The Official AVS Dish DTVPal DVR Topic! - Page 610 - AVS Forum
Forum Jump: 
 74Likes
Reply
 
Thread Tools
post #18271 of 18294 Old 08-06-2014, 02:39 PM
Advanced Member
 
ed_in_tx's Avatar
 
Join Date: May 2007
Location: NW Dallas TX
Posts: 990
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 26 Post(s)
Liked: 53
Nice work! On the Nichicon capacitors you used, in the apparent high stress application, I would recommend using the Low Impedance 105° rated caps, UPW1A222MPD6 for the 2200uFd/10V caps, UPW1E221MPD for the 220uFd/25V caps, mostly the "UPW" series of electrolytics.

Last edited by ed_in_tx; 08-06-2014 at 02:48 PM.
ed_in_tx is offline  
Sponsored Links
Advertisement
 
post #18272 of 18294 Old 08-06-2014, 03:05 PM
Member
 
Hankw69's Avatar
 
Join Date: Sep 2007
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 18
More Repair Info....

For those that may have similar freezing/locking-up problems with their PAL, the attached jpg shows the four electrolytic caps I replaced that fixed my F/L problems.... Caps numbered 1 & 2 had noticeable tops bulging and the two others were only guilty by association - being in the same proximity as the bad boys.(Not scientific, but, it signifies circuitry that exhibits a higher load for the caps to work with). Caps 2 and the other just below it are believed to be involved with main power input filtering to the large PC Board, affecting the main power bus with the others scattered throughout for local filtering of power for the components in their near proximity.. As stated earlier, cap # 1 was the most likely suspect as its degraded performance would be a definite problem for the LSI chip. I will continue to monitor my PAL performance and will be on the lookout for the obvious bulging cap tops.... Although your units caps may not all need to be replaced, I would suggest at least to change any bulging tops and the larger caps that would necessarily work under a larger load, the caps on the separate power supply board especially. I will probably just keep an eye on performance and as my spares will not last indefinitely, they should be around for any failures in the near future....
Attached Images
File Type: jpg PAL PCB-mod.jpg (366.3 KB, 52 views)
Hankw69 is offline  
post #18273 of 18294 Old 08-06-2014, 03:12 PM
Member
 
Hankw69's Avatar
 
Join Date: Sep 2007
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 18
Quote:
Originally Posted by ed_in_tx View Post
Nice work! On the Nichicon capacitors you used, in the apparent high stress application, I would recommend using the Low Impedance 105° rated caps, UPW1A222MPD6 for the 2200uFd/10V caps, UPW1E221MPD for the 220uFd/25V caps, mostly the "UPW" series of electrolytics.
Agreed, your suggestion to use caps with a higher temp rating would be of benefit. For most if not all, I tried to select Lifetime/Temp caps with a 10000 Hour/105' temp range and I believe most do. In any event, with most any cap replacement with today's production quality, they will be of a better quality than what is mass-stuffed into production pcb's... :-) Will probably outlast me... almost...
Hankw69 is offline  
post #18274 of 18294 Old 08-07-2014, 06:15 AM
AVS Special Member
 
LenL's Avatar
 
Join Date: Nov 2008
Location: Randolph, NJ, 725' above sea level, 30 miles west of ESB
Posts: 1,464
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 107
Smile Great Info Guys!

I have never soldered tiny electronics but the info you provided almost makes me want to give it a try.... if and when one or both of my DTVPals should die due to failed capacitors!
LenL is offline  
post #18275 of 18294 Old 08-07-2014, 06:51 AM
AVS Special Member
 
JHBrandt's Avatar
 
Join Date: Apr 2008
Location: S. Garland, TX
Posts: 1,628
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 44 Post(s)
Liked: 153
You'll probably want to replace the capacitors before the Pal completely dies. If you wait until then it may be too late.

I say that because I had a 23" LCD TV die, and when I took it apart I saw the same bulging capacitor problem.

So I ordered a set of replacement capacitors and replaced them all. Didn't help. The power supply was completely fried.

Luckily I found a replacement PS for a reasonable cost, and it resurrected my TV. (To be safe, I replaced all the capacitors on the new PS preemptively, since it had come with the same brand capacitors as the original PS.) But finding a replacement PS board for a Pal might be almost impossible.

