Panasonic professional SVHS recorder AG-7350.
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- เผยแพร่เมื่อ 29 พ.ย. 2024
- Let's try to repair a Panasonic professional SVHS recorder from around 1993.
Audio and video transfers: www.video99.co...
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Music “Let It Run” with permission, copyright Cristie/MacFarlane.
I have the same vcr with alignment noise ( sonething like that) every 7 seconds... today i will replace these caps :) very thank you for this very informative video
Just replaced all caps on servo board... the issue is still present but soves by itself afetr 1 minute (something related to bad caps on power supply?) BTW everything seems fine, but audio is LOW ... and there is an HISS high frequency noise... removed audio/tracking head , cleaned, replaced, set correct alignment to have left and right at the same values... tracking data coming... but still this high pitch noise. (using the DOLBY filter make better the sound but removeing too much frequencies.) any hint about bad caps on A1 and A2 cards?
As obsolete these things may be, the amount of know how, engineering knowledge , crazy logistics needed to make these machines happen...I am at loss for words to explain the amazement I feel , I mean, just designing one of the ICs in this machine could very well be the task of a lifetime ..at least this is what I feel.
It is great to know a few of us share this appreciation !!
I know. In a previous life (so to speak) I was employed in the semiconductor industry, including being involved to some small extent in the design of ICs for TV and video.
maybe you can tell us about that experience in a future video ?
By the way, this was one hell of a repair job , great job mate !
@@rodrigobelinchon2982 I probably can't say much about that, but if you look up these two ICs you will get some idea: MV1817 and MV1822. I was the test engineer for those products, which meant writing the software which would test their analogue and digital processing on an ancient Teradyne J941 test system. Then there were also set top box ICs like the VP531 which were tested on LTX Synchromaster testers. All a very long time ago now.
will do , thank you !!
Nice machine and interesting fault finding process!
Hello, The empty slot is for a digital still frame module that has some memory and quite a lot of digital electronics for it, intended for medical and lab imaging. The model number for the machine fitted with this module is AG-7355 (a door and control from that will also fit your 7350 :P).
I have two 7350s and a 7355, I was donated a machine with a mere 30 hours on the head drum and it's been fantastic :D.
One of them had this fault, it ended up being the purple capacitor, one had this capacitor already leaking but no issues yet, replaced all of those anyway.
I've also advised about this fault to someone else here where it turned out to be the capcitor you ended up replacing.
My clue back then was that there was DC voltage where there shouldn't be, somewhere in that circuit.
Do also note that there is a ceramic hybrid IC on one of the video modules with SMT electrolytics that are very prone to leaking save for some very late units.
The power supplies have a 1µF 400V starter capacitor that drops in value over the years until it becomes so low that the power supply will no longer begin to operate, two machines I've worked on had this fault. I'd replace it just in case, even if it's good.
The fact that these power supplies aren't in stand-by unlike the domestic units means that the rest is very unproblematic. These are fantastic units.
Mode switch can cause loading problems, my 7355 had this. They are not possible to open and clean without distruction, but with some jerry rigging (tiny screw where the plastic welding point weas) you can do it anyway.
What a helpful bloke - I'd certainly use his dubbing service.
I've got an AG-7330, a very similar machine, not sure of the differences. It has the exact same fault as shown in the video, no time code or picture but if you leave it on for a while it will start to work once it's warmed up. I always suspected it was a capacitor fault but never looked into it further. I think I will dig it out and have a go at replacing them. Thanks for the informative video Colin!
It certainly sounds like the same fault so well worth investigating. A can of freezer and a hot air gun (mine was set to 100C) really helps.
Hello did you solve it? I have the same 7330 with this issue. But the caps are different from the caps in the video. Unfortunately I have no service manual for the 7330 to check, which caps it could be.
The "missing" board is indeed for the TBC which was used in the AG7750 recorder. The 7750 was a great machine and the best SVHS pictures I have ever seen. It utilised Luminance noise reduction, Chroma noise reduction and of course the TBC, so all that combined with the extra frequency response of SVHS made a great picture output. We had a lot of these machines when I worked at Foxsports in Sydney.
