Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

[Robb]

My Hitachi P50S602 plasma powers on with that familiar white snow static then powers off after a few seconds and the power indicator blue light blinks five times & repeats. All the capacitors and resistors look fine. The fans also turn on and Vs & Va voltages are correct for the few seconds that it has power. When I unplug XSUS from the PSU, the tv does not power on at all and the blue light blinks 3 times. The only fuse I've found (on PSU) is good.

According to the service manual (PDP panel self diagnosis), the blue power indicator light blinking five (5) times means: 1st possible cause - ADM, ABUS; 2nd possible cause - XSUS, Logic, PSU.

I am not sure what ADM is or how to test it, ABUS or Logic. The static is also throwing me off too as it looks like it's not getting a signal, but I have tried a few different inputs along with trying to change the inputs modes.

Does anyone have any similar experience with this or similiar tv or have any ideas on what to check next? Thank you in advance.

[Sparks88]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

ysus and the 2 largest caps on power board in uk they are rated at 400v maybe different in US

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

ABUS runs the length of the plasma panel. It has the address/data drivers on it which are bonded to the panel and non-replaceable. If it is true ABUS fault then it may be a bad panel.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Thanks for the responses. I think I figured out that ADM stands for Address Driver Module, but I don't know where it is located (not identified in service manual) or how to test it. There are six ABUS panels, three on top and three on bottom and all are connected to the panel by ribbons. The top row and bottom row are connected to each other and both are powered by the XSUS e.g. XSUS>ABU-UR(upper right)>ABUS-UC(upper center)>ABUS-UL(upper left).

If I unplug the power from ABUS-UC>ABUS-UL and press the power button, the panel starts to display what kinda looks like deep space snow and then shuts down (no change/original problem). However, when I unplug ABUS-UR>ABUS-UC and press the power button, the display doesn't start or show anything; the blue led just blinks three times & repeats.

Not sure if that proves anything, or not; other than I don't know what I'm doing

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Weird, I've only been able to find one guy on the web who claims to know how to "fix" Hitachis. He used to be a Hitachi repairman and he said all they do is swap boards until it works. Not very practical from a do-it-yourself perspective, imo. I guess I'll probably end up putting it on craigslist since the prospect of replacing ADM (whatever that is), ABUS, XSUS, Logic & PSU is out of the question, especially, considering it's age. However, at this point, smashing it into pieces might be more rewarding. I wish the screen never displayed anything, it would be alot less frustrating.

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

I understand your frustration. I have never willingly tackled a big Hitachi, they are buggers to troubleshoot. I've worked on a few older 37/42" Fujitsu-Hitachi plasma panels in Philips plasma TVs though, but they're a lot different. I highly suggest you do not smash the panel... because then it truly will be worthless!!

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

I decided to put the back cover back on and walk way for awhile. Perhaps this will be a great learning catalyst for me. I'm going to brush up on testing capacitors, transistors, resistors, etc. Hopefully, I will discover a common sense approach that will evince the fault despite Hitachi's proprietary interests. I hope to be able to report back, soon. Cheers

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Below is a picture of what the panel looks like for the three seconds before the TV shuts itself off.

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Looks like PDP maldischarge could be Y-sus fault.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Hmm, according to the service manual (p. 27), the five blue led blinks indicates 1) ADM, ABUS 2) XSUS, Logic, PSU.

Unfortunately, I don't think this model &/or brand accommodates the remove the Y-sus and see if it powers on correctly method of diagnosis. If I disconnect the Y-sus power, the blue led blinks three times & the screen displays nothing & the fans don't spin for the usual three secs before it shuts down.

I guess I should start testing the components on the boards soon. Do you know what components usually go bad on Y-sus & X-sus boards?

I'm not sure if this is important, but there is a burnt smell & slight discoloration on the underside of the X-sus around the R154, R155, R156 & R163 resistors (see pics), however, they all have the same ohm reading in circuit & one measured correctly out of circuit.

Thank you for your continuing input, Tom...it sure helps to bounce ideas off someone with experience.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

I finally found a way to get the blinking light to stop. If I unplug the Logic Board and hit the power button, the TV's LED turns solid red, then, solid blue, then turns off without ever blinking. Does anyone know if that means the Logic Board is defective? When I unplug any other board, the only thing that changes is the number of blinks.

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

The logic board will likely be involved in detecting many of the faults so no it does not necessarily indicate the logic board is the cause.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

The logic board will likely be involved in detecting many of the faults so no it does not necessarily indicate the logic board is the cause.

Thanks. Is there a way to test it? The Logic Board is indicated as a possible cause of failure according to the five blinking LED code.

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Without schematics not really.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Guess I'll assume the Logic Board is good. (Facepalm)

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

I know I'm grasping at straws but I found another anomaly. There are three HDMI ports and I plugged a playstation into all of them to see if anything would happen. Two ports did nothing new, just the usual power on with multcolored maldischarge. However, one port produced a partial image (see below). Could this mean there is an issue with the Main Board?

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

It probably indicates the TV was originally set to that HDMI port and that bright image information can be displayed. I would be thinking more Y-SUS than X-SUS in this case but I'm not certain.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

Yes, that would make sense. Are there particular components that usually go out on the Y-SUS that I could check to see if it is in fact the Y-SUS? The TV is not staying powered on when I unplug the Y-SUS or X-SUS. Thank you for your faithful assistance Saint tom66!

[tom66]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

I have little experience with Hitachi plasmas. You could use an oscilloscope to test the output of each board.

[Robb]

Re: Hitachi P50S602 Powers On/Off Blue Light Blinks 5 Times

I guess it's time to get an oscilloscope. Do you know if the USB 2 channel models work well? They seem to be the cheapest...sure wish there was a hackerspace in my area, like Noisebridge in San Francisco.

Edit: I guess I could just use the vertical coil wires from a CRT TV http://www.instructables.com/id/How-...-Oscilloscope/