Sony SL-C5 Betamax video repair - part 3 

They really are.

I feel your pain with carrying the C5 - I once liberated a mid-70s 22" TV from disposal from the local TV repair shop. I was 15 years old and I carried it a quarter of a mile back home - crazy! I ended up having to stop every few meters! They were surprisingly reliable mostly being let down by belts and those servo caps.

Çok güzel bir ani

Really loving this comment - apologies for the delay in reply but I've been seriously thinking about the best way to help you out as you are actually so close to sorting the issue. On that bottom board - if you put a meter across the pin the supply goes to and ground, do you get a very low resistance? My guess is you have a shorted cap somewhere. What if you disconnect the bottom board interconnects - does that change that value? Ultimately you'll need to isolate each part of the circuit to work out where the excess current draw is. Do you have a manual? i did consider maybe asking to do a collab and repair your machine remotely - might you be up for that?

@@MrBetaByte Many thanks for the reply, I can’t recall off the top of my head which pin it was we had found the short on, in the end we’d got the bottom board totally isolated from the rest of the machine. The resistance was very low, we tried putting a supply to that pin only using a external power supply and it was drawing around 4amps but nothing was getting hot/burnt. We have no manual or schematics which makes things interesting lol. That would be great if you’d be up for it too?

That's very interesting. My guess is it's a cap that's gone bad (still!). I'm pretty sure I do have a full service manual for the C5 too - would that help if I send you it (it'll be a digital copy)?

@@MrBetaByte That would be fantastic Thankyou, you were bang on the money with your capacitor theory, we found a tantalum capacitor which was dead short, luckily we had one of the same value knocking about. The machine now powers up and plays! The sound is a bit warbly, the picture jumps about a bit and the rewind is virtually none existent but it’s a step in the right direction!

Yes, certainly replace them with good quality electrolytics but if you do choose to use tants you know they will never go bad again. :-)

Hi and sorry for the delay in reply. Have you tried feeding a video signal through the line in and seeing if you have any EE?

Sorry - I thought I'd replied already but it looks like it didn't commit my reply. Yes, the bead tants are totally fine and will work well. Don't worry about voltage either - as long as they are rated higher than the caps you're changing, you'll be fine.

I tried with kemet film caps for the 0.22 and 0.33uf ones (and quality electrolytics for the 0.47 and 1uf) and that also seems to be working fine so far.

Yes, all should be good and you'll probably never have to worry again about those caps.

I've just changed the mentioned capacitors with the tantalum bead types. The only reason I changed them was because of a slight annoying warble on the sound, after replacing them a short adjustment on the capstan free run speed pot and all is good! Definitely worth changing out those old capacitors !

That's great - as you so, so worth changing those caps. I just do them now regardless as they do make such a difference.