So I'd probably check the capacitors every time I opened up the Pal for cleaning, or if it started acting erratically. Try to catch the problem and fix it before any permanent damage is done.
JHBrandt is offline  
post #18276 of 18294 Old 08-07-2014, 09:43 AM
Advanced Member
 
trp2525's Avatar
 
Join Date: May 2008
Posts: 674
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked: 58
Quote:
Originally Posted by JHBrandt View Post
.....But finding a replacement PS board for a Pal might be almost impossible.....
Here's a "new" power supply board for the DTVPal DVR/CM-7000PAL DVR on eBay for $40 plus $8 shipping: http://www.ebay.com/itm/Power-Supply...-/131228529594
trp2525 is offline  
post #18277 of 18294 Old 08-09-2014, 10:57 AM
Member
 
Hankw69's Avatar
 
Join Date: Sep 2007
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 18
MORE Good Info - For the Technically Inclined....

Received my goodie box of 34 new caps a couple of days ago. Now deciding when a few hours of cap R&R will happen. My initial guess was correct, this LSI chip under the cover shield is truly the "brain" of all video processing and interfacing to the outside world. Cap #1 was definitely the problem; its labeled value is 820 uF @ 6.3V and measured ~250 uF with my Fluke 179 meter. Its next door buddy marked 220uF@ 10V measured 236 uF,. still measuring ok, but, it is still on the replacement list. Cap #2 labeled 2200 uF @ 10V, measured 5710 uF . I am not certain what this high measurement indicates, but, certainly above the nominal 10-20% tolerance.. #2 's buddy, labeled 1200uF @ 35V measured 1166 uF, seemingly ok but will also be replaced. The above measurements were not observed with a high priced LCR meter, but my 200 buck Fluke that gave good indications as to the general health of the caps. Tried to paste the pdf but too large. So here is the link for the curious...

http://www.alldatasheet.com/datashee...S/STI7109.html

As stated earlier, by the time electrolytic caps exhibit faulty operation noticed by, in my case, of pixellating/freezing, the damage is under way. When operating to specification they provide DC filtration, a smoothing of the rectified AC power. Regulator chips provide a relatively smooth DC voltage and when the filter caps hit the internally stage of a "SHORT" failure, they can and do overload the regulator chips that feed them. A lot of time resulting in that nice burn smell of a charred PCB. In the cases that the caps fail in an "OPEN" state, the solid state devices that rely on a smooth DC input voltage, are hit with an "overload"-if you will- of AC ripple. This drives these devices into a mode of operation that they were not designed for and often-times fail. To provide the mostly digital and some times analog outputs, they REQUIRE a nice level/smooth DC voltage. So, in "my reality", most or all of solid state devices, IC's too, would probably function just about forever. It is the weak link of electrolytic caps that are the major destroyers of ALL of our electronic gear....
Hankw69 is offline  
post #18278 of 18294 Old 08-09-2014, 11:08 AM
Advanced Member
 
ed_in_tx's Avatar
 
Join Date: May 2007
Location: NW Dallas TX
Posts: 990
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 26 Post(s)
Liked: 53
Quote:
Originally Posted by Hankw69 View Post
... Cap #2 labeled 2200 uF @ 10V, measured 5710 uF . I am not certain what this high measurement indicates, but, certainly above the nominal 10-20% tolerance.. #2 's buddy, labeled 1200uF @ 35V measured 1166 uF, seemingly ok but will also be replaced.
I've seen this before with caps that have really high ESR. The Sencore "capacitor analyzer" I used at the old P.O.E. would display unusually high capacitance with high internal resistance, which had me fooled until I got an ESR meter.

The 1200 uF measuring low, it was very likely well on the + side of tolerance when it was new. So good decision there to replace it.
Hankw69 likes this.
ed_in_tx is offline  
post #18279 of 18294 Old 08-09-2014, 08:45 PM
Senior Member
 
visualsensation's Avatar
 
Join Date: Mar 2008
Location: Milwaukee, WI
Posts: 234
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 11
Quote:
Originally Posted by JHBrandt View Post
That may be a new, unreported bug. Over 100 subchannels? That's impressive (if it weren't causing you problems).

It sounds as if the Pal is storing so many channels it's actually running out of flash memory to store timers. Milwaukee may be an especially tough case because you'll get Chicago's stations and possibly others as well during tropo.

If that's the case, the only solution that comes to mind is to prevent the fringe channels from being received at all. Otherwise they'll take up memory even if you hide or delete them, and they'll eventually come back and fill up your memory again even after a factory defaults reset.

Not sure of the best way to do that, but a very directional antenna might help. Could you post a radar plot for your address from tvfool.com so we can all see what you're dealing with?
Yea, it's ridiculous. It's been picking up channels from Green Bay, Grand Rapids, South Bend, Chicago, Rockford, Madison, Dubuque, and even a station from Iowa City. On top of that, at least four of the local stations have assigned at least 7 subchannels each, most of which don't broadcast anything. I've thought about a directional antenna, but haven't gotten around to it yet.
visualsensation is offline  
post #18280 of 18294 Old 08-10-2014, 05:13 PM
AVS Special Member
 
JHBrandt's Avatar
 
Join Date: Apr 2008
Location: S. Garland, TX
Posts: 1,628
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 44 Post(s)
Liked: 153
DFW has one LP station with 9 SD subchannels, and another with one HD and 6 SD subchannels! The picture quality of all those SD channels is pretty low; 19-odd Mb/s just isn't enough bandwidth for all those channels.

