Friday 13th fail. Sony AC-L10B power adaptor for Digital 8 camcorder.

[@A2Z1Two3]

credit to you for posting a 'failure to fix' when it would be easy to hide it away never to see the light of day

[@fluxjunkie6645]

I would check and change the opto isolator .I have had them go faulty and causing instability in the feedback circuit.

[@more.power.]

Thank you a great episode its all about the learning for me.

[@cashawX10]

Interesting, I had a similar failure on the same power supply a few years back. I had to source a replacement from Sony for an exorbitant price. Also, thanks for all your videos which KZbin is suggesting to me on a daily basis. They are great and entertaining, informative background fillers whilst I am working, also I think I am the only one of my friends and family who still has a VHS recorder below their TV... my friends and family think I am weird. 🤣It would be interesting to know if you still have "daily drivers" or if you want to get away from them after working ánd fixing them all day.

[@video99couk]

Like most people we use Sky Q or similar for recording TV these days, not video tape. I do still however still use a CRT TV in my workshop.

[@barrieshepherd7694]

I don't feel so bad now about my PSU fix failures 😂 Main thing is you tried and made the judgement call.

[@Thepaddster]

Those tamper resistant screws are actually less effective in my experience than a standard torx. Your less likely to have the bit, but any appropriate sized flathead can lever off the centre pin (which is often quite brittle and can be broken off anyway) and be used to unscrew it as normal! "defeated by a simple little power supply" is unfair. Power supplies are increasingly complex, especially Sony ones and they aren't built to be repaired at all! Most new ones are sealed shut by heating the plastic, such is the drive to make them consumables.

[@Knaeckebrotsaege]

first suspect for a pulsing SMPS would be the startup cap (usually 47µF 16-50V) on the primary side (next to the KA7552 SMPS controller in this case, and identical to the failed one on the secondary you replaced), which i don't think was even tested here, let alone replaced. If it goes bad, the PSU tries to start, the control IC gets starved of power and shuts down, rinse and repeat. When the problem isn't as bad yet, the PSU might just take a little longer to turn on when supplied with AC, which progresses into several seconds of "ticking" as the PSU tries to start up but fails till it eventually still manages to do it (usually helped by warmer temperatures), to the point where it doesn't start up anymore and just pulses permanently with the output being all over the place, if there's any at all

[@video99couk]

All capacitors were tested.

[@timetec]

Suspicious looking solder joint on the centre pin of IC202 (3-pin TL431 voltage reference IC)...

[@TTVEaGMXde]

It's not a Trick, it's a Mitsumi. If it's a Supplier Part for Sony, they might have no Circuit Diagram at all. I would have treated the Q201 SMD Transistor on the Underside with Cold Spray, because solder baths are always dangerous for SMD Transistors.

[@zx8401ztv]

Any luck on the dead 9v psu? Make sure the three lead Tl431 shunt regulator near the output is ok, and it should also go down to the opto coupler to control the switchmode .

[@jamesaward1953]

Great, learned a lot just subscribed your channel.

[@SFtheGreat]

Speaking of digitizing V/Hi8, did you notice a discolouration appearing as a greenish stripe along the right edge of the image, when digitizing to DV file?

[@video99couk]

This is well known, it was due to a compromise Sony made in their PAL camcorders. The stripe is supposed to be in the overscan area so not visible on a TV, but you see it on a video capture. There's also head switching noise at the bottom, typical of all domestic formats. So I drop the captured picture by 1% and expand it by 3%, sometimes shifting right by 1% too. Then it fills the frame nicely.

[@SFtheGreat]

@@video99couk It doesn't appear, when the machine is in passthrough mode. Do you know what is causing this to happen specifically? Head switching noise I've witnessed on many tapes now can be very minimal, on one occasion it was only one line, that disappeared when playing in VLC with deinterlacing turned on.

[@amatorev]

Good morning, my VX-1 Pro camera stopped recording videos correctly, the image has flickering and colored streaks, I cleaned the head and the problem remains only in recording, when playing other tapes the camera will play correctly, I had changed all the capacitors a year ago and I had cleaned the boards properly there were not many leaks.. the camera worked fine sometimes but when I didn't use the camera often when I put it to play the tape would spin and the motor sounded like tired as I worked on 1 hour the camera the problem went away, to emphasize that in the two DC converters the camera has throoghole capacitors which I have not changed I suspect they are the ones causing the problem !!

[@video99couk]

Those capacitors might well be the problem. Sometimes you can test capacitors in-situ with a ESR meter, but it depends if the circuitry around presents a load to the meter.

[@amatorev]

hmm i opened the dc converter it there are sanyo capacitors in purple color i didn't see any leakage but they may have short circuited or dried out due to aging i will measure them and change them later i hope that is the problem and it will be solved,

[@amatorev]

@@video99couk I changed all the capacitors in both converters, cleaned the boards with alcohol for any leaks from the old capacitors, also cleaned all the cables and connectors on the deck of the cassette player, re-soldered the boards for any bad connections, cleaned the brown and the problem remains the same what do you think could be happening? see the two videos I uploaded kzbin.info/www/bejne/jn60gaJvns9mh6s kzbin.info/www/bejne/sIi7hqOwoc-ar9U

[@feedback-loop]

I would suggest (carefully!) measuring the ripple on the power rail of the primary controller chip. I think you gave up too easily. :)

[@video99couk]

The reason I knew it wasn't ripple in the primary, is that the pumping action carried on for some seconds after the input was disconnected. During this time, there cannot be any ripple. Hence we had eliminated the entire primary side.

[@markhodgson2348]

Easier to get another PSU and change the output plug /socket

[@TTVEaGMXde]

@@markhodgson2348 A inexpensive 8.4V 1.5A SPS is not easy to find, and with a 9V power supply, a diode in the circuit would dissipate 1W of heat

[@pierrejeanf.dupuis4150]

A for effort. I dispose of about 50 power supplies a day.

[@jamesbennettmusic]

Shame. Send it to Clive for a reverse engineer!

[@video99couk]

It's too complex, there's a lot of surface mount stuff on there. It would take days, if possible.

[@markhodgson2348]

Modern technology

[@cod4Rlp]

I'm thinking you did this for the video / for fun because there's no chance this is worth all the time of attempting to fix it when they can be purchased for under £20.

[@video99couk]

Well I thought it would be a quick repair good for a KZbin Short. But it was neither.

[@Knaeckebrotsaege]

Considering the replacement PSUs are 99% not original and tend to also be a danger to your device with _zero_ noise filtering or any sort of safety features, it *definitely is* worth it to try and fix an original PSU that was built to a standard... with the standard not being 3 miles under a chinese dump

[@cod4Rlp]

@@Knaeckebrotsaege you can buy the original used as a replacement but I agree with the the replacement adapter quality

[@cod4Rlp]

@@Knaeckebrotsaege surely if the input was going to permantly damage the device it should just blow a fuse though right?