My Hitachi 50SBX70B lost power within seconds of plugging in, all the green LED's lit for a flash then went out slowly. Only the Red LED (D912) labeled Protect LED is blinking. I checked pico fuse E994 and it's OK, also C701 seems to be OK since I don't see any burn marks.
Any help is appreciated.
Thanks,
Tim
Symptom: BLOWS E994
Cause: DEFECTIVE D604
Symptom: BLOWS I401 EVERY FEW WEEKS
Cause: DEFECTIVE C410
Symptom: DARK PICTURE
Cause: DEFECTIVE 3D/YC COMB FILTER
Symptom: DARK PICTURE
Cause: DEFECTIVE C724
Symptom: DIGITAL CONVERGENCE WON'T ADJUST
Cause: DEFECTIVE DCU
Symptom: E994 KEEPS BLOWING
Cause: DEFECTIVE C701
Symptom: INTERMITTENT COLOR ON ALL INPUTS
Cause: DEFECTIVE IY01
Symptom: INTERMITTENT REMOTE FUNCTIONS
Cause: DEFECTIVE IR HM01
Symptom: INTERMITTENT REMOTE FUNCTIONS
Cause: DEFECTIVE D029
Symptom: INTERMITTENT VIDEO
Cause: DEFECTIVE 3D/YC COMB FILTER
Symptom: LOSS OF SYNC
Cause: DEFECTIVE 3D/YC COMB FILTER
Symptom: NO AUDIO
Cause: NEED TO RESET EEPROM I004
Symptom: NO CLOCK/SLOW CLOCK/CAN'T ADJUST CLOCK
Cause: DEFECTIVE D031,R0H8,Q018
Symptom: NO CONTROL OF BLUE COLOR
Cause: DEFECTIVE D511
Symptom: NO FRONT CONTROLS FUNCTIONS/REMOTE OK
Cause: DEFECTIVE DM04
Symptom: NO HOR SYNC
Cause: DEFECTIVE I008
Symptom: No Horizontal Sync. When PinP is called up, main picture may lock up for a 8 moment, then it goes back out of sync.
Cause: I008 defective (Sync Switch)
Symptom: NO LEFT CHANNEL
Cause: DEFECTIVE I401
Symptom: NO OSD
Cause: DEFECTIVE D716
Symptom: NO OSD
Cause: DEFECTIVE I102
Symptom: NO PICTURE
Cause: DEFECTIVE 3D/YC COMB FILTER
Symptom: NO POWER
Cause: DEFECTIVE I912
Symptom: NO REAR AUDIO
Cause: DEFECTIVE IS11
Symptom: NO REMOTE FUNCTIONE/FRONT CONTROLS OK
Cause: DEFECTIVE IR HM01
Symptom: NO REMOTE FUNCTIONS/FRONT CONTROLS OK
Cause: DEFECTIVE DM11
Symptom: NO SOUND
Cause: DEFECTIVE I401
Symptom: NO TUNER AND ALL INPUTS
Cause: DEFECTIVE IYO1
Symptom: OSD LATCHUP
Cause: SEE PTV98-4B
Symptom: PICTURE PULLS
Cause: DEFECTIVE D702,D703,D704
Symptom: RANDOM CHARACTERS ON SCREEN
Cause: NEED TO RESET EEPROM I004
Symptom: REPLACED DCU/RECONVERGED/NO MAGIC FOCUS
Cause: DID NOT INITIALIZE SENSORS
Symptom: RK46 VERY HOT/STK'S HAVE BEEN REPLACED
Cause: DEFECTIVE DCU
Symptom: SHUTDOWN
Cause: DEFECTIVE I401
Symptom: SHUTDOWN
Cause: DEFECTIVE I601
Symptom: SHUTDOWN
Cause: DEFECTIVE C715
Symptom: SHUTDOWN/OPEN E995,E996
Cause: DEFECTIVE T702
Symptom: SMEARED PICTURE
Cause: DEFECTIVE 3D/YC COMB FILTER
Symptom: SNAPS/BLOWS Q777
Cause: CRT ARCING
Symptom: WEAK COLOR
Cause: DEFECTIVE 3D/YC COMB FILTER
Symptom: WON'T HOLD CHANNEL MEMORY
Cause: NEED TO RESET EEPROM I004
Symptom: WON'T HOLD CHANNEL MEMORY
Cause: DEFECTIVE EEPROM I004
Symptom: NO AUDIO
Cause: Q013
Symptom: SHUTDOWN
Cause: Q777,I901
Symptom: SHUTDOWN
Cause: E994,D724
Yes best idea is to call the guy to come see it its not worth the trouble on here to go though everything and replece some ansews are stupid as i can see also this problem is still visable to us unless some one is rated a fixya ok thanks for your time have a great day from chris07551
The timer/standby indicator blinks for
about 30 seconds then goes to the self-diagnosis function. Something is
wrong with the video. Check video out, Q705, 732, 761 and other components
on the C board, also check Q218, 219, 220 on the A board. Also unit be in
IK
blanking, try turning up screen slightly.
~KEEPS US UPDATED.
Calling a service technician is much advisable.as he will also detect the other problems that you can face further in your device and that will make the unit perfectly all right.
Hi,
I want you to check these......
Pico fuse E994 open?
The +120VDC indicator LED D940 was unlit?
you said that the "protect-mode" D912 was flashing....
Check whether the small blue 2KV scan disc cap hidden under the larger ones
had arced internally: C707 "102 / 2KV"C707.
Thanx for using fixya,
Waiting for your reply.....
Good luck.
Try to replace the ignition board its the faulty in this casse cuz its not giving the signal to the whole borad to initiat the tv.
