Re: Phillips PSU bad capacitor
this is likely 47uF and 33uF (DPS-298CP-A).
OobabeloO
Member
Last Activity: 11-09-2018, 12:25 PM
Joined: 09-09-2018
Location: Bruxelles
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Re: Philips 37PFL9604/H12 : backlight will switch off after some time on
I swapped the IC601 (DDA002C) with another one and the TV works without issue since 15'. Could it be that it was faulty or of very low quality ?Leave a comment:
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Re: Philips 37PFL9604/H12 : backlight will switch off after some time on
This is DDA002C. It drives the whole fets stage.Leave a comment:
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Re: Philips 37PFL9604/H12 : backlight will switch off after some time on
I double check with the DMM that the contact are correct for IC601....Leave a comment:
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Re: Philips 37PFL9604/H12 : backlight will switch off after some time on
sorry, I forgot the multiplier:
9 to 10 = 6 to 5 = 16 ohms
9 to 8 = 6 to 8 = 10 to 8 = 8 to 5 = 10 Kohms
I have no ESR tool, but the cap mesaure 120uF and looks intact (no physical damage).
on the picture, you will see that:
- I changed the HV ceramic caps,
- I changed the mosfets
- I changed the IC601 (not a great job)...Leave a comment:
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Re: Philips 37PFL9604/H12 : backlight will switch off after some time on
I must add than since yesterday, the backlight will stay on for few seconds only.Leave a comment:
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Re: Philips 37PFL9604/H12 : backlight will switch off after some time on
There are 9 contacts on the HV transformers. Upper ones, next to HV caps are numbered 5 to 6.
9 to 10 = 6 to 5 = 16 ohms
9 to 8 = 6 to 8 = 10 ohms
Regarding the BL_ON, there are about 26mV when the screen is lighted or when the issue happens.Last edited by OobabeloO; 09-18-2018, 01:13 PM.Leave a comment:
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Re: Philips 37PFL9604/H12 : backlight will switch off after some time on
There are 9 contacts on the HV transformers.
I do not see the screen as yellowish when lighted, but the backlight will not stay long enough for me to use a white source to check.
I'm only referring to the white inside the Philips logo....Last edited by OobabeloO; 09-18-2018, 01:38 PM.Leave a comment:
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Re: Philips 37PFL9604/H12 : backlight will switch off after some time on
I have attached several picture of the visible side of the PSU.
As for testing the HT transformer, I'm not sure about how I should proceed, What would be my reference point : one winding with another ?
Also, in my initial post, I said that I replaced the ceramic caps on the HT side. I miswrote the values : those are 33 and 47 microfarads....Last edited by OobabeloO; 09-17-2018, 04:07 PM.Leave a comment:
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Re: Philips 37PFL9604/H12 : backlight will switch off after some time on
thanks for your help.
do you mean that the resistance measured should be approximately the save at each output ? what would be a "normal" absolute value ? as you may know, there are 2 different transformers on this PSU.
also, why tracking the BL_ON, to identify if it is an issue from the main board ?Leave a comment:
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Philips 37PFL9604/H12 : backlight will switch off after some time on
Hi,
My TV (Philips 37PFL9604, chassis Q549.2LE) has an annoying backlight issue since a few days.
It will power up flawlessly but, after a certain amount of time, the backlight will switch off for a second, then switch on again. It will happen a few time until the screen goes black totally.
When the backlights are on, I cannot see any dimming or artefact on the screen, thus I would not bet on a CCFL issue. The TV has been used (display on) for a bit more than 5000hours.
I used a flashlight to check that the image was still present and... -
Re: [Philips TV] 47PFL5604H backlight/inverter
Hello Felix,
did you manage to find the issue with the backlight ?
I'm facing a similar issue on my DPS-298CPA board : the TV will work for a given time, then the backlight will switch off and back, etc.. and then off until I restart the TV (cold boot).
I already changed all mosfet, the HT caps as the IC that drives the mosfets to solve an annoying clicking sound (and this was indeed the cure).
Regards,Leave a comment:
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