- sata port failure on HP motherboard - 2 Updates
- Zenith safety cap ID (22-7672-05) - 7 Updates
| tabbypurr@gmail.com: Aug 31 04:46AM -0700 On Thursday, 30 August 2018 03:27:44 UTC+1, root wrote: > > https://www.amazon.com/Vantec-6-Port-SATA-Host-Card/dp/B002PX9BX2 > I made that suggestion to the owner of the MB. She declined because > she thought the MB was no longer reliable. A card is good, but a grossly overheating chip does still in place not make for a reliable board. But it's a very cheap option that will likely work. NT |
| John-Del <ohger1s@gmail.com>: Aug 31 09:15AM -0700 > A card is good, but a grossly overheating chip does still in place not make for a reliable board. But it's a very cheap option that will likely work. > NT We don't know that it's overheating. It could be running at the right temp but still failing thermally. |
| jurb6006@gmail.com: Aug 30 05:58PM -0700 >"he may not have waited 20 years to scrap that antique. " If I had one of those I would restore it or at least make it work if the CRT was good. |
| jurb6006@gmail.com: Aug 30 06:01PM -0700 >"It's puzzling enough why people reply to old posts," Seems most of them are on Google. They're probably doing a search and when they get hits they neglect to notice the date. |
| John-Del <ohger1s@gmail.com>: Aug 30 07:01PM -0700 > >"he may not have waited 20 years to scrap that antique. " > If I had one of those I would restore it or at least make it work if the CRT was good. I have a customer with a late version of the Zenith Vertical Chassis. The old bat insisted I fix it for her again a few months ago (put in a tripler about two years ago). It was shrinking left and right and blooming, and I remember fixing a bunch of these for the same problem. When I pulled my schematic I remembered that carbon resistor that overheats and goes up in value behind the 9-90 module. Looked pretty good with the sweep back to normal; strong tube. If she ever calls me to dump it, I'm putting it my truck and driving it over to your house. |
| jurb6006@gmail.com: Aug 30 09:39PM -0700 That line started with the EC line. The best of them IMO was the GC line, ideally a 25GC45 or 50. They continued the type of chassis but started using those hybrid resistors in the later ones. Another goodie from back then was the Magnavox T995 chassis, I would take one but I want the older version with the volume under the tuners that actually had good sound. I had a GC Zenith with good sound as well, both of them later went with speaker speakers, and the Magnavox ones switched to a volume control with a shitty taper, the older ones were nice and smooth. Those were part of my "good" lie of sets when I was in business. They got 30 days on everything, 90 on parts and a year on the CRT. there was NEVER a TV in my main showroom with a rejuvinated CRT. Then we had the discount sets. If I zapped the tune that's where it went, and I told people they were, but all was not lost because ?I had one of the best rejuviators - a B & K 467. It had a very nice touch and didn't destroy the cathode. They gave you a stack of ONE YEAR warranty cards to give the customers with a set that had a zapped CRT. One advantage we had was a good source for rebuilt CRTs. I forgot the name of the place but a old German guy ran it, did all the work himself. Gave a 3 year warranty. I think he was called Willie. |
| tabbypurr@gmail.com: Aug 31 04:43AM -0700 > Another goodie from back then was the Magnavox T995 chassis, I would take one but I want the older version with the volume under the tuners that actually had good sound. I had a GC Zenith with good sound as well, both of them later went with speaker speakers, and the Magnavox ones switched to a volume control with a shitty taper, the older ones were nice and smooth. > Those were part of my "good" lie of sets when I was in business. They got 30 days on everything, 90 on parts and a year on the CRT. there was NEVER a TV in my main showroom with a rejuvinated CRT. Then we had the discount sets. If I zapped the tune that's where it went, and I told people they were, but all was not lost because ?I had one of the best rejuviators - a B & K 467. It had a very nice touch and didn't destroy the cathode. They gave you a stack of ONE YEAR warranty cards to give the customers with a set that had a zapped CRT. > One advantage we had was a good source for rebuilt CRTs. I forgot the name of the place but a old German guy ran it, did all the work himself. Gave a 3 year warranty. I think he was called Willie. Zapping CRTs ruins them. As emission falls again, as it does, severe smearing occurs. A much better fix is to boost the heater voltage: this lasts. I wasn't a big fan of 10% boost, 33% does the job on most sets. An extra turn on the LOPTF does that easily & cheaply on most sets. I did try 66% voltage boost on a couple of really bad ones just for experiment's sake, and surprisingly it worked & kept working. One (Sony Trinitron) was so bad that nothing was visible at all on screen, even in a dark room. What kind of strange person kept using it until it reached that point who knows. Anyway the result was plenty of output on all channels, but colour tracking was lousy. That kept working for years until I tired of it. NT |
| jurb6006@gmail.com: Aug 31 07:07AM -0700 I always tried boosting the filament first. Zapping was the last resort. Even boosting the filament kept it out the prime stock category. |
| John-Del <ohger1s@gmail.com>: Aug 31 08:09AM -0700 > Zapping CRTs ruins them. As emission falls again, as it does, severe smearing occurs. A much better fix is to boost the heater voltage: this lasts. I wasn't a big fan of 10% boost, 33% does the job on most sets. An extra turn on the LOPTF does that easily & cheaply on most sets. > I did try 66% voltage boost on a couple of really bad ones just for experiment's sake, and surprisingly it worked & kept working. One (Sony Trinitron) was so bad that nothing was visible at all on screen, even in a dark room. What kind of strange person kept using it until it reached that point who knows. Anyway the result was plenty of output on all channels, but colour tracking was lousy. That kept working for years until I tired of it. > NT In my experience, boosting filament delivered the shortest amount of service life of any method. Back in 1981, RCA had a short run of bad HV transformers (quickly resolved). The trans was mostly conventional but had a single brown wire for CRT filament from one of the exterior terminals that went to the CRT board. As originally installed, the wire was routed between the metal frame of the trans and the chassis (metal back then). If the trans was replaced and the brown wire was routed by the core and not between the frame and the chassis, the filament would pick up a few hundred milivolts by induction and add it to the normal 6.3. Several months after the trans was installed, the CRT would be shot. Fortunately, this happened in warranty. RCA quickly added a bulletin and a service note in the replacement trans that described how to properly route the filament wire. Zenith in the 90s had a bunch of tubes suffer heater to cathode shorts. Most guys would thread two or three turns of bell wire around the HV trans core and feed the filaments directly (after cutting the grounded filament circuit). This would allow a full floating filament supply that wouldn't pull the cathode low even if the fil should short to the cathode. Problem was, guys would just wire so the filament looked the right color temperature but if the final voltage was much above 6.3, the tube would tire in a few months. The solution was to use a TRMs meter (15K cycle AC from the fly) and adjust with winding count and/or a resistor to ensure the filament stayed at or even a bit smidge below 6.3TRMS AC. I did those and got many years out of those repairs. Going back farther, we used to install hang on filament boosters in TVs with weak tubes to allow customers time to either save for a new TV or a CRT swap. Typical life of a boosted tube was two to six months. I bought a new B&K 467 (still have it and two others from closed shops) and the life of the CRTs after boosting was 6 months to two years. The Sencore was supposed to be better but I never had one of those. In any case, we never sold a boosted tube of any type. |
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