Philips 42PFL7432D/37 No Power Error Code 8

[A Man]

Hello all! This chassy is Q532.1U LA. The unit goes into protection immediately upon connection to power and the red LED flashes 8 times. (I haven't touched this set in several months but the last time I tried to power it up, the screen seemed to light up a little though nothing was displayed and I was getting an error code 28. Don't know if that is related or not.) I can use the SDM to bypass the protected start-up and the LED changes to blue but that is all: no Ambilight, no backlight, nothing changes that I can tell since I do not have a source connected. I don't know the operating principles well enough to know what to check next. I have downloaded the service manual which indicates Code 8 as a problem with the DC-DC Converter but am not sure exactly where to start.

I've looked for the obvious bulging caps but most of them are Rubycon although there are a few Lelons. No burned traces nor components except a little bit of burning on the top posts of component 5401. I think it's a choke according to the schematic, but I'm not sure if it will cause this code... I'm 20+ years away from my last electronics class lol. I'm googling as I write this so maybe I'll have learned something helpful by the time someone posts.

I've added pictures of the tops of the boards. Let me know if we need the bottoms. On the SSB I have +12V and +5V on connector 1B40. What does that mean?

Thanks!

Adrian

[tom66]

Re: Philips 42PFL7432D/37 No Power Error Code 8

This is one of those Philips oddities or abominations (take your pick) which has some power supply stuff on the main board for some reason.

If possible, can you check if this supply is working, any visible outputs for it nearby? Good places to start are cathodes of diodes on the SMPS outputs.

Also do any of the five lights near the "Cyclone II" device light up? The Cyclone II is an FPGA - a type of programmable logic IC. If it is not working, it could indicate a fault with the DC/DC converter.

[A Man]

Re: Philips 42PFL7432D/37 No Power Error Code 8

If possible, can you check if this supply is working, any visible outputs for it nearby? Good places to start are cathodes of diodes on the SMPS outputs.

Also do any of the five lights near the "Cyclone II" device light up? The Cyclone II is an FPGA - a type of programmable logic IC. If it is not working, it could indicate a fault with the DC/DC converter.

I'm not sure which diodes you are referencing. Which ones might that be? None of the five LEDs come on. I do have +12 and +5 on 1B40 which is supplied by the SSB. I'm attaching a page from the service manual which I believe is pertinent.

[A Man]

Re: Philips 42PFL7432D/37 No Power Error Code 8

Anyone have any input on this power issue? It's the Q523.1U-LA chassis as used in 42PFL7432D/37?

[Losdog]

Re: Philips 42PFL7432D/37 No Power Error Code 8

sorry for the late reply.
i replaced the entire board and that took care of the issue.

im my instance there was not wiring diagram for said board. the service manual listed it as a "black box" for service meaning (to me) that support was not available nor diagrams.

[A Man]

Re: Philips 42PFL7432D/37 No Power Error Code 8

Thank you but I have the 42 inch model which is not a black box. I have the schematics for the power supply, I just don't know how to proceed with troubleshooting it. Any ideas?

[tibimakai]

Re: Philips 42PFL7432D/37 No Power Error Code 8

What the 8 blinks mean?
I have a 7422D/37 model, with no life at all.

[budm]

Re: Philips 42PFL7432D/37 No Power Error Code 8

According to the service manual: it can be due to DC-DC power supply for 1V2, 1V4, 2V5, 3V3. So those voltages need to be checked.
See attached diagrams.
The service is really a pain to locate the needed diagrams.

[A Man]

Re: Philips 42PFL7432D/37 No Power Error Code 8

Thank you for this information. I still need a little assistance to understand.

I powered on the set, measured on caps 2U03 & 2U93 as shown in the picture, and read 12.8 on my meter. Is this the correct way to measure? I also had the voltage when I moved the COM probe to chassis ground. However, this power went away as soon as the PSU relay clicked off.

From page 34... " If the input voltage of DC-DC converters is around 12.7V
(measured on decoupling capacitors 2U03/2U93/2U6S
and 2U6R) and the enable signals are low (active) then the
output voltages should have their normal values.+12V and
+5V-POD supplies start-up first (enabled by POD-MODE
signal from the stand-by microprocessor). There is a
supplementary condition for +12V to start-up: if +5V-POD
doesn't start up due to a local defect then +12V will not be
available, as well."

Where would I check these output voltages?

Page 141 also deals with the DC-DC converters; it is attached to post #3.

[budm]

Re: Philips 42PFL7432D/37 No Power Error Code 8

At this point, you will look at DC-DC of page 63, 67, 79 that I red circled for the test points and locate those points on the circuit board which will not be easy but you will have to find them, and see if those voltages are present.