Capacitors for a JVC DR-MH30SEK

[ETON993]

I have acquired an old JVC DR-MH30SEK dvd hard drive recorder (PAL UK Model), not working & I am trying to find out what the capacitors should be on the power board!

The serial number of the machine is 090B0096 (Don't know if this helps!)

The circuit board is marked as REG PWB ASS'Y LPA10237- 24D (not sure about the 24D as this is hand written, don't know if it is relevant or not)

The capacitors I am trying to identifiy are: C5103, C5201, C5202, C5203, C5204, C5206, C5207, C5208, C5209 & C5210

Can anybody tell me what capacitors should be in these locations?

Thanks for any help you can give.

[tomlee59]

Do these capacitors have any markings at all? Are these surface-mount devices? Radial-lead?

It is unusual for caps to have no markings (unless they are tiny SMDs).

Perhaps you could post a pic or two?

In the absence of a schematic, it's helpful to note that power supplies are generally simple things, topologically. Caps on the output tend to be high-value, low voltage electrolytics, and fail somewhat frequently in switch-mode supplies. Those on the input side, if line-operated, tend to be medium-value, high-voltage electrolytics of large physical size, and fail less frequently. There will also be a small handful of non-electrolytic devices, generally used for loop stabilization. These essentially never fail, so one's troubleshooting focus should be on the electrolytics.

[lordsmurf]

Your are very wise to try and repair this great unit.

Lazy schmucks keep trashing these hard-to-find machines, replacing them with crap (Panasonic, etc). I wish I had a dumb neighbor, I'd love to dumpster-dive one of these!

[ETON993]

Thanks for your replies

The problem is that I believe that someone has already had a go at repairing this machine & has probably replaced some of the capacitors incorrectly. That is why I am trying to identify what should be there!

The capacitors are all surface mount radials, and the existing capacitors are all marked up with sizes.

Any ideas?

[tomlee59]

Thanks for your replies

The problem is that I believe that someone has already had a go at repairing this machine & has probably replaced some of the capacitors incorrectly. That is why I am trying to identify what should be there!

The capacitors are all surface mount radials, and the existing capacitors are all marked up with sizes.

Any ideas?

A surface-mount device has no wire leads. It's just a small rectangular block with conductive regions on each end. The rectangle then solders to pads on the circuit board surface. No holes need to be drilled for leads to go through, because there are no leads. Saves space, and allows for rapid mass assembly.

A radial-lead electrolytic capacitor is generally a cylindrical thing with two wires sticking out of the bottom. An axial lead electrolytic capacitor is also generally a cylindrical thing, but with a wire coming out of each end. [The focus on electrolytics here is because of their high failure rate.]


The physical shape and size of the capacitors is sometimes a helpful clue as to their function, in the absence of a schematic. If you could post a pic, that might be helpful until you get lucky and someone sends you a service manual.

And if by "marked up with sizes" you mean that their values and voltage ratings are printed on them, then that's very good news.

If they are electrolytics, then take a close look at them. If there's bulging on the top or bottom (particularly the former), it's dead.

[johns0]

[quote="tomlee59"]

There's no such thing as a "surface mount radial" capacitor.

Sure there is.

[tomlee59]

<<slaps forehead repeatedly>>

I've edited my previous post to correct it.

<<more slaps. Goes comatose>>