diff --git a/content/projects/repair-philips-42pfl6057h-12/bga-cracked.jpg b/content/projects/repair-philips-42pfl6057h-12/bga-cracked.jpg new file mode 100644 index 0000000..4733cc7 Binary files /dev/null and b/content/projects/repair-philips-42pfl6057h-12/bga-cracked.jpg differ diff --git a/content/projects/repair-philips-42pfl6057h-12/featured.jpg b/content/projects/repair-philips-42pfl6057h-12/featured.jpg new file mode 100644 index 0000000..63723bc Binary files /dev/null and b/content/projects/repair-philips-42pfl6057h-12/featured.jpg differ diff --git a/content/projects/repair-philips-42pfl6057h-12/fusion-soc.jpg b/content/projects/repair-philips-42pfl6057h-12/fusion-soc.jpg new file mode 100644 index 0000000..590dffd Binary files /dev/null and b/content/projects/repair-philips-42pfl6057h-12/fusion-soc.jpg differ diff --git a/content/projects/repair-philips-42pfl6057h-12/index.md b/content/projects/repair-philips-42pfl6057h-12/index.md new file mode 100644 index 0000000..c6eb3ac --- /dev/null +++ b/content/projects/repair-philips-42pfl6057h-12/index.md @@ -0,0 +1,85 @@ ++++ +date = "2019-02-10" +title = 'Repair: Philips 42" 3D LED TV with Ambilight' +tags = ["repair", "audiorepair", "philips", "tv"] +categories = [ "Audio Repair" ] +summary = 'Last week I started a new repair project: a 42" Philips TV. The power supply was obviously defect, but I ran into another problem as well...' +[image] + focal_point = "Center" ++++ + +I've done the occasional television repair in the past. Mostly Philips TVs with the '3 blinks' problem. When the power supply of a +Philips TV is defective, the main board will detect this and blink the stand-by led 3 times to indicate this problem. Power supply issues +I can fix - mostly. + +So, I found this Philips 42PFL6057H/12 TV on Marktplaats. Instead of the '3 blinks', this TV did absolutely nothing. Another clue that +the power supply is probably toasted. + +## Step 1 - Open it up + +First thing is to remove the back cover of the TV. There are a dozen or so screws on the back. These, together with two cables for the +buttons and ambilight, expose the power supply board and main board. + +The exact workings of how a Philips TV boots up when power is first connected is a bit more complex than what I'll describe here (read the service manual if you're +interested). When the power cord is connected, the power supply will generate a 3.3V stand-by voltage. This is enough to power the 'Fusion' chip +on the main board. The main board will then signal the power supply to start the 12V rails. + +So, the first order of business is to check if the 3.3V is there. It wasn't. Careful probing revealed a shorted dual-diode package. Luckily, I +was able to replace this part, as another power supply board from a previous repair had a similar dual-diode. + +This brought back the 3.3V, but now I _did_ get the 3 blinks, as the power supply was not able to provide 12V. Some further investigation +revealed that one of the control ICs on the power supply board seemed damaged as well. This part is hard-to-get and I opted to purchase +a replacement power supply board. + +## Step 2 - Why won't it work!? + +With the power supply board replaced, I could measure 3.3V and 12V from the power supply. However, the stand-by LED wouldn't turn on. +The TV _would_ respond with a blinking LED when I used the remote control on it - but it would _not_ turn on. + +Some googling revealed that this is a main board defect and can't be repaired. It's recommended to replace the main board. + +Well, I already replaced the power supply board, and I really didn't want to add further costs to this repair. Looking at the +main board, it's not very complicated. There are some peripheral connectors and support ICs, an audio section, and this big +BGA Fusion SoC. It's heatsinked on the front. On the back a piece of thermally conducting foam was used to sink some heat into the +metal chassis of the TV. + +So - nothing is obviously burnt. The TV does power up (so the Fusion SoC must be doing _something_), but it won't turn on. + +If there were to be a problem, my guess would be that the Fusion SoC suffered some thermal stress and any one of the BGA +connections might have been damaged. + +BGA (Ball Grid Array) is quite simple. The IC and PCB have solder pads and you sandwich small balls of solder between +them to make an electrical connection and secure the IC in place. This