back to LCD vertical line repair attempt

3 LCD maintenance:


My LCD had a few rows and MANY columns out, which was making reading the display difficult.

After removing the remaining two smaller screws, the LCD assembly can be slid up and lifted away from the
board, exposing its connection to the board along with the cable, which integrates the display driver IC.

Although the solder to the board is pretty nasty, it's a digital connection, so any problems here would
likely result in complete failure of the display, and not affect rows or columns.

The other end of the cable is then bonded to the plastic jumper to the display. That could be a problem, but
the connections are in between the cables and not easy to examine or work on.

Flipping it over exposes where the flex cable is glued to the LCD glass itself. Some displays use a "zebra bar"
to connect the driver IC to the display, but Yaesu chose to go with semi-conductive glue, which has proven to be
an unreliable manufacturing method wherever its used.

The lines going to the display are incredibly small and close, more so thana I've ever seen in a display, so
there's NO hope of re-gluing that connection. I'd never get the wires aligned on the glass right.

I didn't get pics, but what I did was set my rework to 150F at slow air and ran over the black area where the
ribbon meets the glass several times to warm it up. I then rubbed the black area with the q-tip using moderate
force, to re-set the glue. I did this with the display plugged in and powered, and could immediately see rows
and columns going in and out as I rubbed, but after a few passes, the glue re-set and the display became
completely stable. I got back almost all the columns, and a few of the rows, but at that point no amount of
rubbing or contact caused any change in the display. (it was "stabilized") I accepted the improvements and
reassembled it.

I was disappointed to see that by the time I got things reassembled, most of the columns I had "fixed" had
gone away again. The mix of the semi-conductive glue they used on the line just wasn't up to the task and
would have to be re-applied to fix this problem, which isn't something even most experienced techs could
manage. So I guess at this point all I can do is use an external CAT display or find a replacement somewhere.

11 LCD rows and columns are out	19 display lifted	20 display board connection detail	21 underside of display cable	22 underside of display cable	23 top side where calbe meets glass
24 heat and rub here	25 after reassembly

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