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  #81  
04-20-2019, 11:17 PM
RS456 RS456 is offline
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Another issue with the same VCR. The head now spins up really fast like a computer hard drive. What could be the problem? Few minutes ago it was playing just fine with the Y/C board from other VCR. It started as soon as I reinserted its own Y/C board which was playing like scrambled signal just yesturday. Now its spinning like that even with the working Y/C board from the other VCR.
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  #82  
04-21-2019, 12:27 AM
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Originally Posted by RS456 View Post
Another issue with the same VCR. The head now spins up really fast like a computer hard drive. What could be the problem? Few minutes ago it was playing just fine with the Y/C board from other VCR. It started as soon as I reinserted its own Y/C board which was playing like scrambled signal just yesturday. Now its spinning like that even with the working Y/C board from the other VCR.
Could this be a problem where a capacitor in Power Supply going bad? I remember bumping into the vcr before the problem started but it only moved on the table.
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  #83  
04-21-2019, 03:00 AM
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It seems the issue is caused by the 5 pin brown connector (2) near the vcr drum in front of the power supply. I disconnected practically everything in the tape deck except that connector and it still spins at the hard drive like speeds. Did something in one of the 6 cards go bad? I am assuming the problem might be in the servo card. Please correct me if I am wrong.
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  #84  
04-25-2019, 12:57 AM
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I just got the MESR-100 in circuit capacitor tester. How do I know if a electrolytic capacitor is bad with this meter? Some are saying good if less than the checked capacitor say for example 10uF as marked but other capacitors of the same size are saying good if less than 47uF (these are marked 10uF). Are these other capacitors bad marked as 10uF but saying good if less than 47uF? How do I check ceramic capacitors? Can I use the MESR-100 to check them? Also capacitors I am getting no reading at all (OL displayed no matter what) can I consider them 100% bad?
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  #85  
04-25-2019, 07:25 AM
dpalomaki dpalomaki is offline
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I think you are a bit over your head in this repair process in that you don't have the necessary understanding of what the components are, how they work, and what the test gear can and can't tell you. And this is why the repair services charge what they do.

The ESR meter measures the effective "resistance" between two points to a small 100kHz current. The expected and acceptable "resistance' will depend on the capacitor size, voltage rating, construction, and chemistry. The meter you have has a table on the face that gives a go/no-go figure for common electrolytic sizes and voltages. This is a guide, not an absolute, and the configuration and design requirements ofr the circuit you are measuring, can effect this. (Some application may call for a lower ESR capacitor than listed in the guide table. Other components in the circuit may distort the reading. This is where understanding the circuit and existing part parameters is an important factor.)

This meter is designed to work with electrolytic capacitors, and is not appropriate for small value capacitors such as most ceramics, and in some cases, where components are in parallel, or where a coil or transformer is in the circuit between the two points. If the capacitor rating is not in the range covered by the table don't bother with it.

The physical size of a capacitor loosely correlates with its values; higher mfd and higher voltage typically required a larger can (in step increments) for the same type of capacitor but a different brand or other rating (e.g., temperature, ESR) factors may result in a different physical size.
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  #86  
04-25-2019, 08:56 AM
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Its a good learning experience for me. So basically you are saying MESR-100 is for Electrolytic capacitors only and I shouldn't bother with smd ceramic capacitors? But what about the Electrolytic Capacitors that I am getting no reading on? OL no matter what. Those I can consider bad or its not completely discharged yet to get a reading? This specific VCR has more issues than the others. The other two were completely fixed with just changing the SMD electrolytic capacitors. This one I changed even the radial ones and got a picture finally but now gone again to the distorted cable picture.
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  #87  
04-25-2019, 09:18 AM
dpalomaki dpalomaki is offline
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Remove from the circuit the electrolytic caps that test high and you can give them a second test.
They likely are bad.
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  #88  
04-25-2019, 12:03 PM
hodgey hodgey is offline
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I'm also just getting into using an ESR meter (Peak ESR70) and noticed the same. It didn't really work for the ceramics (non-SMD), at least in-circuit.
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  #89  
04-25-2019, 04:50 PM
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What about electrolytic capacitors I am getting good if less than 47 uF when the marking on the capacitor is 10uF? Those good or I have to desoder them and check again? Resistance on it is much lower than what is on the table on the meter for 10uF at a given voltage.
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  #90  
04-25-2019, 07:46 PM
dpalomaki dpalomaki is offline
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Quote:
What about electrolytic capacitors I am getting good if less than 47 uF when the marking on the capacitor is 10uF?
I have no idea what you mean.

