Sony Watchman FD-40A Wavy Screen - Videokarma.org TV - Video

aapljack · #1 09-24-2022, 12:43 AM

I picked up a Watchman FD-40A from eBay. It was described as working. As it does work, the screen is wavy. Is there a fix for this? Maybe some caps that went bad?

Also, what kind of cord can input video in the A/V input on the side. I tried an 1/8" plug that goes to RCA connectors. Nothing. Also tried just the RCA video connector plugged in. When I touched the connector to the plug I got something, but when fully plugged in, nothing came though.

zeno · #2 09-24-2022, 02:54 PM

Dont know about the wavy lines. We wouldnt toch one. Just sent them
to Sony even though we were factory service center.

Are you using a stereo jack ? must be what they do. If you can find the manual on line that will list the cable part ##

73 Zeno

LFOD !

Electronic M · #3 09-24-2022, 07:03 PM

Does it do the wavy thing on batteries too? If not it's possible your power brick may have a bad cap or the filters in the set are bad.

I've never had the video cable for one of those but I remember it being a Non-standard RCA jack where the center pin was a 1/8" mono headphone plug. You need at least 3 conductors/terminals for the Video and Mono sound this uses so that eccentric method is how Sony did it on a single connector. Don't ask me where to find one, I've only seen pictures.

aapljack · #4 09-24-2022, 08:43 PM

Thanks!

I have not tried it with batteries. I’ll give that a shot.

jhalphen · #5 09-25-2022, 06:05 AM

Hi to all,
Hi aapljack,

Schematic of the Sony FD-40A Watchman, PCB component board & zoom on A/V input socket.
Resolution is ho-hum, Sorry! i don't have anything else in my files.

Best Regards
jhalphen
Paris/France

zeno · #6 09-25-2022, 06:58 PM

That shows the way they do it. A 3 conductor plug. Probably a 3.5 mm
stereo jack. One for mono audio the other for video. Third common ground.
Keep in mind there are switches in the jack. Also just like wall wart
jacks they get cold joints OFTEN especially when used a lot.

Zeno

LFOD !

jr_tech · #7 09-26-2022, 12:51 PM

Quote:

Originally Posted by zeno

That shows the way they do it. A 3 conductor plug. Probably a 3.5 mm
stereo jack. One for mono audio the other for video. Third common ground.
Keep in mind there are switches in the jack.

It must be a hybrid plug, because the outer conductor on the set is clearly rca style. Imagine a 3.5 mm headphone jack with rca style ground.

I have never seen one.

jr

ARC Tech-109 · #8 09-30-2022, 06:25 AM

Anyone know where to find a good clean schematic for the FD-40 Watchman? Mine has a low horizontal drive like it's missing the boost and not compensating the width over the vertical scan cycle. Thanks in advance

zeno · #9 09-30-2022, 02:51 PM

As far as PDF's go this aint so bad. Only alternative is an
OEM paper copy.

Zeno

jhalphen · #10 10-01-2022, 04:05 AM

Hi to all,

Hi ARC Tech-109,

A quick search yielded the full Sony FD-40A service manual as a free pdf file.
Download it here, file is 6.4Mb :

https://ia904504.us.archive.org/28/i...FD40A_SONY.pdf

Hope this helps you repair your WatchMan, please keep us informed of progress,

Best Regards
jhalphen
Paris/France

ARC Tech-109 · #11 10-02-2022, 01:54 PM

Oh wow thanks for the link!

You are the man!

Tube TV · #12 12-24-2022, 09:18 PM

I have seen this before, not with a watchman, but IIRC it was a Syphonic Minni TV, and it was a filter cap that was weak. Are you using a original Sony adaptor?

Some adaptors have very little filtering and this could be the problem. If the ripple goes away on battery power you can be certain it's a filtering issue.

There is one cap that might be weak inside the TV and I marked it.

Another thing you could try is a capacitor across the power out of the adaptor.
1000 to 2200 UF 16 volt and see if the ripple goes away.