I think Trip knows of a station or two with 12 or more subchannels
phildaant likes this.
JHBrandt is offline  
post #18281 of 18294 Old 08-10-2014, 05:27 PM
AVS Special Member
 
phildaant's Avatar
 
Join Date: Nov 2005
Location: An Ant Farm
Posts: 2,481
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 167 Post(s)
Liked: 73
Post

Quote:
Originally Posted by JHBrandt View Post
DFW has one LP station with 9 SD subchannels, and another with one HD and 6 SD subchannels! The picture quality of all those SD channels is pretty low; 19-odd Mb/s just isn't enough bandwidth for all those channels.

I think Trip knows of a station or two with 12 or more subchannels
Oh yeah? In Los Angeles (L.A.), KVHD-LD has 13 subchannels! :O I noticed my DTVPal DVR doesn't even detect new channels. I have to do it from scratch to find them!
phildaant is online now  
post #18282 of 18294 Old 08-10-2014, 06:28 PM
AVS Special Member
 
Aleron Ives's Avatar
 
Join Date: Oct 2009
Posts: 2,607
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 161 Post(s)
Liked: 293
KAXT in Santa Clara, California has 20 subchannels (12 video, 8 audio).
phildaant likes this.
Aleron Ives is offline  
post #18283 of 18294 Old 08-10-2014, 06:34 PM
AVS Special Member
 
phildaant's Avatar
 
Join Date: Nov 2005
Location: An Ant Farm
Posts: 2,481
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 167 Post(s)
Liked: 73
Quote:
Originally Posted by Aleron Ives View Post
KAXT in Santa Clara, California has 20 subchannels (12 video, 8 audio).
Dang. Audio doesn't use that much bandwidth compared to videos though.
phildaant is online now  
post #18284 of 18294 Old 08-17-2014, 05:44 PM
Advanced Member
 
ed_in_tx's Avatar
 
Join Date: May 2007
Location: NW Dallas TX
Posts: 990
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 26 Post(s)
Liked: 53
I see someone "won" on e-bay a malfunctioning DTVPal DVR for $53. I had a starting bid on it for $10 but no more, figuring I might learn something if I got it. Anyone here get it?
ed_in_tx is offline  
post #18285 of 18294 Old 08-17-2014, 08:36 PM
AVS Special Member
 
P Smith's Avatar
 
Join Date: Apr 2003
Location: Mediterranean Sea
Posts: 1,951
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 127
I see someone buying such TR50s, dismantle them and selling parts: a case, a fan, PSU, HDD, etc ... but main board. Perhaps has no skills/experience/parts/equipment for fix.
P Smith is offline  
post #18286 of 18294 Old 08-18-2014, 08:55 AM
Member
 
Hankw69's Avatar
 
Join Date: Sep 2007
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 18
Quote:
Originally Posted by ed_in_tx View Post
I see someone "won" on e-bay a malfunctioning DTVPal DVR for $53. I had a starting bid on it for $10 but no more, figuring I might learn something if I got it. Anyone here get it?
I tried but stopped at 15 bucks and change.... I just knew that the problem was with bad electrolytics... Could have fixed for 19 bucks in caps-total replacement. BUT, my OWN unit gave me a good talking to about how the caps I have had "His" name on them ... :-)
AND when to find the time????
Hankw69 is offline  
post #18287 of 18294 Old 08-18-2014, 01:19 PM
AVS Special Member
 
P Smith's Avatar
 
Join Date: Apr 2003
Location: Mediterranean Sea
Posts: 1,951
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 127
and again it was your luck ... I have many with same symptoms, but capacitors
P Smith is offline  
post #18288 of 18294 Old 08-18-2014, 02:33 PM
Member
 
Hankw69's Avatar
 
Join Date: Sep 2007
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 18
Quote:
Originally Posted by P Smith View Post
and again it was your luck ... I have many with same symptoms, but capacitors

