Fixed a 10yo HP inkjet with a bulging cap on the digital computer power rails (1 to 5V). Unstable voltages causing these inkjets to not boot properly or crash quickly. Seems like more and more of these are showing up nearing the 10 year mark. Board design seem to look similar for many of these printers.

[url]https://h30434.www3.hp.com/t5/Printing-Errors-or-Lights-Stuck-Print-Jobs/OfficeJet-5740-boot-crash-fixed-by-replacing-bulging/m-p/8955317/highlight/true#M997922[/url]https://Fixed a 10yo HP inkjet with ...ltages causing

This post ( [URL="https://forums.macrumors.com/threads/the-dreaded-touchbar-flicker.2278391/post-33560188"]link[/URL] ) tried the small cable and determined it was good. Failure was the long touch bar itself which requires difficult disassemblyThis post ( [URL="https://forums.macrumors.com/threads/the-dreaded-touchbar-flicker.2278391/post-33560188"]link[/URL] ) tried the small cable and determined it was good. Failure was the long touch bar itself which requires difficult disassemblyThis post ( [URL="https://forums.macrumors.com/threads/the-dreaded-touchbar-flicker.2278391/post-33560188"]link[/URL]...

You are correct, proper exit process works fine but of course exit youtube (or any other app) completely. This is likely the proper way with Vizio SmartCast but is less convenient. Slower and can't resume the app

Anyway, very natural and easy to want to hit the vizio button while running apps So vizio probably should improve their menu + app resolution change handling. Usually proper app<->app and app<->desktop context switching is quite difficult for less computer operating system developers (how to handle resolution change is one key design complexity). More capable...

Bug looks like hardware so thought I posted it here. Exact same behavior on 2 different model 4K Vizio TVs running their SmartCast smarttv software. After launching youtube app, press vizio button on remote to return to the smarttv menu, once in awhile, a column of bad pixels will show for few seconds on the left hand side.

[URL=filedata/fetch?id=3508848&d=1731799015][ATTACH=JSON]{"alt":"Click image for larger version Name:\tIMG_3511.jpg Views:\t0 Size:\t2.13 MB ID:\t3508848","data-align":"none","data-attachmentid":"3508848","data-size":"medium"}[/ATTACH][/URL]...

UPDATE 2

Replacement main has 2 problems[LIST][*]WIFI HW would be lost on ECO MODE power off and on. Need to unplug/plug power to recovery[*]All streaming/smart apps crash and reboot randomly[/LIST]Back to using original board fixed enough to work perfect everywhere except no WIFI.

These mains must suffer high thermal failure and WIFI too since its soldered onto main and few centimeters above SOC heatsink diagonally with SOC running ~90C when TV on.

• UPDATE 2
  
  Replacement main has 2 problems[LIST]
• WIFI HW would be lost on ECO MODE power off and on. Need to

UPDATE

Replacement main came in. Installed and wifi works (this TV has no BT) and Power off Eco Mode works as well.

Hot air heated the wifi module ( 2-3x ) on the old main with no WIFI HW detected and Power off Eco Mode not working (TV just restart after turning off). WIFI HW is now recognized (see pic) but can't find any SSID. Power off Eco Mode now works. I guess Power off Eco Mode not working was due to the missing WIFI HW somehow and got fixed once WIFI HW showed up. WIFI not finding SSD probably just shows failed WIFI module.

Anyway, this TV is fixed...

Before you give up, I see signage use for 10 years which likely mean a lot of hours on the backlight. Do you have a LED tester? And besides testing on the contacts on the LED strips, try testing it from the other side of the connector on the vertical strip and maybe all the way back to the 2 serial circuit. If you see variable/different voltage, then there is resistance across those connections. I recently fixed a randomly flickering backlight with this problem ( [URL="https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-tvs-and-video-sources/3481098-vizio-e55-f1-dark-backlight-zones-led-failure-or-dimming-zone-driver?p=3486967#post3486967"]link[/URL]...

Thanks. So I guess important to replace with correct TVS (Transient Voltage Suppresser for those not reading prior posts) than just remove.

Also I guess valuable to salvage buffer boards from cracked screens for spare parts my spare buffer boards were older TVs and didn’t have this particular TVS....

UPDATE

Replacement ESD diode array ( [URL="https://www.mouser.de/datasheet/2/240/Littelfuse_TVS_Diode_Array_SP1064E_Datasheet-2509270.pdf"]link[/URL] ) came in. Replace D14. TV continues to work as if it was removed before but now with ESD protection. D15 had no OL issues and works. Was a mistake in prior measurement. Some people claim can remove and put on by soldering iron. Would need a really good micro pencil with a knife tip and probably some low melt solder. I just used hot air station (should protect the gold flex connection below from hot air).

These...

Yes, SJ was misleading on this one. Naturally I try to order LEDs before disassembly to avoid having parts opened and scattered while waiting for parts. Unfortunately encountered a mismatch on this one so alerting future repair efforts.

On dimming zones, E55-F1 Vizio spec also give misleading info (they say 10 zones) but clearly there are 12. I can test 12 independent strips (each one = 1 zone) with LED tester. Fully reassembled TV service menu backlight test shine all 12 zones independently (quickly so need to slow down video in post [URL="https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-tvs-and-video-sources/3481098-vizio-e55-f1-dark-backlight-zones-led-failure-or-dimming-zone-driver?p=3486967#post3486967"]#8[/URL])...

Please see attached. I looked at every service menu entry and can't find anything that looks like sync R, PSU BL. Also downloaded E70-C3 service manual with same service menu ( [URL="https://elektrotanya.com/vizio_e70-c3_led_tv_sm.pdf/download.html"]link[/URL] ) and unfortunately no description of service menu other than software update. If there is a step sequence or hidden menu, let me know. Thanks.