The condition of your TV called power supply overcurrent shutdown. The TV is going into a protection mode to prevent further circuit damage. That's why it will not turn on or not powering up,only a red standby light. I would concentrate on the power supply section board. Bad regulation of the incoming voltage could caused this issue although,there is a capacitor across the incoming line and nuetral.Maybe its leak or dry up and cause the problems,change it out with one of identical rating .I would probably also check the flyback circuit and flyback transformer although now you are getting into dangerous area,especially if you have no electronic experience background. It could be also be a loose ,crack or cold solder joint,a blown fuse,fusible links or other component .It could be one of several boards.Unfortunately the level of sophistication on these TV make it virtually impossible to diagnose them further without taking them apart and probing around with a multimeter and other tools.
Hope this may help you..
Regards,
VOTIT
Hi,
If you don't have schematic of your Hitachi 50XBS70B, download it HERE by entering model number in search box. Next page will show you service manual files, download all 7 parts and extract with WinRAR software.
This will enable you to go through troubleshoot chart in service manual and locate and test defective parts.
Regards,
You don't need to pay for service manual on that site as its free there.
Just give model number in search box and download all 7 parts of file free.
Please check Horizontal Oscillator and Drive circuit, if this section will function, you will get required voltages.
Please pay attention on horizontal deflection area in your tv.
Hi,
did you found some thing in horizontal deflection area?
does horizontal out put transistor work?
Alright, as you gone through in service manual and know very much about tv, please disable protection circuit for a while to figure out what exactly problem in tv and what circuit area is giving problem.
This suggestion needs very much care when apply.
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Your power supply has gone out.it will need replaced.if all you have is a flashing red led you need to have a tech come out and repair it
If E994 has continuity , then C701 is ok. defective C701 gives problem with colors and picture.
If there is no led flashing, and does not turn on at all then is the power unit, test the capacitors on the power board.
Here is a list of the components that can cause shutdown:
I401
I601
C715
E995,E996
T702
Q777,I901
E994,D724
If the red led is flashing, then probably is not the power board.
In your TV the power supply PWB, watching at the back, is the one on the right. At the left you shopuld have the main PWB.
To troubleshoot the problem download the service manual at page 32 and following, then follow the troubleshooting diagrams. There you find what components to test.
I post again the service manual, all in one part, is the same posted by welcomjee
The link to service manual was a free download, you do not have to pay, normally the service manual costs $20 or $30, in Adobe.
I told you to read the service manual because you need to follow a diagram telling you what to test.
If the red led is on, then are not the capacitors on the power board. You need to troubleshoot the problem testing components one by one.
This is the part of the diagram for your situation, when red is on and green off:
Test filter coil Q914, and proceed from there, that is what you need to do.
To test the filter coil, you short it, If you still get no picture you test voltage at Q701, must be 0.3v, then follow instructions on components to be tested.
As usual, if you do not have done a similar job before, call a technician.
I mean the job involves working on TV with live power.
This is an hazard if you do not have a solid background in servicing electronics.
If you want to make it ieasier, test all components at the end of the diagrams, and thest the components I posted before.
You do not need to work with live power, as all you need to test is parts for continuity.
It takes longer but often you spot the problem the same.
If you know what you are doing, then follow the diagram.
To download the manual, click this link: service manual, all in one part, then click the download button, then follow instructions, download is free.
Thanks
You can get parts here, just click.
Or try here.
If you cannot find the part give them a call.
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There is a Red LED flashing (D912), none of the green LED's. Which capacitor(s) are you recommending to check?
Thanks,
Tim
Isn't the power supply part of the main board? Is there any way I can check output of some test points, etc. to make sure?
Thanks,
Thanks for the pointer but I have to pay for the service manual and it's in Adobe.
Still looking for some leads to fix it. Hopefully manual has tips for this problem.
Tim
This is very helpful.. I'll check as much as I can before I call TV repair service. I may need some more helps..
Thanks,
Tim
Well, I followed the troubleshooting flowchart on pages 32-33 as you suggested and my problem seems to be on the (A) path. The voltage at pin 5 of I901 is not right (-42V instead of +10V to +16V). Then I proceeded to check the 5 components it suggested and pretty sure that R905/906 and D907 are OK, not 100% sure about Q901 and C907 (don't know how to check them on PWB). There is no burn mark on any of them..
Any suggestions?
Thanks,
Tim
Where can I get parts for this TV?
Thanks,
Tim
All pico fuses are OK but there is no power after T901. There is 113V at E991. Any experience with this problem?
Thanks,
Tim
I have background in electronic so I can read schematic and use multimeter but not so much on repair. What I want to do is to eliminate the obvious problem that I can service it myself. But if the problem is more than I can handle then I'll definitely call TV repair service. As I posted earlier, from Protection circiut block diagram, I have DC 113V at both end of pico fuse E991 but no DC on the other outputs.
Thanks,
Tim
I don't understand how C707 get into the picture here? I think my problem is on the Power Protection circuit (block diagram page 40 in the service manual).
Thanks,
Tim
Thanks for all the helps. I'll spend Sunday to play around and call repair service on Monday..
Tim
Because the power protection circuit shutdown a few seconds after power up, there is no power anywhere in the H circuitry. I'll have to call the repair service to come look at it.
Thanks for the helps..
Tim.
Thanks all for your suggestions and helpful instructions. Don't be upset that I keep reposting this and have not accepted any solution. I'll take a route to call repair service for this one. I'll post the solution when the TV is fixed.
Thanks again..
Tim
How can I disable protection?
Thanks,
Tim
The problem is fixed by repair service. According to the repair description, it was cold soldered joints on main PCB.
Thanks for your assistance.
Tim
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