Identify a part for my VCR psu

[Vauxfan2k]

Hi,

Can anyone help me identify this part and where to get a replacement?

It's for my Philip's matchline VCR. Which had a ticking psu, but after a few mins it powered on for a while and gradually started to lose voltage. Then it went dead with only the loading motor clicking in rhythm to he psu ticking.

I've identified this part, which is obviously fubar'd

Help?

Thanks

Steve

[ekjdm14]

it's a .068uF class X2 capacitor, Wima brand, likely to have smoked in smelly fashion when it failed and maybe caused a blown fuse or tripped breaker?

Replace with another X2 rated cap (of the same value since they're easily available still) as it'll likely be connected directly across the mains. I wouldn't have expected the failure of this to cause a cycling PSU but stranger things have happened (perhaps it's now open and RFI is causing the power supply to freak out, since these tend to be used to suppress mains borne noise.)

Try to avoid any branded WIMA or RIFA, smoke bombs supreme

[cmjones01]

The power supply would still work without that part, because it's just a radio interference suppression capacitor. It's extremely unlikely to be the cause of the fault. I'd be looking at the electrolytic capacitors in the rest of the power supply.

Chris

[Vauxfan2k]

This is the psu.

I've replaced all the 25v caps on the secondary side as that's all I had in spares.

The 400v 47uf capacitor in the primary side I cant replace as I've nothing anywhere near the same value in any of my other machines.

[Vauxfan2k]

The machine was working for a while but eventually it would go into syandby if you tried to perform an operation. Then after powering off from the mains, it didnt come back on.

[ekjdm14]

I can see another smoke bomb in there that should go, the bigger 0.01 top left of the photo.

It might be worth rooting out a suitable replacement for that big electrolytic though as that would strike me as a more likely suspect for a non-starting/cycling PSU (not enough "kick" to get going).

I take it the fault had already occurred when you began work, and not just cropped up since replacing the caps?

[Vauxfan2k]

Yeah it was there already. I have another Philip's machine that ticks for about 5 mins then powers up, it stays working along as the mains isn't interrupted. So guessed this was a similar fault. But this one refuses to start regardless of time lef. I've sent for a replacement 400v 47uf capacitor. Will change that next.

[cmjones01]

That other little electrolytic on the primary side is also a top suspect. It's usually the smoothing capacitor for the supply to the switch-mode controller chip. When it dries up, it can often result in a supply that will only start when warm, or keeps ticking and restarting.

Chris

[ekjdm14]

I missed that beggar! Too busy worrying about WIMA's

[Vauxfan2k]

That small electrolytic is 35v 56uf. Will replace that too

[Refugee]

If that Wyma is a dropper for the start up voltage for your SMPSU chip it may also have done in the zena diode on the same rail as the 56uf cap.

[Maarten]

Originally Posted by ekjdm14

Try to avoid any branded WIMA or RIFA, smoke bombs supreme

Actually, while WIMA manufactures paper caps that are only marginally better than the ones RIFA make which should of course be avoided, WIMA is mostly known for their very well built polypropylene X2 capacitors which will never break again. I'd use those any time since they are toroughly proven.

That said, there will be some dried out electrolytics that need to be replaced.

Is this a VR833 or VR948 by any chance? Philips videq themselves wouldn't have used paper capacitors anymore since they noticed them blowing up prematurely in their V2000 recorders, but i3R Neurenberg might have since those early models from that joint venture were almost fully based on Grundig designs.

EDIT: it indeed looks like it, also the power supply has both a Philips and a Grundig number on the PCB so that makes sense.

[Vauxfan2k]

Maarten it's a VR838 Matchline.

I've ordered all the caps, so will fit and try when they have all arrived.

Hopefully the diode will be ok. If not does anyone know the rating?

Thanks

[Clydeuk]

In my experience, those large 400v caps on the primary very rarely fail. If you can measure >320 VDC across it then it's probably perfectly good.