Need help identifying smd

[caphair]

Re: Need help identifying smd

Idk if this means anything but, I shorted B to E of Q5 to see what would happen because I thought that transistor might be at fault, and I had same symptoms minus backlight.

So it seems that if the disc drive doesn't power up then the command for backlights doesn't get sent. So does this mean Q5 must be getting its on signal from somewhere? There's 5v on its base when the power button is pressed so I figured that 5v would turn it on?

[caphair]

Re: Need help identifying smd

Ok this is bizarre. The disc eject button is functional with unit on or off. So I tried pressing it while powering on the unit and I got it to turn on every time if the eject button is first pressed followed by the power button

[budm]

Re: Need help identifying smd

No if it's working the voltage goes up then settles at 10v and when it's not working it stays at less than 1v

But that should not stop you from getting sound or what ever since that is just the backlights circuit for the LEDs, so if you also do not get any sound then the problem is some where else.

[caphair]

Re: Need help identifying smd

It seems that if the disc drive doesn't initiate during boot up then there's no display. It's odd that hitting eject then immediately powering unit on gets it to work every time

[fzabkar]

Re: Need help identifying smd

Does the power button have a dual function? For example, I notice that some units have a Power/Mute dual function.

Do you have a remote control for this unit? If so, does it behave properly?

Can you wake up the display if you insert a USB stick?

[caphair]

Re: Need help identifying smd

Power button does have dual function. When unit is on and power button pressed it toggles through various inputs, i.e. Radio, USB, aux 1/2

It does have a remote control and yields same result with it.

What do you mean by wake up the display with a USB?

[fzabkar]

Re: Need help identifying smd

Here is a service manual for a device that appears to have many similarities to your own (Premier SCR-4710TVD):

https://cdn.badcaps-static.com/pdfs/...9b02464af4.pdf
http://www.manualslib.com/download/7...r-4710tvd.html

Page 60 of the PDF has the same TFT on/off circuit as yours.

The PCB labels are very similar in format to your own, so it appears that the PCBs may be manufactured or designed by the same company.

Note that power sequencing (page 53) is done by a second processor (R5F21266):



It might be worth investigating the Premier product range in case they have an identical product under a different badge, perhaps with slightly different cosmetics.

[fzabkar]

Re: Need help identifying smd

Another manual:

http://www.manualslib.com/manual/101...r-4709tvd.html
https://cdn.badcaps-static.com/pdfs/...b097587727.pdf

FWIW, the following device can switch off the display while the audio remains on.

http://www.manualslib.com/manual/914...r-2067tft.html
https://cdn.badcaps-static.com/pdfs/...4e38f7b553.pdf

Display ON/OFF Function:

In Disc mode, swing the SEL knob briefly in the direction of APS/DISP to turn off the display image (the monitor on the unit only) , the sound will stay on. (Swing it again to resume the playback picture mode.)

Page 49 of the SCR-4710TVD manual shows the SPHE8202T SoC.

[caphair]

Re: Need help identifying smd

That SCR model is VERY similar I think the only difference is the screen size but looking at the manual the functions and display icons are the same.

Thanks for all your findings, how'd you find these btw?

In that SPHE8202T chip what should I be looking for? It seems that the DVD drive needs power first before display comes on but not sure what to look for exactly in terms of testing. I'm not seeing the power sequencing you mention?

Should I be looking at these circuits?

[fzabkar]

Re: Need help identifying smd

The KB_DET_EJ signal appeared to be unique, so I searched for that.

There are similarities between your unit and the SCR device, but they are not the same. For example, the backlight driver IC is U2 in the manual and U13 on your PCB. Your PCB is 12-K7700-3FS whereas those in the manual are 12-K4323-172, 12-K4323-KE2, 12-D4321-HP5. Therefore I would be careful when comparing the two devices.

ISTM that your problem is a difficult one. I would start by familiarising myself with each of the components and determining their function, ie start with a block diagram. Then I would measure the voltage test points in standby mode. Next see what happens to these same voltages when you operate the eject button, and then after you push the power button. I would also check the reset logic on page 50.

ISTM that the R5F21266 IC decodes the keypad and the IR remote rather than the SPHE8202TQ, so it is the master MCU. The SPHE8202TQ is a slave.

[fzabkar]

Re: Need help identifying smd

Yes the part number is le2j

FSP3300 -> marking LAYMX (YM = Year /Month, X = internal code)
FSP3301 -> LBYM
FSP3304 -> LCYM
? FSP3305 -> LE2J -> part number = LE, Y = 2012, M = October

FSP3305, Foslink Semiconductor / Vivichip Electronics, fixed frequency white LED driver, TSOT23-6L:
http://www.chinadmd.com/file/vuuuui3...sixwz36_1.html

https://cdn.badcaps-static.com/pdfs/...97ef367ef5.pdf (FSP3301)

(FSP3304)
https://cdn.badcaps-static.com/pdfs/...c66e861d91.pdf (FSP3300)

[caphair]

Re: Need help identifying smd

Thank you so much for all your findings. Appreciate it. Earlier I was looking at the power on/acc det circuit and all the voltages were where they needed to be during my tests even with no display.

The only difference I noticed when it worked and when it didn't is that standby voltages in the circuit at c124/c125 were .90v when it worked and also as I pressed eject first. When it didn't work properly there was .70v there.

Out of curiosity I tried replaced c125 as it was an electrolytic but still same issue. It seemed too complicated tracing down anymore so I'm just going to live with pressing eject followed by power button for now.

Thanks again!

[caphair]

Re: Need help identifying smd

Can I ask how you're finding information for ICS and such? When I do a google search I don't get anything useful

[fzabkar]

Re: Need help identifying smd

I search for PDFs using Google's search filters:

http://www.google.com/search?q=filet...number+here%22

The FSP3305 was listed in the SCR manual, so I looked for that first. I couldn't find its marking code, so I looked for its stablemates.

[caphair]

Re: Need help identifying smd

Can someone help me understand this circuit. I'm confused how both 5v and 12v are connected to same transistor Q63. Is 5/12v flowing through the same circuit when it's turned on?

[stj]

Re: Need help identifying smd

that has to be wrong!

[caphair]

Re: Need help identifying smd

that has to be wrong!

?