Toshiba plasma 50WP16 wierd double image fault

[piershs]

My 2001 Toshiba 50WP16 50" plasma TV has, after 20 years of trouble-free service, developed a wierd fault in the last 14 days during normal viewing - with no loud bang or smoke or any other excitement.

Every 15-30 secs the right hand half of the image has a "glitch" for about 1 second before reverting to normal. The glitch has two forms and also depends on the aspect ratio setting (see photos):

• 16:9 either a) a visible seam between LHS and RHS of impage or b) LHS image duplicated on RHS (photos 16x9)
• 4x3 either a) no image on RHS or b) RHS image offset by 1/6th with v faint ghost image in correct location (photos 4x3)

Image input sources affected: Component, AV and S-VGA (but OSD not affected even when the underlying image glitches)
PC source is NOT affected, works perfectly in 1366x768 native resolution

Running Self-check mode appears to show a fault on the main board "D" with IC9011 showing as missing or faulty (see photo). However, as I can't find an IC9011 on any of the schematics or in the service manual, I can't be sure if this is a genuine fault.

Has anyone seen this kind of fault before?

My guess is that I need a replacement D board, ref.TZTNP010GYS / TNPA1901. These seem to be hard to find outside the US, so before I get too far down that road, I would really appreciate some sage advice from this forum on whether I am on the right track (or not).

Many thanks!

[dick_barton]

Re: Toshiba plasma 50WP16 wierd double image fault

Service manual available from https://www.manualslib.com/download/...a-50wp16a.html
IC9011 is different to the manual

[piershs]

Re: Toshiba plasma 50WP16 wierd double image fault

Thanks for the quick reply. That's the service manual I've been referring to, File No 050-200122 which is dated Oct 2001. My display was actually bought in early 2002, so this manual would have been current for it.

The strange thing is that the manual refers to IC9011 in the self-check section, which matches what I see when I run the test, but then makes no further reference to this IC. Anyway, it suggests I should probably take the back off and check the actual part number on the D board before ordering a replacement, if that is the cause of the display fault.

So the question remains, is IC9011 and/or the D board the cause of these screen glitches? Is there any other troubleshooting I can do? I don't have a digital multimeter at the moment, so am limited in doing component/board based testing

[ener_dk]

Re: Toshiba plasma 50WP16 wierd double image fault

Hi piershs,

I can not find any reference to IC9011 in the service manual other than the selfcheck.
None of the IC's in the selfcheck is in the component list so I don't know what the test if good for?

If you replace the D-Board you need to do these adjustments according to the service manual:
White balance, Pedestal and Sub brightness for NTSC, PAL, HD, PC and 625I signals.

So taking that into consideration it would maybe be a good idea to replace the D-board??
This is my best guess.

/Ener_dk

[dick_barton]

Re: Toshiba plasma 50WP16 wierd double image fault

A quick look through the manual and I couldn't find IC9011 on the schematics although I may have missed it.

The fault looks like its with the lower buffer boards that address the vertical drive of the screen or the board that controls the lower buffer addressing sequence.

Hopefully others could offer their opinion since I've no real experience with plasma sets other than what I read in the Forum.

Perhaps a good clean up, doublechecking all connectors, ensure that all mounting screws are all done up tight and the fans are all working, may help.

[piershs]

Re: Toshiba plasma 50WP16 wierd double image fault

I couldn't see IC9011 in the schematics either

Given the problem is affecting at least 4 of the buffer boards (UR, UC, LR, LC) this points in my mind to a D board problem. The D board block diagram shows it supplying all the lower and upper drive boards, mainly through the discharge control IC (IC9900), but as I have no experience with how plasma sets work this is just an uneducated guess.

I'll take the back off later today to assess it's condition, clean it up and check fans as you suggest

[piershs]

Re: Toshiba plasma 50WP16 wierd double image fault

So, having taken the back off and taken a good look around, what have I learnt?

1. Surprised that there wasn't more dust accumulated inside after 20 years of use. Sure, the fan blades had picked up some fuzz on their leading edges, but elsewhere it was pretty clean

2. No loose connectors that I could see/wiggle or obvious burnt out components (not that I was really expecting to find the latter given the intermittent nature of the fault)

3. The actual D board part no. matches the service manual part no., which is encouraging

4. I managed not to break anything opening it up or putting it back together - when I switched in on, it worked exactly as before (including the fault). I had taken it apart enough to expose the D board fully, but not disconnect it, which meant disconnecting the DG and H boards. They and all the other boards were visually inspected and given a good dusting

5. I'm no closer to identifying more clearly the cause of the fault.

Unless a reader of this thread has seen it before and can suggest a fix, I reckon my next step will have to be to track down a replacement D board. If so, does anyone know if the design changed during its life or am I safe using a board from a display manufactured later?

Second, as a matter of hygiene, and also in hope that fans have got quieter in the last 20 years, can anyone recommend a good replacement part that I can fit at the same time? Original is a Panaflo DC brushless FBL06A12L 12V 0.14A made by Matsushita Electric.

[dick_barton]

Re: Toshiba plasma 50WP16 wierd double image fault

The only other suggestion I can think of is after 20 years you may have solder joints that require touching up. The heating and cooling of the components has a tendancy to crack some solder joints.

[piershs]

Re: Toshiba plasma 50WP16 wierd double image fault

The only other suggestion I can think of is after 20 years you may have solder joints that require touching up. The heating and cooling of the components has a tendancy to crack some solder joints.

Thanks, that's a good thought. Not something I have ever done before, so how does one tell that a joint is cracked?

Should I start with the D board given that is the one that failed the Self-Check?

[dick_barton]

Re: Toshiba plasma 50WP16 wierd double image fault

Here are some examples. Components that heat up tend to crack the solder joints and on close inspection will often reveal the fault. Also around transformers and large coils likewise.

https://learn.adafruit.com/adafruit-...ommon-problems

http://www.discovercircuits.com/dc-m...ue_11/pg-3.htm