Help please to fix my old FISH8840 ![Scared :scared:](https://www.eevblog.com/forum/Smileys/default/scared.gif.pagespeed.ce.oZptHNcbsD.gif)
Hi everyone, and thanks very much for all your work on these clone testers!
I would like to repair my original FISH8840 "Big Screen", to repay it for many years of faithful service. It's had the "power fix", upgraded LDO, matched resistors, etc but now the screen is stuffed.
It's been in storage for years, however I think that the front polarizer peeled off - anyway, now it has a very strange circular distortion (see attached pics). I tried overlaying a few polarizing sheets but they didn't improve it, so I thought maybe it used a circular polarizer or something?
The screen is 63 x 51mm, with an 18-conductor ribbon. I've attached a photo of the rear of the PCB, and you can see the 6 pin header going down to the main PCB. The SID, SCLK, RS and REST pins go to the LCD, the VCC goes through an LDO, and there's a heap of bypass caps on the other ribbon connections.
I read that it used a ST7565 controller (??), however I have not un-glued the panel to check and there is no markings on the ribbon cable. I tried searching but can't seem to find a matching replacement, nor even a screen with similar ribbon connection.
Do you have any idea what might be wrong with it, and is it repairable? If not, how could I find a replacement screen, even it it's a smaller footprint?
Obviously it'd be easier just to replace the whole gadget, but I thought I'd give you guys a shout out before I retired it permanently. Do you have any ideas or assistance for me?
Cheers, John
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