- Transistors - 2 Updates
- Vizio no pic - 2 Updates
- Anybody got a Wells Gardner 9K7704 yoke? - 2 Updates
| tabbypurr@gmail.com: Jul 15 10:25PM -0700 > if anyone can help me out or point me in the right direction that would be greatly appreciated. > Regards > Richard If you can't find equivalents, work out what specs are needed from the circuit diag & get something that'll do that. People often get too hung up on equivalents imho. NT |
| francesco.messineo@gmail.com: Jul 16 07:24AM -0700 > P4M > 25 > if anyone can help me out or point me in the right direction that would be greatly appreciated. Hi, you might want to post a question on vcfed's forum: http://www.vcfed.org/forum/forumdisplay.php?26-Unix-Xenix-Linux-Workstations Someone there could have a (even partial) schematic of that PSU and help you getting the right replacements. The closest SUN workstation that I have at home is a SS10 so I don't think there're chances that it uses the same PSU as the Classic. By the way, what's wrong with the original parts? |
| Stu jaxon <stankowalski02@gmail.com>: Jul 15 06:07PM -0700 On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote: > With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good. > So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time. > I can check Monday to see if I have a verified good TCON in the shop. if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can. |
| John-Del <ohger1s@gmail.com>: Jul 16 06:52AM -0700 On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote: > > So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time. > > I can check Monday to see if I have a verified good TCON in the shop. > if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can. FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are. I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON. If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix. If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them. |
| John-Del <ohger1s@gmail.com>: Jul 15 12:22PM -0700 Table top arcade game from Merit. Horizontal windings burned under the convergence magnet tape. I separated the windings and repaired the break, but it's still not right. The monitor is a Wells Gardner 9K7704 with a DSG-0992CL deflection yoke. |
| John Robertson <spam@flippers.com>: Jul 15 01:49PM -0700 On 2019/07/15 12:22 p.m., John-Del wrote: > Table top arcade game from Merit. > Horizontal windings burned under the convergence magnet tape. I separated the windings and repaired the break, but it's still not right. > The monitor is a Wells Gardner 9K7704 with a DSG-0992CL deflection yoke. We may have that yoke, I'll have to remember to ask Alex tomorrow (service manager). You can send me a note as a reminder! John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
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