ELY07V552A – mini CRT

Found this mini CRT in a Panasonic NV-M7E that I bought a while ago at a flea market. This was a rewarding salvaging attempt – camera was very easy to open and there are no hidden catches in getting the Electronic View Finder to work.

Camera overview

I proceeded with taking all the screws apart, there are some plastic clips that are keeping the two big sides together, located in the lens housing. A squeeze along the joints and they let go.

There were already good signs – the EVF unit was hooked with an external cable – which meant that it would be easier to hook up the necessary signals (Power / Video IN) to get it to turn on:

Inside the camera

The markings inside the camera body seem to indicate end of Sept 1988 as manufacturing date:

and I recognized the style – more through holes components and more standalone ICs. There were some wires going around plus some capacitors / transistors that seemed out of place but nothing too dramatic:

It was time to start investigating the Electronic View Finder but first I had to take some pics since I also salvaged the connector where the EVF plugs in. It is better to see how the original wires were connected – just in case it may be hard to track down which PINs do what.

EVF Unit

I was impressed with how easy was to get to circuit boards and I figured this camera was meant to be serviced. I thus proceeded to take apart the Electronic View Finder – curious of what lies within and hoping it would work.

There are two screws holding it closed but one is hidden under the metallic rail. To release the rail you have to push down onto the plastic clip below and then the rail can fully slide out – revealing the second screw underneath:

There are also plastic clips clamping everything together – but side pressure will get them to let go.

Few observations: The board is driven by AN2510s IC and there are no signs of any leaky capacitors. I know this doesn’t mean anything, but I was glad there is hope to get it to run without having to swap them. However, everything seemed reachable in case I needed to.

Few measurements later and I was ready to power it up. There is continuity between the case of the Flyback Transformer and one of the pins (the brown wire) which is usually GND. FBTs have other pins that are connected to VCC and few cross-checks later – and I had a possible candidate for VCC input pin. I do not touch the board while it is powered, since high voltages are present.

One trap was the black wire which seems to be connected to camera chassis (I am reusing the EVF plug and this plug had a black wire connected to camera chassis). This doesn’t seem to be connected to GND (or at least, not part of the Video Output).

No surprises, very easy to get started and very impressed by the quality of the image. Sharp, no distortions and image fits the CRT. The display is horizontally flipped since there is a mirror inside the EVF – but here I was photographing directly the CRT:

When doing the photos, I realized something was a bit off with the gray shades, some gray looked white while the white looked a little more gray. I did not try to fix nor play with the controls. As long as the CRT produces images and is bright, I leave it there.

One more thing to mention, voltage needs to be bumped up to slightly above 5V to get the sharpest possible image:

Few more shots of the CRT:

An easy to get into camera and a working EVF unit, ideal candidate for disassembling and see this older technologies up-close.