Philips TV unknown pwm controller in PSU. - Page 1
Forum section: electronics / repair

author: eurgenca
author_rank: Regular Contributor
timestamp: January 08, 2021, 07:44:33 pm
content: Hello.I have philips tv 42pfs4012 chassis kts17.1e la. Found service manual but power supply only has shematic without part list.So I can't find any info for pwm chip.Can someone help please.Thanks, Sebastijan.

author: eurgenca
author_rank: Regular Contributor
timestamp: January 08, 2021, 07:52:29 pm
content: If this help.

author: fzabkar
author_rank: Super Contributor
timestamp: January 08, 2021, 08:36:33 pm
content: I couldn't find the part, but I expect it is made by NXP. The "t" looks like an NXP manufacturing site code.Something like this:https://www.nxp.com/docs/en/application-note/AN11588.pdf

author: eurgenca
author_rank: Regular Contributor
timestamp: January 08, 2021, 08:59:29 pm
content: Yeh, pinout is not same.Strange is that google can't find nothing. I try "qet, qet30r, qet50, 30r50" and completely nothing.

author: eurgenca
author_rank: Regular Contributor
timestamp: January 08, 2021, 09:38:45 pm
content: Hmm. I realize that this is generic chinese board and not made by philips.This MS3463S PB801 board share a lot of other manufacturer but all share same manual without part list. What chinese's trying to hide in this PSU?So far found this, same pinout.Can someone advise if one of them will do the yob.https://datasheetspdf.com/pdf-file/824155/LeadtrendTechnology/LD7530/1https://datasheetspdf.com/pdf-file/1246108/FairchildSemiconductor/SG6848TZ1/1And one morehttps://www.onsemi.com/pub/Collateral/NCP1251-D.PDFhttps://datasheetspdf.com/pdf-file/637352/FairchildSemiconductor/SG6859A/1https://pdf1.alldatasheet.com/datasheet-pdf/view/1221279/LEADTREND/LD7536R.html

author: Andy Watson
author_rank: Super Contributor
timestamp: January 08, 2021, 10:02:59 pm
content: This one has the "R" suffix.http://www.datasheet39.com/PDF/824157/LD5530R-datasheet.htmlBut otherwise appears very similar to the LD7530.

author: fzabkar
author_rank: Super Contributor
timestamp: January 08, 2021, 10:44:00 pm
content: See this thread:http://monitor.espec.ws/section27/printview274444.htmlThe OP seems to be saying that his MS3463S PCB had a chip marked "5A2R". That's an NCP1251BSN65T1G.

author: eurgenca
author_rank: Regular Contributor
timestamp: January 10, 2021, 10:23:34 am
content: Hello.O.k. I found this on aliexpress it seems that is replacement from serie N83Gxx, but guess what?Completely no data for this chiphttps://www.aliexpress.com/item/4001047685082.html?spm=a2g0s.8937460.0.0.98552e0etk44QzIt looks like this tv is going to trash.

author: Andy Watson
author_rank: Super Contributor
timestamp: January 10, 2021, 03:50:49 pm
content: Either, it is a direct replacement - in which case the existing datasheets apply, or it is not a direct replacement - in which case it is useless.Have you tried ebay ? Here is one (there are plenty of others), although I am sure you could do much better if you spent some time searching your local ebay.https://www.ebay.co.uk/itm/202856505223If you do not want to purchase via ebay use it as a source of contacts - try searching or contacting the vendors directly.If you want to substitute note that the LD5530R data sheetshintsthat the device is based on a UC384x (pin descriptions, pin 2, page 2).

author: fzabkar
author_rank: Super Contributor
timestamp: January 10, 2021, 06:32:35 pm
content: What is wrong with my suggestion?

author: eurgenca
author_rank: Regular Contributor
timestamp: January 10, 2021, 07:11:04 pm
content: I can use ncp1251x, but which one.1. there are 2 frequency 65 and 100 kHz2. what is the difference with protection, there are latch and autorecovery?I can use either LD5530R but I presum that I have only one try.

author: fzabkar
author_rank: Super Contributor
timestamp: January 10, 2021, 08:47:35 pm
content: "5A2R" is NCP1251BSN65T1G.

author: eurgenca
author_rank: Regular Contributor
timestamp: January 11, 2021, 07:42:13 pm
content: Parts ordered. Let's wait some time.

author: eurgenca
author_rank: Regular Contributor
timestamp: January 24, 2021, 08:02:38 am
content: Well. Parts arrived and PS works fine. I ordered LD5530RGL and for now looks good.Andy Watson and fzabkar thank's for help.