[URL=filedata/fetch?id=3487647&d=1729374926][ATTACH=JSON]{"alt":"Click image for larger version Name:\tIMG_3349.jpg Views:\t0 Size:\t4.75 MB ID:\t3487647","data-align":"none","data-attachmentid":"3487647","data-size":"thumb"}[/ATTACH][/URL]...

Yes, I see the test pattern steps and have tried them. Always setting back to default 0 (and factory reset sets to 0 as well). Not sure these are dimming settings. When smartcast is running, they do nothing. I don't see any other setting for dimming control in service menu. In regular system menu, I can set active dimming to off low med high and system has a default setting on these depending on picture mode. Factory reset (have done many times) always return these to defaults.

My repair on this backlight was down to just testing resistance across the LED strip connection. ohm test...

BTW, all this is the result of trying to reduce 1 labor step to avoid using human's dexterous fingers to click on a robust male/female connector pair and routing a wiring harness that has been matured for 1/2 century.

I'm involved in DIY Tesla car large battery repairs. Tesla also attempted to eliminate this human step and made a robot ultrasonic bonded voltage sensor monitoring flex + wires. We are now seeing thermal cycling and vibration breakage of the ultrasonic welds. Repair require far more labor than originally saved as Tesla decided to use sealant to glue the battery shut...

Fixed... for now haha. Jumpered +- across all 12 strip connectors.[LIST][*]Resistance is < 1ohm across all 24 connections.[*]LED tester reaches 18.5-18.6v instantly on all 12 strips[*]Backlight test in service menu just cycles all 12 strips (see video). Have another Vizio with active dimming and it does the same.[*]Also touched up backlight driver connector solder to avoid brittle lead free issue in the future.[/LIST]Maybe best to turn off Active Dimming? TV does get much brighter with AD on high so people probably prefer that.

[ATTACH=JSON]{"data-align":"none","data-size":"thumb","data-attachmentid":3486983}[/ATTACH]...

UPDATE:[LIST][*]Jumpered all the + side of all 12 LED strip connector and all resistance across connection is < 1 ohm.[*]- side are all < 1 ohm without jumper (will jumper it to be certain) so quite interesting all the failures are on the + side.[*]LED tester shows 18.5v on all strips from the LED rail connector.[*]Quite a few LED strip securing screws are loose. Backside of strip is double side taped down. Probably also result of high thermal cycling from dynamic dimming.[/LIST][URL=filedata/fetch?id=3486392&d=1729231376][ATTACH=JSON]{"alt":"Click image for larger version...

Found the problem and its the first time I've seen this one.[LIST][*]All LED strip test okay at 18.5v applying voltage directly onto the strip + - pads.[*]LED tester LED driver board connection shows variable voltage in some strips 19-25v[*]LED tester (self adjust voltage seeking target current) with changing voltage is due to changing resistance.[*]Found poor contact between LED strip and its connector. Am able to check resistance of this connection and its in many Ks or 1/2 M ohm. If I tin the LED strip contact or solder a jumper. The connection is reliably near 0 ohm. and LED tester reliably...

yes, I also guessed single MAC to outside since TV user manual said WiFi doesn't work if RJ45 is connected.



I forgot to share this TV has USB Debugging feature in service menu ( MENU + 4 + 2 + 1 + 0 ) If turned on, it will produce a system OS log file on the plugged in FAT32 USB. My log ( attached ) shows not finding WiFi and Bt HW as expected ( driver load fails )

Will report back after replacing main. Maybe I'll also try to reflow the SOC on this main to see any effect.

[ATTACH=JSON]{"data-align":"none","data-size...

• [LIST]
• Cable all isolated from chassis. Antenna is taped on and insulated. Also made sure cable plugs are not touching wifi/bt model EMI shield
• Crossing over each other at wifi+bt module seems to be from the factory with taped down cable and plastic cover mounts suggesting wasn't opened and moved.[/LIST][LIST]
• Fluxed and resoldered the module
• Hot air generally heating the module, communication line SMDs and power source circuit[/LIST]Unfortunately no difference. I did notice a few things[LIST]
• Alternating factory reset shows WiFiVendor = QCA (alternate times = No Vendor) which probably

...

Thanks to [USER="75051"]Diah[/USER], got M557-G0 LCD panel buffer board repaired and running ( [URL="https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-tvs-and-video-sources/3483720-vizio-m557-g0-1-2-panel-vghd-lc1-and-maybe-xon-vssq-lc2-problems?p=3483885#post3483885"]link[/URL] ) Next challenge is no WiFi/Bt despite module on the main board and getting 3.3v supply (3.45v measured)[LIST][*]TV Menu shows Network Access Point option (enet unplugged) but menu can't select that entry[*]Service Menu shows many Bt/Wifi info missing[*]Vizio...

Thank you much for the hint. Fixed, 2x diode shorts on D14 ESD diodes was culprit. Removed and shorted cap circuit nearby disappeared. TV works with no t-con signal masking. Also found same fix in this thread ( [URL="https://www.eevblog.com/forum/repair/tv-repair-identify-component-diode-(hisense-h65u7a)/"]link[/URL] ) Don't have 4264H ESD diode array ( [URL="https://www.mouser.de/datasheet/2/240/Littelfuse_TVS_Diode_Array_SP1064E_Datasheet-2509270.pdf"]link[/URL] from prior thread ) in my donor buffer board pile. Seems unnecessary but probably good to put good one back for...