Main Restorations Software Audio/Jukebox/MP3 Everything Else Buy/Sell/Trade
Project Announcements Monitor/Video GroovyMAME Merit/JVL Touchscreen Meet Up Retail Vendors
Driving & Racing Woodworking Software Support Forums Consoles Project Arcade Reviews
Automated Projects Artwork Frontend Support Forums Pinball Forum Discussion Old Boards
Raspberry Pi & Dev Board controls.dat Linux Miscellaneous Arcade Wiki Discussion Old Archives
Lightguns Arcade1Up Try the site in https mode Site News

Unread posts | New Replies | Recent posts | Rules | Chatroom | Wiki | File Repository | RSS | Submit news

  

Author Topic: D9410 side squished  (Read 1207 times)

0 Members and 1 Guest are viewing this topic.

lilshawn

  • Trade Count: (+3)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 7494
  • Last login:Today at 06:54:37 pm
  • I break stuff...then fix it...sometimes
D9410 side squished
« on: June 06, 2024, 02:27:27 pm »
D9410, running 640x480 60hz.

working except for horizontal linearity at the edges.. it's squashing and expanding down quite a bit when the horizontal position is changed.

left side looks okay but also seems to move/expands when horizontal position /size is modified. thinking it might be something in the horizontal linearity circuit but not real sure... short clip of what it's doing...

https://photos.app.goo.gl/bBRDQE2LCdbi3U2CA

lilshawn

  • Trade Count: (+3)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 7494
  • Last login:Today at 06:54:37 pm
  • I break stuff...then fix it...sometimes
Re: D9410 side squished
« Reply #1 on: June 13, 2024, 01:32:39 pm »
not sure what the deal is with it, it seems to operate normally at 800x600.

i thought maybe it was an S correction cap in the resolution switch circuit so i swapped out the 4 (c244 to c247) since i' dont know exactly which is enabled for that resolution...

but unfortunately it still seemed to do it. i did swap out all the switching fets and transistors coming from CS0/1/2/3 due to the monitors original failure. so i know it's not that. maybe it's a fried CS line coming from the CPU, but i don't know what the logic is for the different resolutions to dig into this more.

in any case, it's working good enough.

original failure was the typical yoke horizontal shorting out and dumping 195 volts into....everywhere. removed yoke and repaired/sealed the windings and re-sealed the neck insulation. replaced 48 components, diodes, resistors, caps, fets, transistors....  and managed to get it going again.

i feel this issue stems from the tube neck insulation drying out, cracking and flaking off. this insulation also seems to corrode and attack the lacquer insulation on the yoke windings (similar to how the yellow glue on the boards turns brown... then black and becomes corrosive and conductive.).... eventually a perfect storm of corrosion, bad insulation and static buildup.... eventually having a discharge into the h winding, the main switching FET shorts out, then all hell breaks loose. the chassis gets a shotgun blast of 195 volts to dozens components frying/shorting/and blowing open circuit stuff,  until nothing's left in the 195v path..and anything unfortunate enough to short circuit to a lower voltage rail. loads of fun.

basically everything in attached...  :dizzy: