My Sony SLV-SE70 VHS died

Edward Onslow · 24-03-2008, 10:37 AM

I just bought a Sony HXD870 hard disk recorder, but I have a few programs on VHS that I'd like to transfer to DVD.
In the course of fiddling around to set up the copies, it appears that my Sony SLV-SE70 VHS has packed up. The fault appears to be the main PSU, which I could easily replace if I had a spare. Trouble is, with the general demise of VHS, it's very difficult to find a source of (reasonably priced) spares, so I was wondering if anyone could suggest a source of parts. The main power supply is made by Mitsumi, so that's probably the bit I need. I'm an experienced electronics engineer, so replacing the broken unit holds no problems for me.

steverobertsbbc · 24-03-2008, 11:07 AM

Hi Edward,

It'll be a dry electrolytic in the PSU starter circuit, it's a standard fault on these machines. However, you might be able to start it using a trick I often use at work to temporarily get gear back up and working before it's available to be properly fixed... Heat the PSU up with a hairdrier and then apply the power. If you're lucky, the heat will have caused the dodgy C to regain enough capacitance to start the PSU up. Then leave it powered up!

Steve

Edward Onslow · 25-03-2008, 3:19 PM

Hi Steve,

Thanks for the tip. However, I can find no dud electrolytics in the PSU. I assume you are talking about components that are inside the screening box? My module circuit board is numbered SRV878EK. I've checked all the caps and also the diodes but can find nothing wrong.
Could it be something on the main circuit board, on the output side?
Everything on the input side, caps & filter inductors seem OK. When I power up I'm getting 335 Volts DC across the + & - pins feeding the power supply module.
Since this is fed with DC, I assume it's some kind of inverter which is failing to start oscillating.

steverobertsbbc · 26-03-2008, 2:03 PM

Yes, inside the metal PSU can. Have you checked the C's with a capacitance meter out of circuit or with a low series impedance meter in circuit? It's usually a small C in the kickstarter circuit that's at fault. Also, PSU designers have a terrible habit of putting electrolytics next to hot resistors or heatsinks, so look for those.

Did you try my suggestion of heating the PSU up with a hairdrier?

Also, I just did a quick google and found a couple of places that listed: SLVSE70 DEAD C153(47UF50V),C154(1UF63V). These seem to be C's in the PSU and the same replacement turns up for various other Sony VCRs. Sounds like a good place to start...

Steve

Edward Onslow · 27-03-2008, 10:25 AM

Thanks very much for taking the time to reply to this.

I've pulled the caps and measured them out of circuit, with a capacitance meter, but I'll admit I only looked at the larger ones. Everything I've checked appears to be within tolerance. Nothing appears to be burnt or obviously overheated, and it's not blown any fuses. I'll see if I can locate the C's you've mentioned.
I'd really like to fix it, since I've got a few things I want to transfer to DVD, and this is the machine they were recorded on.
Is it possible to get hold of circuit schematics for these?

steverobertsbbc · 27-03-2008, 10:49 AM

I can almost guarantee that it's the 1uF C154 which is causing you the problem. It's part of the kick-starter for the oscillator. Change this (and also C153 as you're at it) and I think it will work.

Steve

Edward Onslow · 31-03-2008, 2:22 PM

Hello again.

Not had any time to look at this until yesterday.

"I can almost guarantee that it's the 1uF C154 which is causing you the problem."

That's one that I hadn't tested, so I swapped that and C153 while I was there and ... It Works!

Thanks very much for the info.
I'd buy you a drink if I could.

Cheers.

steverobertsbbc · 31-03-2008, 5:23 PM

Glad it worked Edward! I'll pretend the next beer was bought by you.

Steve

15-11-2008, 8:25 PM

And thanks from me

Same problem, same solution, next model up (SLV-SE80).

abmck · 09-05-2009, 1:09 PM

Sorry for dragging up an old post, but...

Hi Steve
My Sony SLV SE80 "died" with a new cassette stuck inside.
I did a Google search and this was the only helpful post I read. The power was still coming in as far as the little glass fuse but apart from that --nothing.
With nothing to loose I got the hair drier out and "warmed" the PSU, actually, "roasted" would be a better word...

IT WORKED !!!

Just wanted to say "Thanks" for your help, and Sorry for doubting..

AB

johnperry · 14-05-2009, 6:19 PM

Many thanks for this post. Two caps and I have a working VCR again. Brilliant!

abmck · 17-05-2009, 2:49 PM

Once I'd got the tape out of the machine with the hair drier I put it in the garage to dump the next time I'm going to the skip site.

Is it worth fixing? Is it difficult to replace the parts in the PSU? --I've done a little bit of soldering occasionally.

Any thoughts/advice welcome.

johnperry · 17-05-2009, 4:06 PM

I am by no means God's gift to soldering - agricultural at best! The biggest challenge for me was accessing the board with the two capacitors on it. This involves removal a housing that is itself soldered to the PSU board and a tricky bit of desoldering of the circuit board that holds the capacitors. You seem to need to do this to access the underside of the board. With the components all being refreshingly 'old school', nothing was too difficult to access. For me it was all well worth it.

abmck · 17-05-2009, 8:41 PM

Thanks for that, johnperry.
The shiny thing (technical term) surrounding the PSU does look a bit tricky to get off.
I had a look at Maplins site to try and find the two bits mentioned but couldn't find either.I'd probably fit the wrong thing and burn the house down :-(
The skip is beginning to look like the better (and safer) option.

Thanks anyway!

satchcit · 12-08-2009, 11:56 AM

HI. HAVE HAD THE POWER SUPPLY OUT. AND REPLACED ALL THE USUAL CAPS, BUT TO NO AVAIL. AND NOW I HAVE CHANGED ALL THE CAPS ON THAT BOARD AND IN P S U, IS STILL DEAD. CAN YOU PLEASE HELP, ALAN

johnperry · 16-08-2009, 8:14 AM

Can't really help I am afraid. Sounds a bit terminal though. Stating the really obvious, but there is a fuse _inside_ mine that has blown once in the past...

John Perry

MCRoosen · 05-10-2009, 8:59 PM

Thanks for posting this solution. Worked for me, too.

Bobhmax · 29-12-2010, 9:42 PM

Hello guys,

Thanks a lot for this!! I manage to repair my friend's vcr!
Althought I didn't have the right capacitors, I swapped the 1 µF for a 2,2µF and the 47µF for a 100µF , and it works !!! Maybe it takes a little more time to wake up... but who cares ?
Thanks again, and if I can be for any help...

Bob

15-11-2008, 8:25 PM	#9
snowmole Guest Posts: n/a	Re: My Sony SLV-SE70 VHS died And thanks from me Same problem, same solution, next model up (SLV-SE80).
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29-12-2010, 9:42 PM	#18
Bobhmax New Member Join Date: Dec 2010 Thanks: Gave 0, Got 0 Posts: 2	Hello guys, Thanks a lot for this!! I manage to repair my friend's vcr! Althought I didn't have the right capacitors, I swapped the 1 µF for a 2,2µF and the 47µF for a 100µF , and it works !!! Maybe it takes a little more time to wake up... but who cares ? Thanks again, and if I can be for any help... Bob
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