- CRT long warmup time? - 3 Updates
- Sony Bravia xbr-55x850c six red flashes but then sometimes re-starts? - 1 Update
| john <john_crane_59@yahoo.com>: Jun 18 04:23PM -0700 As it turns out the caps are excellent and the voltages rock steady. Almost unbelievable for a 50 year old device (an HP-9100B). The 24V supply was for some reason at 31V. I tweaked it down with an adjustment resistor on the cards, and the CRT came up in 12 seconds. Manual says within 20 secs - so it seems fine. Thanks! -John |
| Jeff Layman <Jeff@invalid.invalid>: Jun 19 10:11AM +0100 On 19/06/2023 00:23, john wrote: > As it turns out the caps are excellent and the voltages rock steady. Almost unbelievable for a 50 year old device (an HP-9100B). > The 24V supply was for some reason at 31V. I tweaked it down with an adjustment resistor on the cards, and the CRT came up in 12 seconds. Manual says within 20 secs - so it seems fine. Thanks! -John I spent some time with its successor - the 9810A (https://www.oldcalculatormuseum.com/hp9810a.html) in early 1972. As that article notes, it was a choice between the HP and a Wang. The HP was a great machine, and quite easy to program although I had to get used to RPN. It was being used in a lab, and my boss used to program it as well. I well remember one day when he'd spent hours inputting a big program (IIRC around 1600 steps) when his office phone rang. He left the machine to answer it, and a few seconds later the student who was with us on a job experience program came in to use the machine. He didn't check if it was in use, and just turned it off and on again to do what he wanted. I never knew my boss had such a vocabulary of swear words, and the student hid somewhere until the boss had calmed down! Mind you, if he'd only paid attention and followed the instructions to now and again record on the magnetic cards what he'd done, he'd not have lost hours of work. -- Jeff |
| "ohg...@gmail.com" <ohger1s@gmail.com>: Jun 19 06:49AM -0700 On Thursday, June 15, 2023 at 1:02:30 PM UTC-4, john wrote: > Any ideas as to what would cause a CRT to take 10mins to warmup before it displays anything? Maybe old capacitors? This thing is a 55 year old calculator. > -John Does the display suddenly appear nice and bright after 10 minutes of darkness or does it slowly fade to life? Either can be circuit component issues but a slowly appearing image sounds like a very tired CRT. If it's the latter and the machine hasn't been used in many years, then just running it several hours a day will generally perk up a tired CRT. If the image appears suddenly and looks good, then it's most likely a circuit issue. A service manual would be handy in checking to see if the heater voltage and HV appear immediately (the two most likely issues). If all the voltages are good, then you need to scope the grid of the CRT backwards and see where you are losing you video. |
| "ohg...@gmail.com" <ohger1s@gmail.com>: Jun 19 06:43AM -0700 On Thursday, June 15, 2023 at 3:41:29 PM UTC-4, Amanda Ripanykhazov wrote: > Someone gave me this tv and i pugged it in to test. Suddenly after four days of (the screen) working properly, I connected to cable and the TV cuts out, gives the 6 blinks repeatedly. > But then it turns on again as if everything is normal? And the 6 blinks dont happen (as described on various videos) after the partial or whole-screen shutdown which is the problem when the backlight LED is dying. > Is this 6 red flashes the generalised error message when the TV is in its death throes? This model generally doesn't have any problems with its backlighting (despite what the error code may say), but the main boards are junk. The Sony Android TVs of this era usually have the main board start getting glitchy, then wonky, then they end up dead. There are two large BGAs on these boards and they both need to be reballed (a reflow may buy you time but it's not permanent). A used or "recertified" board will also buy you time, but working Sony Android boards are expensive and not worth the short time they have left. When I take any of these on trade they get recycled without exception. |
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