Just picked up a Panasonic PV-1730 Hi-Fi VCR

[vortalexfan]

OK, so I looked at the Service Data and it looks like IC2007 is the one that controls the motor control board and was the one you were talking about possibly being bad am I correct?

[Ed in Tx]

Originally Posted by vortalexfan

OK, so I looked at the Service Data and it looks like IC2007 is the one that controls the motor control board and was the one you were talking about possibly being bad am I correct?

It's possible but without doing some testing with a service manual, scope and DVM don't get me to lying!

[vortalexfan]

Originally Posted by Ed in Tx

It's possible but without doing some testing with a service manual, scope and DVM don't get me to lying!

I'm not going to, I'm planning on taking a look at it more closely after I get off work tonight.

Since I now have my 'scope figured out how to work it I'll see if I can figure out what's what on the VCR.

[Ed in Tx]

Originally Posted by vortalexfan

I'm not going to, I'm planning on taking a look at it more closely after I get off work tonight.

Since I now have my 'scope figured out how to work it I'll see if I can figure out what's what on the VCR.

Be sure to check for a shorted electrolytic capacitor somewhere in that motor drive circuit too, could be something as simple as that. As old as it is that's a possibility.

[vortalexfan]

Originally Posted by Ed in Tx

Be sure to check for a shorted electrolytic capacitor somewhere in that motor drive circuit too, could be something as simple as that. As old as it is that's a possibility.

Well I looked through the service data and I found 4 electrolytics in particular that seem suspect in the motor drive circuit that could be causing my issue, C18 (C1118 in the Sam's), C30, C32, and C34 (C2530, C2532, and C2534 respectively in the Sam's) that are all in the 11.9V Source (15V) rail, and the 12V Source rails for the supply and take up reel motors.

One in particular looked kind of out of place (it looked a little newer than the rest of the capacitors in the unit and also it was a higher capacitance rating than what's called out in the Sam's), which is C30 (C2530) which is supposed to be a 100 µF 16V but instead had a 470 µF 16V capacitor in that spot, which unless there was some sort of design change made to the unit that wasn't reflected in the Sam's (or that was reflected in the Sam's) I think someone installed the wrong size capacitor in there, which I'm apted to think that someone put the wrong size capacitor in there because as I said the capacitor was a completely different style of capacitor than the rest of the capacitors in there.

[Ed in Tx]

Originally Posted by vortalexfan

Well I looked through the service data and I found 4 electrolytics in particular that seem suspect in the motor drive circuit that could be causing my issue, C18 (C1118 in the Sam's), C30, C32, and C34 (C2530, C2532, and C2534 respectively in the Sam's) that are all in the 11.9V Source (15V) rail, and the 12V Source rails for the supply and take up reel motors.

One in particular looked kind of out of place (it looked a little newer than the rest of the capacitors in the unit and also it was a higher capacitance rating than what's called out in the Sam's), which is C30 (C2530) which is supposed to be a 100 µF 16V but instead had a 470 µF 16V capacitor in that spot, which unless there was some sort of design change made to the unit that wasn't reflected in the Sam's (or that was reflected in the Sam's) I think someone installed the wrong size capacitor in there, which I'm apted to think that someone put the wrong size capacitor in there because as I said the capacitor was a completely different style of capacitor than the rest of the capacitors in there.

Re-read your post. It's probably OK depending where it is in the circuitry. I wouldn't necessarily trust Sam's as gospel either! Might have been a change during production.

If I had that machine first thing I would be doing is checking every electrolytic in it with my ESR meter. I actually have two, one I used at the shop and the other for home use, it's that important and useful.

[Ed in Tx]

Won't let be attach two files! What the ...??!

OK I see what's going on. I already attached that one in another thread a while back.

Another pic (right side) testing the Hi-fi audio board from an old JVC VCR. Those old surface mount caps were notorious for failing.

[vortalexfan]

Originally Posted by Ed in Tx

Re-read your post. It's probably OK depending where it is in the circuitry. I wouldn't necessarily trust Sam's as gospel either! Might have been a change during production.

If I had that machine first thing I would be doing is checking every electrolytic in it with my ESR meter. I actually have two, one I used at the shop and the other for home use, it's that important and useful.

Unfortunately my ESR Meter died recently (the LCD Display won't come on anymore) and it was one of those "kit" units that you could get on ebay for $10 (the one that could come either cased or uncased.)

The Sam's for this VCR is from 1987 and my VCR is from 1984...