The ESR meter does not read out in mfd.
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  #91  
04-25-2019, 08:33 PM
sevarre sevarre is offline
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Quote:
Originally Posted by RS456 View Post
What about electrolytic capacitors I am getting good if less than 47 uF when the marking on the capacitor is 10uF? Those good or I have to desoder them and check again? Resistance on it is much lower than what is on the table on the meter for 10uF at a given voltage.
I am also planning on starting a 1980P repair soon and think I am just gonna replace all electrolytics outright. I know there are a TON (like 228?) but I figure since Iím already in there doing it I might as well take the time to replace them all. Plus I believe in general electrolytics are known for their notorious eventual failure, so probably worth it in the long run.
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  #92  
04-25-2019, 11:59 PM
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Quote:
Originally Posted by dpalomaki View Post
I have no idea what you mean.

The ESR meter does not read out in mfd.
What mine shows is the resistance and on the bottom line it said good if < C uF. Most of them show C exactly as what is written on the capacitor but a few show significantly higher value than what is written on the capacitor but the shown resistance is within the given threshold according to the chart.

Quote:
Originally Posted by sevarrei View Post
I am also planning on starting a 1980P repair soon and think I am just gonna replace all electrolytics outright. I know there are a TON (like 228?) but I figure since Iím already in there doing it I might as well take the time to replace them all. Plus I believe in general electrolytics are known for their notorious eventual failure, so probably worth it in the long run.

Read more: http://www.digitalfaq.com/forum/newreply.php?do=newreply&p=61067#ixzz5mApp8YUA
I replaced all the electrolytic capacitors in the problem causing board. I think there were 37-70 on that board. I just had a few more issues and some hiccups with this VCR.
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  #93  
04-26-2019, 07:30 AM
dpalomaki dpalomaki is offline
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A 10 mfd cap will have a much higher allowable ESR than a 47 mfd for the same voltage rating.

What it is telling you is that the ESR would be OK for caps smaller than 47 mfd. Because your cap is less than 47 mfd, the ESR is OK.

Quote:
...I am just gonna replace all electrolytics outright....
Probably not necessary and a lot more work, but that is your decision. Some caps will be very difficult to reach. Do the Y/C board and for other boards replace any that test marginal or bad. The timer board has a history of some failing caps. Other boards not so much.
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  #94  
04-26-2019, 10:44 AM
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So with MESR-100 can I safely assume an electrolytic capacitor is good If it says "good if less than a given 'capacitor value'" is greater than the actual capacitor value (ex. 10uF is the capacitor value and meter says good it less than 47uF)?

Also the other issue I now am facing with this troubling VCR (issue wasn't there before it suddenly started) is the VCR drum suddenly started spinning like a computer hard drive (very fast). Do you happen to have any idea where the problem might be? I suspected maybe it is the servo card. In that the 220uF capacitor is border bad according to this meter. It said good if less than 200uF instead of 220 or more. Any other place I might have to look at to fix this issue? I disconnected everything except the 4-5 pin orange connector to the tape deck from main board and it still spins like that as soon as I plug it in.
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  #95  
04-26-2019, 07:22 PM
sevarre sevarre is offline
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Originally Posted by dpalomaki View Post
Probably not necessary and a lot more work, but that is your decision. Some caps will be very difficult to reach. Do the Y/C board and for other boards replace any that test marginal or bad. The timer board has a history of some failing caps. Other boards not so much.
Yes I think you are correct. Finally got around to taking apart the 1980P yesterday and I think I will stick with just recapping the Y/C board, timer board, and maybe the rear input/output board. It's nice to be able to take the particular boards off the main board and just work on that, instead of having the whole thing to work with while soldering. However, they were NOT EASY to remove from the main board at all.
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  #96  
04-27-2019, 02:14 AM
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Originally Posted by sevarre View Post
Yes I think you are correct. Finally got around to taking apart the 1980P yesterday and I think I will stick with just recapping the Y/C board, timer board, and maybe the rear input/output board. It's nice to be able to take the particular boards off the main board and just work on that, instead of having the whole thing to work with while soldering. However, they were NOT EASY to remove from the main board at all.
To remove the main board is not easy. They made it in such a way you can not easily repair it. To easily access the main board you have to remove the front panel and boards and disconnect the the bottom plugs to those boards and remove the 4 screws in the back by the output ports. With this the whole main board and output ports panel lifts out. I don't think you have to cap anything in the output panel board.

