Originally Posted by holl_ands View Post

FWIW: CM7000 User Manual, pg9 says to enter "0000" into the password field to reset to DEFAULT:

I think you're absolutely correct per what it says under DEFAULTS. Yet confusing how they say "Restores setting to factory default settings." then go on about resetting the password (i.e. I think they're talking about two different things - restoring the box to factory default settings and resetting the password to 0000).

Man that manual beats the pants off the POS manual that came with my boxes which is mostly a bullet/feature list with very little 'how to' or description. Looks like I got an outline that the lead engineer gave to a subordinate to complete. eek.gif
post #1464 of 1483
BTW: There is a 10-pin test socket on the circuit board where I see "RST", "TRST" & "GND" labels that MIGHT be Reset (and maybe Total Reset)...but I wouldn't want to try them without verifying with C-M first:
http://cdn.avsforum.com/2/2c/2c6e161a_vbattach105535.jpeg

That 10 pin test socket is the JTAG test connector. It will not reset the password or defaults.
post #1465 of 1483
Anything come of implementing coaxial digital audio out on a CM-7000? (I saw something on the subject per holl_ands' 3rd link above).
post #1466 of 1483
I had not heard of the coaxial digital audio and never looked at that part of the circuit. All the parts were intentionally missing so I knew it was not causing the RED light problem,
I did take a quick look tonight. It does go to the missing parts in his photo. I did not trace it out but I suspect it may run from there to the STV0373 which also has some missing parts around it. Problem is I could not find any datasheet, pin out listing or schematics using the part.
post #1467 of 1483
Quote:
Originally Posted by Whitebar View Post

I had not heard of the coaxial digital audio and never looked at that part of the circuit. All the parts were intentionally missing so I knew it was not causing the RED light problem,
I did take a quick look tonight. It does go to the missing parts in his photo. I did not trace it out but I suspect it may run from there to the STV0373 which also has some missing parts around it. Problem is I could not find any datasheet, pin out listing or schematics using the part.

OK, thanks. holl_ands had asked in a post a few down from the one referenced in that link but I didn't dig any deeper than that. From what you found it's probably missing the required parts but otherwise may be possible assuming it doesn't need to be activated in software.
post #1468 of 1483
Thread Starter 
My CM-7000 works really well, but I do not possess the original CM remote, which I understand wasn't particularly good anyway. I have programmed an RCA universal remote and it satisfactorily controls most functions. One thing I cannot seem to do, though, is adjust the volume level of the CM-7000. My box is connected via the S-Video video input and the related audio input for S-Video (composite RCA cables). The volume level is very, very low and often I have to turn the TV set's volume way up, which can be jarring when I change video sources.

Compounding this, I can't find anywhere on the CM-7000's user menu where I can adjust the volume settings, or change audio output type from stereo to mono. Any thoughts on this, or am I stuck with very low audio output levels when using this box?
post #1469 of 1483
Quote:
Originally Posted by seatacboy View Post

My CM-7000 works really well, but I do not possess the original CM remote, which I understand wasn't particularly good anyway. I have programmed an RCA universal remote and it satisfactorily controls most functions. One thing I cannot seem to do, though, is adjust the volume level of the CM-7000. My box is connected via the S-Video video input and the related audio input for S-Video (composite RCA cables). The volume level is very, very low and often I have to turn the TV set's volume way up, which can be jarring when I change video sources.

Compounding this, I can't find anywhere on the CM-7000's user menu where I can adjust the volume settings, or change audio output type from stereo to mono. Any thoughts on this, or am I stuck with very low audio output levels when using this box?

It's been awhile for me but I don't think I had any problem with my u-remotes. Is your RCA programmed via a Pioneer cable box code or does it have a specific code for a CM converter box?
post #1470 of 1483
Thread Starter 
Quote:
Originally Posted by Floydage View Post

It's been awhile for me but I don't think I had any problem with my u-remotes. Is your RCA programmed via a Pioneer cable box code or does it have a specific code for a CM converter box?
My RCA U-remote had a specific CM converter box code. Is the Pioneer code one for a cable-TV box or something like that - I know there was not a Pioneer CECB (or "DTC" as RCA calls it).

Anyway, the volume level using S-video connections is very low, and the CM7000 does not respond when I click the volume up-and-down control.
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