Help with the repair of the Philips Momentum 436M6VBPAB Monitor - Page 1
Forum section: electronics / repair

author: jottha
author_rank: Contributor
timestamp: April 10, 2025, 07:53:34 pm
content: Hello. I have a Philips 436M6VBPAB monitor.About 4-5 minutes after turning it on, it displays irregular horizontal stripes.Over time, these stripes become significantly more frequent.There are no abnormalities with the motherboard or power supply.Replacement boards are available for purchase, but is the power supply or motherboard defective?I would prefer to repair the defective board myself.It would be great if someone could help me.Regards, Jürgen

author: amyk
author_rank: Super Contributor
timestamp: April 11, 2025, 02:19:57 am
content: That sounds like a TAB bonding problem.

author: jottha
author_rank: Contributor
timestamp: April 11, 2025, 05:44:27 pm
content: Hello Amyk,thank you very much for the quick reply.Now I have the problem that I don't know what a tab bounding problem is, or rather, what tab bounding is, because I'm a novice when it comes to repairing TVs and/or monitors.Could you please explain this for me?Thanks.

author: tom66
author_rank: Super Contributor
timestamp: April 11, 2025, 06:12:04 pm
content: A 'TAB bonding' issue is a term that refers to a failure of either the bonding from the LCD panel driver ICs to the panel surface, or a failure of the ICs itself. Strictly speaking the latter is not a tab bonding failure, but the symptoms are common. Unfortunately, in either case, the fault is normally non-repairable - a few very skilled individuals can use re-bonding machines to fix this issue, but generally it's not accessible to the ordinary individual.In order to determine the fault, please show a clear image of the fault.

author: jottha
author_rank: Contributor
timestamp: April 13, 2025, 07:04:33 pm
content: @AmykOk, thanks.

author: jottha
author_rank: Contributor
timestamp: April 13, 2025, 07:08:02 pm
content: @tom66.One more question: Will the problem be solved if I replace the motherboard?

author: tom66
author_rank: Super Contributor
timestamp: April 16, 2025, 04:54:07 pm
content: Quote from: jottha on April 13, 2025, 07:08:02 pmNo, if the fault is with the panel, the monitor is done for, sorry, it will never be economical to repair.Post a clear picture of the fault if you want me to confirm it.

author: jottha
author_rank: Contributor
timestamp: April 21, 2025, 08:11:28 pm
content: @tom66I'm sorry, but I disassembled the monitor in the hopes of being able to repair it.It would be too much work to reassemble it now.

author: jottha
author_rank: Contributor
timestamp: April 23, 2025, 07:44:16 pm
content: Hello, here's an addendum to my question: Is it possible that the error is caused by increasing heat buildup in a component?Since the error always occurs minutes after powering on, and then it doesn't appear as static lines, but rather like a distorted TV signal.I would appreciate the opinion of an experienced user.Thanks and best regards.Jürgen

author: tom66
author_rank: Super Contributor
timestamp: April 23, 2025, 10:05:19 pm
content: The tab bonding failure can occur with heat, yes. This would result in lines appearing after only some time.If you want a diagnosis, you must post a picture of the display. I recommend you assemble the monitor into a close enough state so that you can safely power it up.

author: jottha
author_rank: Contributor
timestamp: April 24, 2025, 08:26:38 pm
content: Okay, I'll reassemble the monitor, but it will take a few days. Then I'll upload a picture of the problem.

author: daisizhou
author_rank: Super Contributor
timestamp: April 25, 2025, 12:13:28 am
content: Is the monitor backlight CCF type or LED type?

author: tom66
author_rank: Super Contributor
timestamp: April 25, 2025, 10:23:37 am
content: It's a 4K monitor.I don't know of any 4K monitors that use CCFL backlight. The backlight for a 4K monitor needs to be much brighter than FHD or lower because the pixels are less transmissive, and CCFL backlights would struggle to achieve that. LCD switched away from CCFL about 10 years ago now, around the same time that 4K started to come onto the scene. Adding in HDR further complicates things.

author: jottha
author_rank: Contributor
timestamp: May 04, 2025, 08:16:00 pm
content: Sorry I'm only uploading pictures now, but I had to be in the hospital in the meantime.The first image shows the monitor shortly after it was turned on.The second image shows it after a few minutes.I actually wanted to upload a video, but it would be too large.I hope it might help you figure out what the cause of the problem might be.

author: tom66
author_rank: Super Contributor
timestamp: May 04, 2025, 08:23:48 pm
content: Could you upload a video to a platform like YouTube? It is free to do so, you just need an account... It is hard to see what could be wrong.

author: jottha
author_rank: Contributor
timestamp: May 04, 2025, 08:34:33 pm
content: Hello, here is the link to the Youtube-Videohttps://youtu.be/SYl9xMkyyN4

author: tom66
author_rank: Super Contributor
timestamp: May 04, 2025, 08:41:39 pm
content: The video has been uploaded as private, you probably want to set it to public or unlisted.

author: jottha
author_rank: Contributor
timestamp: May 05, 2025, 06:12:18 pm
content: Good evening, the video is now visible to everyone! (It's my first video on YouTube...I didn't know how to set it up!)

author: tom66
author_rank: Super Contributor
timestamp: May 06, 2025, 06:36:28 pm
content: Hmm, that is a strange fault! I do not think it is the panel though, so that is good news. If you are prepared to do some diagnosis, I think it would be worth trying to heat up some parts of the monitor's circuit boards with a hair dryer on a low heat. The problem is likely occurring when things get hot, and by heating things up we can get a better idea of the likely cause of the fault. I would suggest only trying the main board and the T-Con board (if present). It is also worth checking the cable between the main board and T-Con board. If you need help identifying which board is which, post a clear picture of the back of the monitor showing all the boards inside.

author: jottha
author_rank: Contributor
timestamp: May 08, 2025, 07:37:41 pm
content: Since the monitor only has two boards, one of which is the power supply, only the other board remains.Heating it with a hairdryer isn't easy, since you can't reach the boards once they're reinstalled.I'll send you pictures of the motherboard; maybe you can see something on them.

author: jottha
author_rank: Contributor
timestamp: May 08, 2025, 07:42:36 pm
content: The first picture is from the internet.The other pictures (two from my previous post and two more from this post) show the defective motherboard.

author: tom66
author_rank: Super Contributor
timestamp: May 08, 2025, 09:42:01 pm
content: This doesn't look like a direct to panel main board, those normally have many ribbons. There likely is a T-con board of some kind but it may be behind shielding. I usually work on monitors and TVs on the dining room table, with a towel down to protect the screen.

author: jottha
author_rank: Contributor
timestamp: May 09, 2025, 08:36:01 pm
content: Yes, I also use towels and our kitchen table, but when I get to the board all other connections - ribbon cables, connectors etc. are removed and the screen is then not active.I think the monitor is something for the bulky waste.

author: tom66
author_rank: Super Contributor
timestamp: May 09, 2025, 11:21:02 pm
content: Well, if you feel you cannot fix it, then perhaps give it away on the local "Craigslist" equivalent, or eBay for 99p. Maybe someone else will, rather than let it become e-waste, seems like a shame!

author: jottha
author_rank: Contributor
timestamp: May 10, 2025, 06:10:43 pm
content: Yes, you're right, it hurts my soul too. But the monitor is so big that I can't ship it because I don't have any packaging left, and there are few buyers nearby.I'll think about it.