The timer board on this problematic VCR is fixed. I just recapped the radial leaded electrolytic capacitors with new ones but I wasn't able to find which was actually a bad cap. All of them tested out out ok to good. Maybe they are the two that snapped off. There is one cap behind the LCD on the bottom corner which is easy to miss. Also the one on the top left corner of the LCD is not a pF capacitor even though it kind of looks like one. It is an 220uH inductor which needs no replacement unless it snapped off like what happened to me. For that this is a good replacement if it happens to you.
https://www.mouser.com/ProductDetail...78148S1224J000
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  #97  
04-27-2019, 01:53 PM
sevarre sevarre is offline
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Quote:
Originally Posted by RS456 View Post
There is one cap behind the LCD on the bottom corner which is easy to miss. Also the one on the top left corner of the LCD is not a pF capacitor even though it kind of looks like one. It is an 220uH inductor which needs no replacement unless it snapped off like what happened to me. For that this is a good replacement if it happens to you.
https://www.mouser.com/ProductDetail...78148S1224J000
Interesting, thanks for this info. I will update on my progress. I am thinking about getting a hot air station. I have a Weller WES51, which is awesome, but am thinking I will need something more geared towards SMD work. I have a couple bad mobo's I plan on practicing on.
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  #98  
04-27-2019, 05:37 PM
RS456 RS456 is offline
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Quote:
Originally Posted by sevarre View Post
Interesting, thanks for this info. I will update on my progress. I am thinking about getting a hot air station. I have a Weller WES51, which is awesome, but am thinking I will need something more geared towards SMD work. I have a couple bad mobo's I plan on practicing on.
I don't know about that. It might blow away the smd electrolytic capacitors instead of soldering them on plus there is a tight spot on the Y/C board where those capacitors are very close to the socket connecting to the main board. With a hot air gun there is a risk of melting it to the point of bending but with it there is another option that opened up. You can remove the socket before you remove and recap the board. If you ask me I think a fine solder tip is more than enough to get this job done.
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  #99  
05-06-2019, 03:41 AM
sevarre sevarre is offline
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ALRIGHT!! Finished recap of Y/C board and timer board and things are looking GREAT! On power up, the LCD display turned on right away... was very happy to see that as the LCD was previously completely dead- so that is fixed. Also, I was getting awful barber pole diagonal color lines previously and now that seems to be pretty much be completely gone. There are still some issues it seems, but I will investigate those later (machine very squeaky and other more mechanical-y issues). Just feels awesome to see some actual results. I will upload some before/after samples either to this thread or to my initial thread that detailed my initial issue with diagonal rainbow color lines (barber pole).

RS456, you are correct that I didn’t need to use a hot air station. I ended up taking your advice and simply got an extremely fine tip for my iron and that seemed to do the job. I gotta admit my soldering skills are pretty crap, so we’ll see how long this “repair” actually lasts. Some of the SMD cap connections are pretty terrible.

Also taking apart the 1980P machine itself is pretty aggravating. Actually insanely aggravating. I finally got all the random connectors and FPC connector things plugged in to the correct spot, but it probably took nearly as long to do all of that correctly as it did to do the actual recap. Also I initially broke off what appears to be a ground connector from the main board to the chassis, but I was able to resolder pretty nicely.

For the actual recap I replaced all electrolytics on the Y/C board (besides the three caps on the small auxiliary chip labeled VEP03D52, I didn’t see it and had already ordered parts!) and all electrolytics on Timer board besides that awful one below the LCD (think it is labeled C03 for that board). All in all was about 14 hours for me from the absolute start to the absolute end. Was not fun, but was also not “brain surgery” as I have seen it over-dramatically referred to on the videohelp forums. Definitely more difficult than the 1974 Pioneer stereo receiver that served as my first recap project.

RS456, what is your current progress/status? Is the machine still spinning like a hard drive? Did you ensure all of those little connectors are made from the main board to the K mechanism assembly?
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  #100  
05-06-2019, 05:49 AM
dpalomaki dpalomaki is offline
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Congratulations!
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