Interesting. I wonder how the numbering scheme went then since there was also a AG-7650 player with TBC, I have a couple of those and there would have been a recorder version. Did you find that Panasonic machines didn't have the best head life?
@@video99couk The AG7650 is the playback-only version of the 7750 judging by the service manuals floating around the web. I don't think the missing board has anything to do with those decks though, they're quite different internally. What I found in the past while digging is that there is a AG-7355, which looks very similar to the 7350, but has a digital frame store for storing one (or more, don't know) freeze frames. I presume that one has an extra board there, there's one video on yt of the 7355 on yt where you can spot a fourth board in that slot.
Got two of these 7350s here, one in pretty nice condition, and one that's pretty worn. The NiCD battery pack in one had started leaking, but thankfully I noticed before it leaked on anything. It works fine without it so I presume it's used for backing up timer settings or something.
@@analogvideochannel4612 Yes that makes sense, these models didn't have a TBC so a freeze-frame is one of the few things that could be added in the empty slot. The 7350 and 7650 are not very closely related. The play-only version of the 7350 is the 7150. I can barely think of a reason to have a battery backup. The 7350 doesn't seem to log head hours, doesn't have a timer, clock or tuner, so presumably only retains the tape position counter if it is powered down with a tape left in.
@@video99couk In my 7 years at Foxsports, I can only remember changing 3 or 4 video heads to these machines and we had about 20 (10 players/10 recorders). These machines were used nearly every day for editing and on-air playback, so for us at the time, the head life was good, but we did use Fuji SVHS tapes which were low wearing and produced the best pictures with almost zero dropouts. Our main machines were Digi-Beta and we had around 120 of those, I was the Senior Videotape Engineer at the time.
@@azmath2059 I have a AG-7750 and can vouch for it being a good machine. Head has done quite a lot of hours but still it's good. The TBC is excellent for sorting out home recordings but this machine will NOT play a commercial tape with copy protection so forget watching VHS movies on this which is a pity. It's also very quiet in operation. All that said a Betacam SP is better in quality without a doubt.
I rescued an AG-7350 yesterday. Cosmetically it seems alright but it has a sticker "Faulty electrolytic capacitor, moiré patterns in the picture. Not repaired" which doesn't sound too promising, especially seeing how difficult some caps seem to be to replace. I haven't tried plugging it in yet but might do so tomorrow.
Radiomuseum claims the 7350 was introduced in 1998, which can't be true if yours has a battery pack from 1993. That seems a lot more plausible to me anyway, 1998 seems quite late for S-VHS.
I couldn't help but notice a Techmoan mug sitting there. Stumbled on your channel the other day while researching the Sony EV-9000 and should I buy one off eBay with clicky playback - it seems I shouldn't. Now, Google finds you again - this time, looking info on the AG-7355 and specifically whether it has a TBC (it has digital freeze frame, so could). I've had this lying around for years and dug it out at the weekend to play with. At first I got only noise (even in trick modes, which probably use different heads). Tracking pulses all present & correct,. analog audio was fine, hifi audio sporadic and the rf meter very low. I cleaned the heads with a wet cleaning tape and it made no difference - at first. After about 10-15 minutes of noisy playback, the heads magically recovered and it now plays back amazingly well, in all modes. I was going to sell this on eBay because of the size and buy something smaller (a hi8/digital8 Walkman would be nice) but may just keep it as the picture quality is very good. And I haven't even tried as SVHS tape in it yet, must get one.. Btw, I saw a YT video one time of someone that 'manufactured' a missing bakelite knob for an old radio by making a soft silicone mould from one of the other knobs and casting a new knob in hard black pourable resin. The results were nothing short of extraordinary; surface texture perfect and even the tiny blemishes in the bakelite were there. You literally couldn't distinguish the clone from the original when placed side-by-side. I must try that later in the year, when it gets warm enough for resin to actually set! Great channel btw, I'm a patron of Techmoan, BigClive, Franlab etc. I'll add you to my patreonship at the weekend..
