- AC power connectors - 1 Update
- Vizio, no picture - 5 Updates
- Carvin B2000 bass amp won't power on, need schematic. - 4 Updates
| vjp2.at@at.BioStrategist.dot.dot.com: Oct 02 02:20PM How standard are the appliance side 2-connector connectors for AC? I have a Metsonix SCA radio where the connector that goes into the radio is flakey on the cable side. The connector looks squished oval, two female connectors, looks like it has a polarity key but I don't think the radio has a polarity key. I'm wondering if we have any connectors in our home "lab" which has been around longer than me and I'm also wondering if the wire from dead laptop power supplies might work. -- Vasos Panagiotopoulos, Columbia'81+, Reagan, Mozart, Pindus blog: panix.com/~vjp2/ruminatn.htm - = - web: panix.com/~vjp2/vasos.htm facebook.com/vasjpan2 - linkedin.com/in/vasjpan02 - biostrategist.com ---{Nothing herein constitutes advice. Everything fully disclaimed.}--- |
| Stu jaxon <stankowalski02@gmail.com>: Oct 01 12:13PM -0700 > Good luck with it! Really! And to avoid snarky responses such as this one in the future, please tell us what you have done to-date, try to tell us whether the problem is recent, sudden, developing or any other conditions that may be useful to know, and please also understand that we are some distance away from you and cannot see what you see. So ALL WE HAVE is what you tell us. > Peter Wieck > Melrose Park, PA 8 led strips are out/shorted,.. do i look for shorts in the power supply or led driver board?? this isn't my tv . |
| "ohg...@gmail.com" <ohger1s@gmail.com>: Oct 01 04:56PM -0700 On Thursday, October 1, 2020 at 3:13:29 PM UTC-4, Stu jaxon wrote: > 8 led strips are out/shorted,.. do i look for shorts in the power supply or led driver board?? this isn't my tv . Most late model TVs have LED issues, and it's usually inside the display. That one you have is a real toilet. Does the LED harness plug into CN802 on the main??? |
| legg <legg@nospam.magma.ca>: Oct 01 09:14PM -0400 On Thu, 1 Oct 2020 12:13:24 -0700 (PDT), Stu jaxon >> Peter Wieck >> Melrose Park, PA >8 led strips are out/shorted,.. do i look for shorts in the power supply or led driver board?? this isn't my tv . Had this in a couple of widely varying makes and models. So long as the LED loads are seen to be irregular, the unit probably won't run. If you replace the defective strings with a constant voltage shunt load of the proper value, or replace damaged strings, you can see if there's anything else thats gone wrong. This form of circuit protection is pretty annoying. The screen will be visible, so long as a string still functions. I expect it's a safety issue, with most inexpensive optical screen and dispersion media having been highly flammable, at one time. RL |
| Stu jaxon <stankowalski02@gmail.com>: Oct 01 07:38PM -0700 > On Thursday, October 1, 2020 at 3:13:29 PM UTC-4, Stu jaxon wrote: > > 8 led strips are out/shorted,.. do i look for shorts in the power supply or led driver board?? this isn't my tv . > Most late model TVs have LED issues, and it's usually inside the display. That one you have is a real toilet. Does the LED harness plug into CN802 on the main??? there are two harnesses that plug into the led driver board #715G7159-P01-000-004K cn801, cn802, |
| "ohg...@gmail.com" <ohger1s@gmail.com>: Oct 02 04:39AM -0700 On Thursday, October 1, 2020 at 10:38:08 PM UTC-4, Stu jaxon wrote: > > > 8 led strips are out/shorted,.. do i look for shorts in the power supply or led driver board?? this isn't my tv . > > Most late model TVs have LED issues, and it's usually inside the display. That one you have is a real toilet. Does the LED harness plug into CN802 on the main??? > there are two harnesses that plug into the led driver board #715G7159-P01-000-004K cn801, cn802, CN801 is the harness that goes to the LEDs. If you get no flash whatsoever (however briefly), then you most likely have a bad main board. Even a bad LED strip would allow a short flash of the others before shutdown. The only very rare exception is if this is one of those models that doesn't shut down the LED driver with an open string, and the customer kept watching it as each of the 5 strings died one by one over several months. I've only seen a couple of models that would continue to run with open strings. You really need an LED tester (0-300 volt) that are widely available for less than $50. |
| David Farber <farberbear.unspam@aol.com>: Oct 01 03:21PM -0700 On 9/21/2020 8:55 PM, David Farber wrote: > -- > David Farber > Los Osos, CA Schematic is here: https://cdn.shopify.com/s/files/1/0476/5297/files/30-02050revj.pdf?2645 I finally was able to figure out where all the power supply components were hiding. They were obscured by the heat sinks. The culprits were Q800 and Q802. Their part numbers are STGW30NC60W and they were both shorted across all three terminals. I still have one issue that needs resolving. I performed an in circuit diode test across D809 and D810. They both read 105 ohms (regardless of the polarity of the probes). In essence, connecting either one of those diode's terminal with one probe and then connecting the other to ground yields that same 105 ohm reading. On the other side of that bridge diode circuit, D811 and D812 yield normal front to back in circuit diode readings. Desoldering any of the components is quite a chore because of the double-layered board. I am stumped trying to figure out the troubleshooting path of least resistance here. I haven't ruled out that the 105 ohm reading may just be normal but my gut feeling says it's not. Thanks for your reply. -- David Farber Los Osos, CA |
| legg <legg@nospam.magma.ca>: Oct 01 09:24PM -0400 On Thu, 1 Oct 2020 15:21:36 -0700, David Farber <farberbear.unspam@aol.com> wrote: <snip> >the double-layered board. I am stumped trying to figure out the >troubleshooting path of least resistance here. I haven't ruled out that >the 105 ohm reading may just be normal but my gut feeling says it's not. The anodes of D809 and D810 are DC-shorted through the transformer winding. The 105R reading is likely between LORAIL+ and ground. RL RL |
| legg <legg@nospam.magma.ca>: Oct 01 09:29PM -0400 On Thu, 1 Oct 2020 15:21:36 -0700, David Farber >were hiding. They were obscured by the heat sinks. The culprits were >Q800 and Q802. Their part numbers are STGW30NC60W and they were both >shorted across all three terminals. Check the gate components, if the fets fail. They don't always survive. The primary housekeeper around Q803 should run independently, with big fets out of circuit, so you can check basic control and drive circuits without a lot of risk (taking in mind it's still a primary-connected circuit. RL |
| Phil Allison <pallison49@gmail.com>: Oct 01 11:51PM -0700 David Farber wrote: ------------------ > were hiding. They were obscured by the heat sinks. The culprits were > Q800 and Q802. Their part numbers are STGW30NC60W and they were both > shorted across all three terminals. ** That is bad sign of other problems in the amp. Those are high power IGBTs and they do not blow without a reason. ..... Phil |
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