Just for kicks, did you try replacing the two caps (820uF @ 6.3v & 220uF @ 10v)?? (under the ~2" shield cover where our "LSI buddy lives"... The 820 in mine was a bulger and I truly believe this guy was causing my freezing/pixilation/audio issues. The box has played steady as a rock for almost a couple of weeks. FYI I do not ever turn off, although the standby is "always on"... As our banter of the "LSI" chip has calmed, this chip is really the key component with decoding, synching, converting, and most any other important function that need to happen to get from antenna to the TV screen. I would be curios of your results after you shotgunned these two out....
Hankw69 is offline  
post #18289 of 18294 Old 08-19-2014, 03:41 AM
AVS Special Member
 
P Smith's Avatar
 
Join Date: Apr 2003
Location: Mediterranean Sea
Posts: 1,951
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 127
I did replace them on a couple occasions; to surprise you - I did measures of C/ESR and found no issue. "LSI" acronym would be good if you don't know what is the chip; so , for correctness sake, pleas start name it correctly: STi7109. What the chip is capable I know from HW/SW manuals what you could read too if you're in it.
I will tell you more, I'm not the guy who are changing bulged capacitors. I'm EE and have/use scopes, DMM, generators etc to check signals. I did check the rails where the capacitors and seen results on screen of digital scope (500 MHz).

Perhaps, it's not my style of troubleshooting and repairs as you try to drug me in ....
P Smith is offline  
post #18290 of 18294 Old 08-19-2014, 09:20 AM
Member
 
Hankw69's Avatar
 
Join Date: Sep 2007
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 18
Quote:
Originally Posted by P Smith View Post
I did replace them on a couple occasions; to surprise you - I did measures of C/ESR and found no issue. "LSI" acronym would be good if you don't know what is the chip; so , for correctness sake, pleas start name it correctly: STi7109.
OK-Got it...

What the chip is capable I know from HW/SW manuals what you could read too if you're in it.
I AM into it and have read the info at the link before I posted it - http://www.alldatasheet.com/datashee...S/STI7109.html

I will tell you more, I'm not the guy who are changing bulged capacitors. I'm EE and have/use scopes, DMM, generators etc to check signals. I did check the rails where the capacitors and seen results on screen of digital scope (500 MHz).
My past life was Digital Hardware Design Engineer - KSC FL... Have a good knowledge base for what I speak... If you have noticed "bulgers" and did not change them because they may have measured good, well, this is where we certainly differ-for sure...

Perhaps, it's not my style of troubleshooting and repairs as you try to drug me in ....
My theory is that IF a part has changed shape or shows sign of an issue - I REPLACE IT-PERIOD...
Hankw69 is offline  
post #18291 of 18294 Old 08-19-2014, 11:03 AM
Senior Member
 
wiscojim's Avatar
 
Join Date: Mar 2009
Posts: 242
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 95
Quote:
Originally Posted by Hankw69 View Post
My theory is that IF a part has changed shape or shows sign of an issue - I REPLACE IT-PERIOD...
Settle down, you're making a fool of yourself, no matter what education and experience you've had in the past.

.
Pete-N2 likes this.
wiscojim is offline  
post #18292 of 18294 Old 08-19-2014, 12:48 PM
Advanced Member
 
Pete-N2's Avatar
 
Join Date: Jun 2009
Location: Lynchburg, VA
Posts: 552
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Liked: 21
Location: Mediterranean Sea

P. Smith -- How long have you been back in Greece?
Pete-N2 is offline  
post #18293 of 18294 Old 08-19-2014, 01:50 PM
Member
 
Hankw69's Avatar
 
Join Date: Sep 2007
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 18
Quote:
Originally Posted by wiscojim View Post
Settle down, you're making a fool of yourself, no matter what education and experience you've had in the past.

.
I find it hard to believe that there is the opinion that if a part, in this case, an electrolytic cap, can be considered OK to leave in a circuit when its appearance indicates the start of a failure that may not be kind to the electronics it is installed in.. I.E. leaking electrolyte, an actual bursting of the tops, which now-a-days the occurrence has been minimized by the scoring marks on the tops. Yea, maybe you are right, Am I really the fool to spend 2-3 bucks on several caps that are "bulgers", which may very indeed protect a piece of electronics that may cost hundreds??? No, it is the fool who will not replace such components that are "screaming" to be noticed and replaced....
Hankw69 is offline  
post #18294 of 18294 Old 08-19-2014, 11:13 PM
AVS Special Member
 
P Smith's Avatar
 
Join Date: Apr 2003
Location: Mediterranean Sea
Posts: 1,951
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 127
I'm agree with you - need to replace them while you are doing any fix. It's just common practice of repairs. Yes, you are not a fool, it must be done anyway.

My point was the issue with TR50 (by symptoms) is more serious and usually not that easy to fix it. Telling that by experience of fixing the devices for a few years.
It was your luck (again).
P Smith is offline  
Reply HDTV Recorders

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off