Well my ag-7350 Where the tape would not lock in, would just like no ctl pulse, RF Meter off tape was going up and down because it wasnt locking in. took a good clodse look at the caps in that area that you were hitting with the freeze spray, and found one that had green funk on the legs of it. C42 was the culprit. changed it and it works fine now.
Great job :-). I have two AG-8700 (8 heads with TBC) and wait for me hell all smd capacitors changement. For this machines are faulty elecrolyte caps normal, because working with inside hot temperature from power supply (after stable start about 30 - 35 grade celsia).
every single smd cap was dead.
Very good and very interesting video. I've certainly learned a very valuable lesson regarding the way capacitors have that habit of reforming after soldering and then passing test. It really explains a situation I've been in but couldn't ever explain. Thanks! Let me know the pot value, I'm going to be breaking an AG-7500 shortly so might be able to help.
Nice fault finding. I have the exact machine, and playing back SVHS tapes will not produce a picture. I'm guessing it too is suffering from aged / bad components. I will endeavour to repair it when I can get it out of my rack.
Nice vid , ive got the same SVHS recorder AG-7350 but it constantly gets error E-3 , Loading motor belt slipping is about the only lead i have .
Trying to figure that out on mine right now myself.
If one of these decks is operational will it play EP recorded tapes? Thanks for your time & expertise
Awesome video, such a professional service. Did you ever experienced famous E-5 error code in AG-7350? Seems that this is a mystery, since I cannot find the solution anywhere. Something prevents the reel motor from playing the tape.
I have loads of spares for these and 3 x 7750, 1 x 7350, 1x AG4700, 1 x LEITGH DPS-575 amongst other bits.
Great repair colin :-D
That gave you a good run around :-), pesky capacitors.
That chip must have been hanging on by it's finger nails (if it had them) with the bad caps, a slight capacitance drop and bye bye processing lol.
The plugs/sockets can be deceptive problems as well, the crimping goes bad :-(
The freezer spray really helped. I will miss my Maplin freezer spray.
Hello I have one of these and when plugged in it switches off after 2 secs do you think it’s a psu issue? Thanks great Video
The 7350 is a surprisingly robust machine compared with the 1970 and 1980. The 7350 shown here has one known problem with three or four bad capacitors on the capstan servo circuit. It will show this symptom as the tape counter not counting, and the tape will constantly go in and out of tracking. Signals from the control head are disabled.
Is this related to the AG 8700? Looks almost the same? That has TBC module. And lots of surface mount capacitors!
Yes I think it is the same chassis. Oh how we love changing SM capacitors...
Pretty much my favorite VHS machine. build quality is great. you really should just pull the auto head cleaner out. they have a tendency to disintegrate when they get old. can end up causing more damage and head clogs. It plays S-vhs as well as regular, picture is quite nice. One of panasonics better designs. 🤩
Help me what is error code e-7? Service manual is only up to E-6. After a few minutes it stops playing and displays the E-7 error code, until then it plays flawlessly.
Hello and greetings from Germany. I have an AG-7330 here with the same fault. Unfortunately the Manual is not available on the net to see which cap is faulty, because they different from the model in the video. Even if the IC3 is the same the caps are different... Did an other user solve the problem and can tell me which cap to change? Thanks.
Hallo, konntest du deinen Recorder reparieren? Habe gerade das selbe Problem.
hi @30:11 what de soldering iron do you use :) ? I cleaned the head on mine and it made an improvement with the IPA and played a little better so while this is my little project to try get it working again i might as well change some of the caps like you did, as they say only buy tools when you need them so.. i need them as have a few irons but looking at your video looks like it needs the de soldering sucker iron. The sound on mins is perfect and shame to just leave it would be nice to get it back to its glory.
I use this for desoldering: th-cam.com/video/Pi-3A9f3te0/w-d-xo.html
But it's not essential for all de-soldering work.
@@video99couk yup managed to pause your video on the gun to jot down the model no. also found the base station one, and on test its has more suck than this one so not sure what one to go for. Watching your video now :) on the review and fix.
Hi. I have a 7350 with the folowing problem when I insert a tape.
The tape is pulled in and lowered by the mechanism. The head starts to spin but there is no lacing. The lacing mechanism is completely dead.