works great for SMD assembly of ICs with a +high pin count. + +One problem is thermal stress. When the IC generates heat, the PCB expands - and shrinks again when it cools off. In +the long run this may also cause stress to the miniscule solder balls. + +I found this photo on the internet that shows the exact problem. I don't have the equipment to inspect BGA's like this. + +![A cracked BGA solder ball](./bga-cracked.jpg) + +## Step 3 - Reflow + +At this point the main board is unusable. I can either replace it or attempt to fix the possible solder ball issue I +suspect. + +Feeling adventurous, I removed the main board and powered up my heat gun. I have one of those (cheap-ish) soldering +stations that come with an old fashioned iron _and_ hot air. I removed the heat sink and started carefully heating +up the IC. I tried measuring the surface temperature of the IC with my infrared meter, but I did not measure +above 160°C - too low to melt solder. Then I noticed that the solder on nearby resistors did melt. + +![The actual Fusion SoC](./fusion-soc.jpg) + +I stopped heating the board and let it cool for a few minutes. Re-installed the board and all the cables. Plug +in the power. Press the power button. And there it was. A working TV. + +## Step 4 - Cleaning up + +The ceramic heatsink on the Fusion SoC was attached with adhesive heatsink tape. It didn't stick. Luckily there +were mounting holes around the IC, so it was easy enough to construct something to keep the heatsink firmly +attached. + +Next, reinstall the back panel and reconnect the Ambilight cable. And I've got a new TV :-) + +![Working TV](./featured.jpg) diff --git a/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hu3f4802d3ceb32ad308c79837920c8f98_380328_540x0_resize_q75_box.jpg b/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hu3f4802d3ceb32ad308c79837920c8f98_380328_540x0_resize_q75_box.jpg new file mode 100644 index 0000000..38a9e83 Binary files /dev/null and b/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hu3f4802d3ceb32ad308c79837920c8f98_380328_540x0_resize_q75_box.jpg differ diff --git a/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hu3f4802d3ceb32ad308c79837920c8f98_380328_680x500_fill_q90_box_center.jpg b/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hu3f4802d3ceb32ad308c79837920c8f98_380328_680x500_fill_q90_box_center.jpg new file mode 100644 index 0000000..6ea4d29 Binary files /dev/null and b/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hu3f4802d3ceb32ad308c79837920c8f98_380328_680x500_fill_q90_box_center.jpg differ diff --git a/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hu3f4802d3ceb32ad308c79837920c8f98_380328_800x0_resize_q75_box.jpg b/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hu3f4802d3ceb32ad308c79837920c8f98_380328_800x0_resize_q75_box.jpg new file mode 100644 index 0000000..bf3edc3 Binary files /dev/null and b/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hu3f4802d3ceb32ad308c79837920c8f98_380328_800x0_resize_q75_box.jpg differ diff --git a/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hud4daa403d19f17e5d9269a920ed64dd7_1219518_540x0_resize_q75_box.jpg b/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hud4daa403d19f17e5d9269a920ed64dd7_1219518_540x0_resize_q75_box.jpg new file mode 100644 index 0000000..e875d5d Binary files /dev/null and b/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hud4daa403d19f17e5d9269a920ed64dd7_1219518_540x0_resize_q75_box.jpg differ diff --git a/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hud4daa403d19f17e5d9269a920ed64dd7_1219518_680x500_fill_q90_box_center.jpg b/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hud4daa403d19f17e5d9269a920ed64dd7_1219518_680x500_fill_q90_box_center.jpg new file mode 100644 index 0000000..e3911f2 Binary files /dev/null and b/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hud4daa403d19f17e5d9269a920ed64dd7_1219518_680x500_fill_q90_box_center.jpg differ diff --git a/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hud4daa403d19f17e5d9269a920ed64dd7_1219518_800x0_resize_q75_box.jpg b/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hud4daa403d19f17e5d9269a920ed64dd7_1219518_800x0_resize_q75_box.jpg new file mode 100644 index 0000000..4dd8394 Binary files /dev/null and b/resources/_gen/images/projects/repair-philips-42pfl6057h-12/featured_hud4daa403d19f17e5d9269a920ed64dd7_1219518_800x0_resize_q75_box.jpg differ