After 2 seconds or so, the head stops spinning and the tape is ejected. There is no error message on display.
What I should start to investigate?
Thank you in advance for your advice.
First check to see if there's any voltage on the lacing motor. If so, it may be a mechanical jam up or bad motor. If not, then it's going to take a bit more serious investigation with the service manual.
Hi, I would really like to see the bottom side of this VCR mechanism.
If ever I have reason to get it in the workshop again, I'll certainly feature that. But at the moment it's in a stack of machines so it's not too easy to get to.
Good memories of this machine. We ran a pair of them with a Sony rm450 edit controller for news editing. About 5 edit bays. Why svhs for broadcast? Management were waiting for dvcpro and didn't want to spend full price for a betacam system. So for about a year we had the lowest video quality of anyone in the market lol. We were a new launch tv station. Lots of good memories of crash editing packages for reporters in time for the 5pm news show.
DVCPRO turned out not to be worth the wait, I suspect. Most DVCPRO decks are unreliable and didn't come with Sony levels of support. But would have looked better than SVHS for sure.
@@video99couk we had digital playback in master control at the time, that system was made by bts. they wanted to be all.digital at the time. This was back in 1996. Also it's convenient in news editing to be able to go many generations with less loss than analog. The important tapes always seemed to disappear at the most important time lol.
1 have one AG7750 PLAY/REC and one 7650 PLAY booth working but 7750 is working without output signal of audio
Hi and thanks forHi and thanks for your answer regarding the tape insert. The grease was gluey and prevented the mechanism for working.
I changed the grease, the lacing is working fine, but I have another problem: when I press play, the image appears on the screen but is still or freeze. Immediately the player stops and it tries to eject the tape but become stuck. The E5 error appear - Reel Lock trouble. Any advice in that matter?
Thank you in advance for your advice. your answer.
It's very hard to debug a problem by remote control. It could be a capstan drive fault, pinch roller not engaged, supply spool jammed, or another mechanical fault. You will have to look at it carefully.
@@video99couk Thank you!
Hi sir I just wondered if you could answer a question you say there is a switch to turn off the settings to isolate the battery . You couldn't tell me what settings does it actually affect if you switch it off ? Many thanks
You would have to look it up in the user or service manuals. Probably disconnecting the battery would make the machine forget the position of a tape which was left in during power cycling. Can't think what else it would be for, because I don't think these machines have a head hours meter (again check manuals).
@@video99couk ok thank you for your input I will look online for a service manual &Yes they do have a head hours counter it says mine has done 900 + hrs ........
I have one of these or very similar; when I put the tape in and press play, after a few seconds it stops automatically. Pressing play repeatedly just brings up the same issue repeatedly; play button lights up a few seconds but no picture appears and after a few seconds the stop button lights up automatically. Do you have any advice on why this might be?
You really need to diagnose the fault properly. It could be head drum motor or capstan not running, for example.
@@video99couk I opened the top cover and it seems although there's whirring like a motor trying to do something, the mechanism never actually move the tape into position to touch the spinning drum. You have any advice on that maybe? Something I need to grease up so it can move? :)
Great video. Thanks.
Interesting video my friend , would you know how much a machine like that would cost when it was first released ?
I don't know, but not cheap. The version with a timebase corrector would have been much more expensive, though, probably about £2000.
@@video99couk But they have capacitor cancer. This was the last model before that happened.
Would you happen to know if this PAL model can play NTSC as well? On the door it says both.
Sorry, I didn't try that. Most Panasonic PAL machines will play NTSC but not quite all.
Hello. Please tell me if you know how to view the operating time of the clock on the counter on the Panasonic AG-7350. Which buttons to press and in what order.
I don't know, but I suspect that information is not available on this machine. I would like to be proven wrong though.
@@video99couk Hello. I recently bought a Panasonic AG-7350, made around 1996. When loading the cassette, the cleaning roller jumps. The foam rubber on the roller has lost its elasticity and resembles plasticine. Should I delete it altogether? I can clean the video cylinder manually, I have experience.
@@video99couk Found. Information about the operating time of the clock is available through the menu and is displayed on the TV screen.
hmmm, the smell of old VCRs ...I can almost smell those toasty electronics :-)
Hi again. Investigating further the E5 error that I told you in previous comment, I found out that when the tape is insert, between pinch roller and capstan shaft it is a gap about 0.5 mm.
Is there any way to reduce that gap?
Thank you!
It's probably not getting into the fully laced position. There could be many causes for that, including a bad mode switch or mechanical failure. It needs careful investigation.
@@video99couk Investigating the mode switch as you said, I noticed a pinch solenoid on top of mode switch. This solenoid is pressing more on pinch roller which engage the pinch roller on capstan shaft, into the fully laced position. This solenoid was stuck. After I unstuck the solenoid, everything is working well.
Do you repair these for the public or is it just your own machines? I have one that no longer loads tape due to the loading mechanism being damaged.
Thanks
Alas I can't take on repairs, I have a backlog of my own machines to work on.
I have the same recorder that I got from England a few years back.
It is still ok but it is inclined to go into fast forward mode after playing for a while. ...Any suggestions? We use it to convert VHS to Digital Media and would like to get a second one but in Australia there is none. Do you sell any that you have repaired?
I would probably suspect the mode switch needs cleaning, which will be underneath the deck somewhere. Another possibility is that the opto sensors are contaminated or have been knocked out of alignment. I don't sell machines often, I tend to collect video equipment, too much of it!
250 for one of this is a good price? someone is selling one in near mint condition, the seller says it was serviced by oficial panasonic techinicians a frew years ago and is working perfect, with low usage. Also you can 3D print a door and a knoob as replacement parts.
That's probably a reasonable price for an SVHS machine which includes a TBC. I have a 3D printer but was able to get original parts eventually.
Nice machine. Saw a new one on Ebay go for over US$1575. VHS Hi-Fi is supposedly better audio quality than reel-to-reel or cassette. And those VU meters, input level knobs, and time code are a rarity on a VCR. Besides audio, there's still uses for a machine like this, such as giving video a dated effect.
It's never worth that much. Beta HiFi is better again than VHS HiFi. But both will suffer from clicks or crackles if there are tape dropouts.
Hello. I will gladly see a movie on how to fix VCR when there is no video and audio signal
I've had that problem on a NV-HS950, see my video about the K-series chassis, the notes to that one list the component which caused it. But of course the cause will vary hugely from one machine to another.
10:50 Linear stereo heads on hifi machines would be useful to play tapes with linear stereo only (such as commercial tapes or home recordings from the era when only linear stereo existed). The manufacturers didn't bother to give consumers that option for cost reasons. That said I've never in my life come across a tape with linear stereo only, so it's a theoretical problem.
I doubt that linear stereo tracks were ever provided on commercial tape releases on VHS, beta or V2000. It would be interesting to prove that with a magnetic viewer.
@@video99couk I'm positive that commercial tapes were released with Hifi AND linear stereo, because I have some where it says so on the box. Examples are "Television" by the Pet Shop Boys, and "1974-1982" by ABBA (both VHS). I'm not positive that there were releases with linear stereo only, I'm just assuming that there must have been. A record company who wanted to release a music video on VHS pre-1985 surely would have made sure it used the best audio format available at the time, don't you think?
@@xaverlustig3581 All NTSC VHS tapes were stereo on both the Hi-Fi and linear tracks up to the very end- even though very few machines can play the linear tracks in stereo.
Throw that NiCad away. I just lost a board on one of my 3 x AG7350s because of the battery leaking. All 3 batteries were dead anyway and they are only needed for the memory in the front panel.
Top!
Hello Sir, Im lucky enough to have a AG 7355 machine which is working great.. I was wondering if you have found a knob ...! My machine has the same knob missing unfortunately,,, if you know were I can get one ☝️ that would be awesome, thanks very much, Carlo from Perth Western Australia, Cheers.
Yes I was sent the cosmetic parts to finish this machine recently: th-cam.com/video/EEEIXsn0vh0/w-d-xo.html
If you email me via my web site, I could see if the sender might have another.
Ok thanks,
Must take alot of room.
Hii